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digitalmars.D - Re: OT: on IDEs and code writing on steroids

reply bearophile <bearophileHUGS lycos.com> writes:
Yigal Chripun:

 first, typos - eclipse has a built-in spell checker so all those 
 "lenght" will be underlined with an orange squiggly line.

A much better solution is to use "size" (or even "len") everywhere in D, that avoids such typos in the first place. An IDE is useful, but it's better to improve the language first, so later you don't use the IDE to write boilerplate or fix typos. -----------------
If we ignore this fact D will become another niche academic language that no
one uses.<

Unfortunately I think the academy isn't much interested in D. So if D doesn't succeed, it will just be a dead language. Currently there are only few things that make D better than C#4 (and F#, that is different). Note that in C#4 there are ways to generate code on the fly, this is done much less often than template programming in D, but it's doable.
second, D needs to update its stone age compilation model copied from C++.<

Yes. Eventually Walter will need to take a look at way people write C#, and update D. "moons" files that bundle modules, built-in bud-like functionality, DDLs and more. Things to think about. Bye, bearophile
May 18 2009
parent reply davidl <davidl nospam.org> writes:
在 Mon, 18 May 2009 16:01:56 +0800,bearophile <bearophileHUGS lycos.com>  
写道:

 Yigal Chripun:

 first, typos - eclipse has a built-in spell checker so all those
 "lenght" will be underlined with an orange squiggly line.

A much better solution is to use "size" (or even "len") everywhere in D, that avoids such typos in the first place. An IDE is useful, but it's better to improve the language first, so later you don't use the IDE to write boilerplate or fix typos. -----------------
 If we ignore this fact D will become another niche academic language  
 that no one uses.<

Unfortunately I think the academy isn't much interested in D. So if D doesn't succeed, it will just be a dead language. Currently there are only few things that make D better than C#4 (and F#, that is different). Note that in C#4 there are ways to generate code on the fly, this is done much less often than template programming in D, but it's doable.
 second, D needs to update its stone age compilation model copied from  
 C++.<

Yes. Eventually Walter will need to take a look at way people write C#, and update D. "moons" files that bundle modules, built-in bud-like functionality, DDLs and more. Things to think about. Bye, bearophile

From a commercial basis for Walter, it may be easier to glue a C# frontend against the DMD backend to create a native C# compiler. Waiting D to be a successful language requires a longer time. And people needs higher cost to move to D. Reusing current .Net codebase is a very strong selling point. C# does many correct decisions, better identifier resolve. Its frontend is considered to be written very high quality. Adding stuff on top of C# frontend may be an easier approach. Some people want to compile C# source to native either with the purpose of closing their source and obtaining higher performance. C# gets much bigger code base than D code base. Most importantly, you can not ignore the brilliance of the .Net framework. -- 使用 Opera 革命性的电子邮件客户程序: http://www.opera.com/mail/
May 18 2009
next sibling parent "Tim Matthews" <tim.matthews7 gmail.com> writes:
On Tue, 19 May 2009 00:37:21 +1200, davidl <davidl nospam.org> wrote:


  From a commercial basis for Walter, it may be easier to glue a C#  
 frontend against the DMD backend to create a native C# compiler. Waiting  
 D to be a successful language requires a longer time. And people needs  
 higher cost to move to D. Reusing current .Net codebase is a very strong  
 selling point.
 C# does many correct decisions, better identifier resolve. Its frontend  
 is considered to be written very high quality. Adding stuff on top of C#  
 frontend may be an easier approach.
 Some people want to compile C# source to native either with the purpose  
 of closing their source and obtaining higher performance.
 C# gets much bigger code base than D code base. Most importantly, you  
 can not ignore the brilliance of the .Net framework.

A project in the making that uses D language compiled to cil and can therefore call .net base framework code. http://the-free-meme.blogspot.com/
May 18 2009
prev sibling next sibling parent reply Andrei Alexandrescu <SeeWebsiteForEmail erdani.org> writes:
davidl wrote:
 在 Mon, 18 May 2009 16:01:56 +0800,bearophile 
 <bearophileHUGS lycos.com> 写道:
 
 Yigal Chripun:

 first, typos - eclipse has a built-in spell checker so all those
 "lenght" will be underlined with an orange squiggly line.

A much better solution is to use "size" (or even "len") everywhere in D, that avoids such typos in the first place. An IDE is useful, but it's better to improve the language first, so later you don't use the IDE to write boilerplate or fix typos. -----------------
 If we ignore this fact D will become another niche academic language 
 that no one uses.<

Unfortunately I think the academy isn't much interested in D. So if D doesn't succeed, it will just be a dead language. Currently there are only few things that make D better than C#4 (and F#, that is different). Note that in C#4 there are ways to generate code on the fly, this is done much less often than template programming in D, but it's doable.
 second, D needs to update its stone age compilation model copied from 
 C++.<

Yes. Eventually Walter will need to take a look at way people write C#, and update D. "moons" files that bundle modules, built-in bud-like functionality, DDLs and more. Things to think about. Bye, bearophile

From a commercial basis for Walter, it may be easier to glue a C# frontend against the DMD backend to create a native C# compiler. Waiting D to be a successful language requires a longer time. And people needs higher cost to move to D. Reusing current .Net codebase is a very strong selling point. C# does many correct decisions, better identifier resolve. Its frontend is considered to be written very high quality. Adding stuff on top of C# frontend may be an easier approach. Some people want to compile C# source to native either with the purpose of closing their source and obtaining higher performance. C# gets much bigger code base than D code base. Most importantly, you can not ignore the brilliance of the .Net framework.

I've repeatedly failed to figure out the coolness of C#, and would appreciate a few pointers. Or references. Or delegates :o). Andrei
May 18 2009
next sibling parent reply BCS <ao pathlink.com> writes:
Reply to Andrei,

 I've repeatedly failed to figure out the coolness of C#, and would
 appreciate a few pointers. Or references. Or delegates :o).
 

The coolness of c# is that (in order, IMHO) 1) the tools are world class, 2) the support is back by MS, 3) the docs are great, and 4) the language is highly consistent and conservative, e.i. nothing is added until they've got it right. Aside from #4, the *language* isn't anything to write home about.
 Andrei
 

May 18 2009
next sibling parent reply Ary Borenszweig <ary esperanto.org.ar> writes:
BCS wrote:
 Reply to Andrei,
 
 I've repeatedly failed to figure out the coolness of C#, and would
 appreciate a few pointers. Or references. Or delegates :o).

The coolness of c# is that (in order, IMHO) 1) the tools are world class, 2) the support is back by MS, 3) the docs are great, and 4) the language is highly consistent and conservative, e.i. nothing is added until they've got it right. Aside from #4, the *language* isn't anything to write home about.

Have you seen Linq? That's *amazing*! You can deal with expression ASTs and do really cool stuff with that. Like doing: var results = someObjectsThatAreGoingToBeTakenFromTheDb.Where(o => o.Name == "Foo"); foreach(var result in results) { // There, the previous condition with the given expression has been // translated to SQL and executed. } I find C# a really nice language.
May 18 2009
next sibling parent reply BCS <ao pathlink.com> writes:
Reply to Ary,

 BCS wrote:
 
 Reply to Andrei,
 
 I've repeatedly failed to figure out the coolness of C#, and would
 appreciate a few pointers. Or references. Or delegates :o).
 

class, 2) the support is back by MS, 3) the docs are great, and 4) the language is highly consistent and conservative, e.i. nothing is added until they've got it right. Aside from #4, the *language* isn't anything to write home about.


LINQ is the only thing c# has the is a notable language feature, but I don't think it adds anything that puts it much above the rest of the crowd in any way.
 You can deal with expression ASTs and do really cool stuff with that.
 Like doing:
 
 var results = someObjectsThatAreGoingToBeTakenFromTheDb.Where(o =>
 o.Name == "Foo");

I think this will work: int delegate(int delegate(ref T)) Where(T[] array, bool delegate(T) dg) { struct Ret { T[] Array; bool delegate(T) Dg; int opApply(int delegate(ref T) idg) { foreach(ref T t; Array) if(Dg(t)) if(int ret = idg) return ret; return ret; } return &(Ret(array,dg)).opApply; } } If not, a little tweeking shloudl cover it. There is a lib I played around with a whole back that showed that D can do AST manipulation with expressions.
 foreach(var result in results) {
 // There, the previous condition with the given expression has been
 // translated to SQL and executed.
 }
 I find C# a really nice language.
 

I do to, but mostly because of the tools
May 18 2009
parent reply Ary Borenszweig <ary esperanto.org.ar> writes:
BCS wrote:
 Reply to Ary,
 
 BCS wrote:

 Reply to Andrei,

 I've repeatedly failed to figure out the coolness of C#, and would
 appreciate a few pointers. Or references. Or delegates :o).

class, 2) the support is back by MS, 3) the docs are great, and 4) the language is highly consistent and conservative, e.i. nothing is added until they've got it right. Aside from #4, the *language* isn't anything to write home about.


LINQ is the only thing c# has the is a notable language feature, but I don't think it adds anything that puts it much above the rest of the crowd in any way.
 You can deal with expression ASTs and do really cool stuff with that.
 Like doing:

 var results = someObjectsThatAreGoingToBeTakenFromTheDb.Where(o =>
 o.Name == "Foo");

I think this will work: int delegate(int delegate(ref T)) Where(T[] array, bool delegate(T) dg) { struct Ret { T[] Array; bool delegate(T) Dg; int opApply(int delegate(ref T) idg) { foreach(ref T t; Array) if(Dg(t)) if(int ret = idg) return ret; return ret; } return &(Ret(array,dg)).opApply; } } If not, a little tweeking shloudl cover it.

This is for filtering an array. What this does in C# is to translate that code into this (more or less, this is just the idea!): SqlConnection conn = ...; conn.executeQuery("select * from SomeTable Where Name = 'Foo'"); What the "Where" method does it to receieve an expression tree for "o => o.Name = 'Foo'", and using a visitor it converts it to an SQL statement. In D you don't have expression trees. The best you could do it to give it a string, but then you loose autocompletion, refactoring, nice compiler error messages and probably many other things. The best thing about this is that the expression is represented using a class, say Func<From, To>. So you could say: Func<From, bool> predicate = (From f) => f.Name == "Foo"; Now you can do: From[] array = ...; array.Where(predicate); or: DbObjects.Where(predicate); In the first case, the predicate will be executed at run-time for each object in the array, much like your D example does. In the second case, however, predicate will be translated to SQL.
May 18 2009
parent reply BCS <ao pathlink.com> writes:
Reply to Ary,

 BCS wrote:
 
 Reply to Ary,
 
 Have you seen Linq? That's *amazing*!
 

I don't think it adds anything that puts it much above the rest of the crowd in any way.
 You can deal with expression ASTs and do really cool stuff with
 that. Like doing:
 
 var results = someObjectsThatAreGoingToBeTakenFromTheDb.Where(o =>
 o.Name == "Foo");
 

int delegate(int delegate(ref T)) Where(T[] array, bool delegate(T) dg) { struct Ret { T[] Array; bool delegate(T) Dg; int opApply(int delegate(ref T) idg) { foreach(ref T t; Array) if(Dg(t)) if(int ret = idg) return ret; return ret; } return &(Ret(array,dg)).opApply; } } If not, a little tweeking shloudl cover it.

that code into this (more or less, this is just the idea!): SqlConnection conn = ...; conn.executeQuery("select * from SomeTable Where Name = 'Foo'");

Only for LINQ to SQL (or the like) all LINQ is is a set of standard nameing conventions and sugar. I Add a "Where" function to some SQL tabel object and you get the above as well.
 What the "Where" method does it to receieve an expression tree for "o
 => o.Name = 'Foo'", and using a visitor it converts it to an SQL
 statement. In D you don't have expression trees. The best you could do
 it to give it a string, but then you loose autocompletion,
 refactoring, nice compiler error messages and probably many other
 things.

I can see a Where!("Name","Age>")(someName,someAge) being not to hard to implement. Heck with prepared statements it might even be trivial, maybe even non templated.
 
 The best thing about this is that the expression is represented using
 a class, say Func<From, To>. So you could say:
 
 Func<From, bool> predicate = (From f) => f.Name == "Foo";
 
 Now you can do:
 
 From[] array = ...;
 array.Where(predicate);
 or:
 
 DbObjects.Where(predicate);
 
 In the first case, the predicate will be executed at run-time for each
 object in the array, much like your D example does. In the second
 case, however, predicate will be translated to SQL.
 

OK you've got me convinced that c# has a cool feature: not LINQ (it's still ho-hum) but AST reflection.
May 18 2009
next sibling parent Ary Borenszweig <ary esperanto.org.ar> writes:
BCS wrote:
 Reply to Ary,
 
 BCS wrote:

 Reply to Ary,

 Have you seen Linq? That's *amazing*!

I don't think it adds anything that puts it much above the rest of the crowd in any way.
 You can deal with expression ASTs and do really cool stuff with
 that. Like doing:

 var results = someObjectsThatAreGoingToBeTakenFromTheDb.Where(o =>
 o.Name == "Foo");

int delegate(int delegate(ref T)) Where(T[] array, bool delegate(T) dg) { struct Ret { T[] Array; bool delegate(T) Dg; int opApply(int delegate(ref T) idg) { foreach(ref T t; Array) if(Dg(t)) if(int ret = idg) return ret; return ret; } return &(Ret(array,dg)).opApply; } } If not, a little tweeking shloudl cover it.

that code into this (more or less, this is just the idea!): SqlConnection conn = ...; conn.executeQuery("select * from SomeTable Where Name = 'Foo'");

Only for LINQ to SQL (or the like) all LINQ is is a set of standard nameing conventions and sugar. I Add a "Where" function to some SQL tabel object and you get the above as well.
 What the "Where" method does it to receieve an expression tree for "o
 => o.Name = 'Foo'", and using a visitor it converts it to an SQL
 statement. In D you don't have expression trees. The best you could do
 it to give it a string, but then you loose autocompletion,
 refactoring, nice compiler error messages and probably many other
 things.

I can see a Where!("Name","Age>")(someName,someAge) being not to hard to implement. Heck with prepared statements it might even be trivial, maybe even non templated.
 The best thing about this is that the expression is represented using
 a class, say Func<From, To>. So you could say:

 Func<From, bool> predicate = (From f) => f.Name == "Foo";

 Now you can do:

 From[] array = ...;
 array.Where(predicate);
 or:

 DbObjects.Where(predicate);

 In the first case, the predicate will be executed at run-time for each
 object in the array, much like your D example does. In the second
 case, however, predicate will be translated to SQL.

OK you've got me convinced that c# has a cool feature: not LINQ (it's still ho-hum) but AST reflection.

Yes, sorry. Sometimes I mix both things. It's AST reflection that's nice about C#. Linq is just a nice usage example of it. :-)
May 18 2009
prev sibling parent reply Lutger <lutger.blijdestijn gmail.com> writes:
BCS wrote:

...
 
 all LINQ is is a set of standard nameing conventions and sugar. I Add a
"Where" 
 function to some SQL tabel object and you get the above as well.
 

Not really, LINQ is 'sugar' for the underlying libraries that implements querying. Instead of calling it just sugar, it is more proper to call it a language in it's own right. LINQ to SQL is just one thing, the power of LINQ is that you separate queries from source of data. You can write one query (ideally) that works with SQL, XML or plain Arrays. It's not only that you don't have to write SQL queries anymore, a lot of messy for/while/etc. loops can be totally replaced with LINQ queries too.
May 19 2009
next sibling parent BCS <ao pathlink.com> writes:
Reply to Lutger,

 BCS wrote:
 
 ...
 
 all LINQ is is a set of standard nameing conventions and sugar. I Add
 a "Where" function to some SQL tabel object and you get the above as
 well.
 

Not really, LINQ is 'sugar' for the underlying libraries that

As far as language features go, I'm even less impressed with sugar for libraries.
 implements querying. Instead of calling it just sugar, it is more
 proper to call it a language in it's own right.
 

I still don't think it's anything to spectacular. The AST stuff on the other hand...
May 19 2009
prev sibling parent "Tim Matthews" <tim.matthews7 gmail.com> writes:
On Wed, 20 May 2009 05:40:37 +1200, BCS <ao pathlink.com> wrote:

 Reply to Lutger,

 BCS wrote:
  ...

 all LINQ is is a set of standard nameing conventions and sugar. I Add
 a "Where" function to some SQL tabel object and you get the above as
 well.

Not really, LINQ is 'sugar' for the underlying libraries that

As far as language features go, I'm even less impressed with sugar for libraries.
 implements querying. Instead of calling it just sugar, it is more
 proper to call it a language in it's own right.

I still don't think it's anything to spectacular. The AST stuff on the other hand...

LINQ's syntactic sugar is not bad in my opinion. With .net its more acceptable to have syntactic sugar for a library that it depends on as it is all part of the base framework that is going to be there but with D I think we could all agree that a LINQ like query just doesnt fit in too well (for now at least)
May 19 2009
prev sibling parent Jarrett Billingsley <jarrett.billingsley gmail.com> writes:
On Mon, May 18, 2009 at 1:47 PM, BCS <ao pathlink.com> wrote:

 I think this will work:

 int delegate(int delegate(ref T)) Where(T[] array, bool delegate(T) dg)
 {
 =A0 struct Ret
 =A0 {
 =A0 =A0 =A0 T[] Array;
 =A0 =A0 =A0 bool delegate(T) Dg;

 =A0 =A0 =A0 int opApply(int delegate(ref T) idg)
 =A0 =A0 =A0 {
 =A0 =A0 =A0 =A0 =A0 foreach(ref T t; Array)
 =A0 =A0 =A0 =A0 =A0 =A0 =A0if(Dg(t)) if(int ret =3D idg) return ret;
 =A0 =A0 =A0 =A0 =A0 return ret;
 =A0 =A0 =A0 }
 =A0 =A0 =A0 return &(Ret(array,dg)).opApply;
 =A0 }
 }

 If not, a little tweeking shloudl cover it.

Using that, however, looks pretty ugly: array.Where((SomeObject o) { return o.name =3D=3D "foo"; }); D could really use some sugar for delegate literals, especially tiny 'predicate' literals like this. array.Where(\o -> o.name =3D=3D "foo");
May 18 2009
prev sibling parent reply Christopher Wright <dhasenan gmail.com> writes:
BCS wrote:
 Reply to Andrei,
 
 I've repeatedly failed to figure out the coolness of C#, and would
 appreciate a few pointers. Or references. Or delegates :o).

The coolness of c# is that (in order, IMHO) 1) the tools are world class, 2) the support is back by MS, 3) the docs are great, and 4) the language is highly consistent and conservative, e.i. nothing is added until they've got it right. Aside from #4, the *language* isn't anything to write home about.

I'd say C#2 is Java with the top 10 or so feature requests implemented, and another 5 or so major feature requests implemented each major version. That isn't a bad state to be in, really. It's good enough, with a billion dollars in corporate backing, to make you the Current Big Language.
May 18 2009
parent reply Andrei Alexandrescu <SeeWebsiteForEmail erdani.org> writes:
Christopher Wright wrote:
 BCS wrote:
 Reply to Andrei,

 I've repeatedly failed to figure out the coolness of C#, and would
 appreciate a few pointers. Or references. Or delegates :o).

The coolness of c# is that (in order, IMHO) 1) the tools are world class, 2) the support is back by MS, 3) the docs are great, and 4) the language is highly consistent and conservative, e.i. nothing is added until they've got it right. Aside from #4, the *language* isn't anything to write home about.

I'd say C#2 is Java with the top 10 or so feature requests implemented,

I can confirm straight from the source (important person, name undisclosed to protect the innocent) that it is true that C# was without any buts and ands Microsoft's direct response to Java.
 and another 5 or so major feature requests implemented each major 
 version. That isn't a bad state to be in, really. It's good enough, with 
 a billion dollars in corporate backing, to make you the Current Big 
 Language.

I have the feeling that C#, for all its features, lacks some pretty essential capabilities. Andrei
May 18 2009
parent reply Ary Borenszweig <ary esperanto.org.ar> writes:
Andrei Alexandrescu escribi:
 Christopher Wright wrote:
 BCS wrote:
 Reply to Andrei,

 I've repeatedly failed to figure out the coolness of C#, and would
 appreciate a few pointers. Or references. Or delegates :o).

The coolness of c# is that (in order, IMHO) 1) the tools are world class, 2) the support is back by MS, 3) the docs are great, and 4) the language is highly consistent and conservative, e.i. nothing is added until they've got it right. Aside from #4, the *language* isn't anything to write home about.

I'd say C#2 is Java with the top 10 or so feature requests implemented,

I can confirm straight from the source (important person, name undisclosed to protect the innocent) that it is true that C# was without any buts and ands Microsoft's direct response to Java.
 and another 5 or so major feature requests implemented each major 
 version. That isn't a bad state to be in, really. It's good enough, 
 with a billion dollars in corporate backing, to make you the Current 
 Big Language.

I have the feeling that C#, for all its features, lacks some pretty essential capabilities.

Like...?
May 18 2009
parent "Nick Sabalausky" <a a.a> writes:
"Ary Borenszweig" <ary esperanto.org.ar> wrote in message 
news:gusps3$87l$1 digitalmars.com...
 Andrei Alexandrescu escribi:
 I have the feeling that C#, for all its features, lacks some pretty 
 essential capabilities.

Like...?

Templates that don't suck.
May 19 2009
prev sibling next sibling parent Robert Fraser <fraserofthenight gmail.com> writes:
Steven Schveighoffer wrote:
 The IDE is excellent.  The docs are reasonable once you figure out how 
 they are laid out.

I really don't get what's so great about VS. After using JDT (Eclipse Java), I find Vs kind of lacking. IMO, MS invests a lot of resources in areas to sell VS to companies rather than programmers. Automatic checking against UML models... okay, that's a cool feature, but I'd rather it could highlight my semantic errors without my having to click "build" or have more than 5 refactorings or have quick-fixes for errors, or...
May 18 2009
prev sibling next sibling parent davidl <davidl nospam.org> writes:
在 Tue, 19 May 2009 00:14:50 +0800,BCS <ao pathlink.com> 写道:

 Reply to Andrei,

 I've repeatedly failed to figure out the coolness of C#, and would
 appreciate a few pointers. Or references. Or delegates :o).

The coolness of c# is that (in order, IMHO) 1) the tools are world class, 2) the support is back by MS, 3) the docs are great, and 4) the language is highly consistent and conservative, e.i. nothing is added until they've got it right. Aside from #4, the *language* isn't anything to write home about.
 Andrei


The fact is MS has paven the way for getting people who uses C# open their source by default(lot of code can be disassembled). Reusing them itself is a very strong selling point. The market has a will to both reusing C# code while keeping the commercial secret. They don't want the others disassemble the app and tweak a little bit and rebuild the app(this is always possible if you don't strip the IL by only obfuscating it. For native cases, you would have a much higher barrier to rebuild others' app). The first 3 points can be shared with MS if we keep at a reasonable consistency with MS stuff. If we have the C# frontend and major .Net framework API, the tools can be built immediately by compiling SharpDevelop, which is also considered to be high quality to use. -- 使用 Opera 革命性的电子邮件客户程序: http://www.opera.com/mail/
May 18 2009
prev sibling next sibling parent reply "Nick Sabalausky" <a a.a> writes:
"Andrei Alexandrescu" <SeeWebsiteForEmail erdani.org> wrote in message 
news:gus0lu$1smj$2 digitalmars.com...

 I've repeatedly failed to figure out the coolness of C#, and would 
 appreciate a few pointers. Or references. Or delegates :o).

Outside of this group, I think most of the people considering C# really cool are people who are unaware of D and are coming to C# from Java. What's "cool" about C# is that it's like a less-shitty version of Java (and *had* good tools, although the newer versions of VS are almost as much of a bloated unresponsive mess as Eclipse - Which come to think of it, makes me wonder - If Java has gotten so fast as many people claim, why is Eclipse still such a sluggish POS?). Compare C# to D though and most of the coolness fades, even though there are still a handful of things I think D could still learn from C# (but there's probably more than a handful that C# could learn from D).
May 19 2009
next sibling parent BCS <none anon.com> writes:
Hello Nick,

 If Java has gotten so fast as many
 people claim, why is Eclipse still such a sluggish POS?).
 

for the same reason that anything is slow, people more than make up for any gains in perf with more features (and shoddy code)
May 19 2009
prev sibling parent reply Christopher Wright <dhasenan gmail.com> writes:
Nick Sabalausky wrote:
 "Andrei Alexandrescu" <SeeWebsiteForEmail erdani.org> wrote in message 
 news:gus0lu$1smj$2 digitalmars.com...
 
 I've repeatedly failed to figure out the coolness of C#, and would 
 appreciate a few pointers. Or references. Or delegates :o).

Outside of this group, I think most of the people considering C# really cool are people who are unaware of D and are coming to C# from Java. What's "cool" about C# is that it's like a less-shitty version of Java (and *had* good tools, although the newer versions of VS are almost as much of a bloated unresponsive mess as Eclipse - Which come to think of it, makes me wonder - If Java has gotten so fast as many people claim, why is Eclipse still such a sluggish POS?). Compare C# to D though and most of the coolness fades, even though there are still a handful of things I think D could still learn from C# (but there's probably more than a handful that C# could learn from D).

Generics and reflection. Generics just hide a lot of casts, usually, but that's still quite useful. And autoboxing is convenient, though not appropriate for D.
May 19 2009
parent reply dsimcha <dsimcha yahoo.com> writes:
== Quote from Christopher Wright (dhasenan gmail.com)'s article
 Nick Sabalausky wrote:
 "Andrei Alexandrescu" <SeeWebsiteForEmail erdani.org> wrote in message
 news:gus0lu$1smj$2 digitalmars.com...

 I've repeatedly failed to figure out the coolness of C#, and would
 appreciate a few pointers. Or references. Or delegates :o).

Outside of this group, I think most of the people considering C# really cool are people who are unaware of D and are coming to C# from Java. What's "cool" about C# is that it's like a less-shitty version of Java (and *had* good tools, although the newer versions of VS are almost as much of a bloated unresponsive mess as Eclipse - Which come to think of it, makes me wonder - If Java has gotten so fast as many people claim, why is Eclipse still such a sluggish POS?). Compare C# to D though and most of the coolness fades, even though there are still a handful of things I think D could still learn from C# (but there's probably more than a handful that C# could learn from D).

that's still quite useful. And autoboxing is convenient, though not appropriate for D.

What the heck do you need generics for when you have real templates? To me, generics seem like just a lame excuse for templates.
May 19 2009
next sibling parent reply Andrei Alexandrescu <SeeWebsiteForEmail erdani.org> writes:
dsimcha wrote:
 == Quote from Christopher Wright (dhasenan gmail.com)'s article
 Nick Sabalausky wrote:
 "Andrei Alexandrescu" <SeeWebsiteForEmail erdani.org> wrote in message
 news:gus0lu$1smj$2 digitalmars.com...

 I've repeatedly failed to figure out the coolness of C#, and would
 appreciate a few pointers. Or references. Or delegates :o).

are people who are unaware of D and are coming to C# from Java. What's "cool" about C# is that it's like a less-shitty version of Java (and *had* good tools, although the newer versions of VS are almost as much of a bloated unresponsive mess as Eclipse - Which come to think of it, makes me wonder - If Java has gotten so fast as many people claim, why is Eclipse still such a sluggish POS?). Compare C# to D though and most of the coolness fades, even though there are still a handful of things I think D could still learn from C# (but there's probably more than a handful that C# could learn from D).

that's still quite useful. And autoboxing is convenient, though not appropriate for D.

What the heck do you need generics for when you have real templates? To me, generics seem like just a lame excuse for templates.

I agree. Then, templates aren't easy to implement and they were understandably already busy implementing the using statement. Andrei
May 19 2009
parent reply Lutger <lutger.blijdestijn gmail.com> writes:
Andrei Alexandrescu wrote:

...
 What the heck do you need generics for when you have real templates?  To me,
 generics seem like just a lame excuse for templates.

I agree. Then, templates aren't easy to implement and they were understandably already busy implementing the using statement. Andrei

While I don't fully understand how generics work under the hood in .NET, there are some benefits to how it is done. For example, you can use runtime reflection on generic types. And the jit compiler instantiates them at runtime. They may serve a different purpose than templates: "Anders Hejlsberg: To me the best way to understand the distinction between C# generics and C++ templates is this: C# generics are really just like classes, except they have a type parameter. C++ templates are really just like macros, except they look like classes." It seems that lack of structural typing is seen as a feature: "When you think about it, constraints are a pattern matching mechanism. You want to be able to say, "This type parameter must have a constructor that takes two arguments, implement operator+, have this static method, has these two instance methods, etc." The question is, how complicated do you want this pattern matching mechanism to be? There's a whole continuum from nothing to grand pattern matching. We think it's too little to say nothing, and the grand pattern matching becomes very complicated, so we're in- between." From: http://www.artima.com/intv/genericsP.html
May 19 2009
next sibling parent reply "Nick Sabalausky" <a a.a> writes:
"Lutger" <lutger.blijdestijn gmail.com> wrote in message 
news:gv090o$225$1 digitalmars.com...
 Andrei Alexandrescu wrote:

 ...
 What the heck do you need generics for when you have real templates?  To 
 me,
 generics seem like just a lame excuse for templates.

I agree. Then, templates aren't easy to implement and they were understandably already busy implementing the using statement. Andrei

While I don't fully understand how generics work under the hood in .NET, there are some benefits to how it is done. For example, you can use runtime reflection on generic types. And the jit compiler instantiates them at runtime. They may serve a different purpose than templates: "Anders Hejlsberg: To me the best way to understand the distinction between C# generics and C++ templates is this: C# generics are really just like classes, except they have a type parameter. C++ templates are really just like macros, except they look like classes." It seems that lack of structural typing is seen as a feature: "When you think about it, constraints are a pattern matching mechanism. You want to be able to say, "This type parameter must have a constructor that takes two arguments, implement operator+, have this static method, has these two instance methods, etc." The question is, how complicated do you want this pattern matching mechanism to be? There's a whole continuum from nothing to grand pattern matching. We think it's too little to say nothing, and the grand pattern matching becomes very complicated, so we're in- between." From: http://www.artima.com/intv/genericsP.html

I can see certain potential benefits to the general way C# does generics, but until the old (and I do mean old) issue of "There's an IComparable, so why the hell won't MS give us an IArithmetic so we can actually use arithmetic operators on generic code?" gets fixed (and at this point I'm convinced they've never had any intent of ever fixing that), I don't care how valid the reasoning behind C#'s general approach to generics is, the actual state of C#'s generics still falls squarely into the categories of "crap" and "almost useless".
May 20 2009
parent reply Christopher Wright <dhasenan gmail.com> writes:
Nick Sabalausky wrote:
 I can see certain potential benefits to the general way C# does generics, 
 but until the old (and I do mean old) issue of "There's an IComparable, so 
 why the hell won't MS give us an IArithmetic so we can actually use 
 arithmetic operators on generic code?" gets fixed (and at this point I'm 
 convinced they've never had any intent of ever fixing that), I don't care 
 how valid the reasoning behind C#'s general approach to generics is, the 
 actual state of C#'s generics still falls squarely into the categories of 
 "crap" and "almost useless". 

IArithmetic is impossible in C# because operator overloads are static methods, and interfaces cannot specify static methods.
May 20 2009
parent reply "Nick Sabalausky" <a a.a> writes:
"Christopher Wright" <dhasenan gmail.com> wrote in message 
news:gv0p4e$uvv$1 digitalmars.com...
 Nick Sabalausky wrote:
 I can see certain potential benefits to the general way C# does generics, 
 but until the old (and I do mean old) issue of "There's an IComparable, 
 so why the hell won't MS give us an IArithmetic so we can actually use 
 arithmetic operators on generic code?" gets fixed (and at this point I'm 
 convinced they've never had any intent of ever fixing that), I don't care 
 how valid the reasoning behind C#'s general approach to generics is, the 
 actual state of C#'s generics still falls squarely into the categories of 
 "crap" and "almost useless".

IArithmetic is impossible in C# because operator overloads are static methods, and interfaces cannot specify static methods.

Then how does IComparable work?
May 20 2009
parent reply Christopher Wright <dhasenan gmail.com> writes:
Nick Sabalausky wrote:
 "Christopher Wright" <dhasenan gmail.com> wrote in message 
 news:gv0p4e$uvv$1 digitalmars.com...
 Nick Sabalausky wrote:
 I can see certain potential benefits to the general way C# does generics, 
 but until the old (and I do mean old) issue of "There's an IComparable, 
 so why the hell won't MS give us an IArithmetic so we can actually use 
 arithmetic operators on generic code?" gets fixed (and at this point I'm 
 convinced they've never had any intent of ever fixing that), I don't care 
 how valid the reasoning behind C#'s general approach to generics is, the 
 actual state of C#'s generics still falls squarely into the categories of 
 "crap" and "almost useless".

methods, and interfaces cannot specify static methods.

Then how does IComparable work?

It uses a member function instead.
May 20 2009
parent reply "Nick Sabalausky" <a a.a> writes:
"Christopher Wright" <dhasenan gmail.com> wrote in message 
news:gv29vn$7a0$1 digitalmars.com...
 Nick Sabalausky wrote:
 "Christopher Wright" <dhasenan gmail.com> wrote in message 
 news:gv0p4e$uvv$1 digitalmars.com...
 Nick Sabalausky wrote:
 I can see certain potential benefits to the general way C# does 
 generics, but until the old (and I do mean old) issue of "There's an 
 IComparable, so why the hell won't MS give us an IArithmetic so we can 
 actually use arithmetic operators on generic code?" gets fixed (and at 
 this point I'm convinced they've never had any intent of ever fixing 
 that), I don't care how valid the reasoning behind C#'s general 
 approach to generics is, the actual state of C#'s generics still falls 
 squarely into the categories of "crap" and "almost useless".

methods, and interfaces cannot specify static methods.

Then how does IComparable work?

It uses a member function instead.

And they can't do the same for arithmetic?
May 20 2009
parent Christopher Wright <dhasenan gmail.com> writes:
Nick Sabalausky wrote:
 "Christopher Wright" <dhasenan gmail.com> wrote in message 
 news:gv29vn$7a0$1 digitalmars.com...
 Nick Sabalausky wrote:
 "Christopher Wright" <dhasenan gmail.com> wrote in message 
 news:gv0p4e$uvv$1 digitalmars.com...
 Nick Sabalausky wrote:
 I can see certain potential benefits to the general way C# does 
 generics, but until the old (and I do mean old) issue of "There's an 
 IComparable, so why the hell won't MS give us an IArithmetic so we can 
 actually use arithmetic operators on generic code?" gets fixed (and at 
 this point I'm convinced they've never had any intent of ever fixing 
 that), I don't care how valid the reasoning behind C#'s general 
 approach to generics is, the actual state of C#'s generics still falls 
 squarely into the categories of "crap" and "almost useless".

methods, and interfaces cannot specify static methods.



And they can't do the same for arithmetic?

I believe the rationale for using static functions is so that you can add null to something. (The indexing operator, mind you, is a member property, so this doesn't always hold.) Additionally, this gets rid of opX_r. In practice, I doubt anyone uses that. But it's too late to make that change.
May 21 2009
prev sibling parent reply Andrei Alexandrescu <SeeWebsiteForEmail erdani.org> writes:
Lutger wrote:
 Andrei Alexandrescu wrote:
 
 ...
 What the heck do you need generics for when you have real templates?  To me,
 generics seem like just a lame excuse for templates.

understandably already busy implementing the using statement. Andrei

While I don't fully understand how generics work under the hood in .NET, there are some benefits to how it is done. For example, you can use runtime reflection on generic types. And the jit compiler instantiates them at runtime. They may serve a different purpose than templates: "Anders Hejlsberg: To me the best way to understand the distinction between C# generics and C++ templates is this: C# generics are really just like classes, except they have a type parameter. C++ templates are really just like macros, except they look like classes." It seems that lack of structural typing is seen as a feature: "When you think about it, constraints are a pattern matching mechanism. You want to be able to say, "This type parameter must have a constructor that takes two arguments, implement operator+, have this static method, has these two instance methods, etc." The question is, how complicated do you want this pattern matching mechanism to be? There's a whole continuum from nothing to grand pattern matching. We think it's too little to say nothing, and the grand pattern matching becomes very complicated, so we're in- between." From: http://www.artima.com/intv/genericsP.html

Oh, so Wal^H^H^Ha friend of mine I was talking to was right: there's some missing of the point point going on. The code generation aspect of templates is a blind spot of the size of Canada. Andrei
May 20 2009
parent reply Yigal Chripun <yigal100 gmail.com> writes:
Andrei Alexandrescu wrote:
 Lutger wrote:
 Andrei Alexandrescu wrote:

 ...
 What the heck do you need generics for when you have real 
 templates?  To me,
 generics seem like just a lame excuse for templates.

understandably already busy implementing the using statement. Andrei

While I don't fully understand how generics work under the hood in .NET, there are some benefits to how it is done. For example, you can use runtime reflection on generic types. And the jit compiler instantiates them at runtime. They may serve a different purpose than templates: "Anders Hejlsberg: To me the best way to understand the distinction between C# generics and C++ templates is this: C# generics are really just like classes, except they have a type parameter. C++ templates are really just like macros, except they look like classes." It seems that lack of structural typing is seen as a feature: "When you think about it, constraints are a pattern matching mechanism. You want to be able to say, "This type parameter must have a constructor that takes two arguments, implement operator+, have this static method, has these two instance methods, etc." The question is, how complicated do you want this pattern matching mechanism to be? There's a whole continuum from nothing to grand pattern matching. We think it's too little to say nothing, and the grand pattern matching becomes very complicated, so we're in- between." From: http://www.artima.com/intv/genericsP.html

Oh, so Wal^H^H^Ha friend of mine I was talking to was right: there's some missing of the point point going on. The code generation aspect of templates is a blind spot of the size of Canada. Andrei

I think you miss the point here. Generics and code generation are two separate and orthogonal features that where conflated together by C++. while you can do powerful stuff with templates it smells of trying to write Haskel code with the C pre-proceesor. if you want to see a clean solution to this issue look at Nemerle. essentially, their AST Macro system provides multi-level compilation. c++ templates are a horrible hack designed to ween off C programmers from using the pre-processor and the D templates provide mostly cosmetic changes to this. they do not solve the bigger design issue.
May 20 2009
next sibling parent reply Andrei Alexandrescu <SeeWebsiteForEmail erdani.org> writes:
Yigal Chripun wrote:
 I think you miss the point here.
 Generics and code generation are two separate and orthogonal features 
 that where conflated together by C++.

It's kind of odd, then, that for example the Generative Programming book (http://www.generative-programming.org) chose to treat the two notions in conjunction.
 while you can do powerful stuff with templates it smells of trying to 
 write Haskel code with the C pre-proceesor.
 if you want to see a clean solution to this issue look at Nemerle.
 essentially, their AST Macro system provides multi-level compilation.
 
 c++ templates are a horrible hack designed to ween off C programmers 
 from using the pre-processor and the D templates provide mostly cosmetic 
  changes to this. they do not solve the bigger design issue.

What is the bigger design issue? Andrei
May 20 2009
parent reply "Nick Sabalausky" <a a.a> writes:
"Bill Baxter" <wbaxter gmail.com> wrote in message 
news:mailman.151.1242855932.13405.digitalmars-d puremagic.com...
 On Wed, May 20, 2009 at 1:09 PM, Andrei Alexandrescu
 <SeeWebsiteForEmail erdani.org> wrote:
 Yigal Chripun wrote:
 I think you miss the point here.
 Generics and code generation are two separate and orthogonal features 
 that
 where conflated together by C++.

It's kind of odd, then, that for example the Generative Programming book (http://www.generative-programming.org) chose to treat the two notions in conjunction.

Yeh, there's definitely a overlap. Orthogonal isn't quite the right word there. I'm reading a bit on C++/CLI right now, which is C++ extended to inter-operate with CLR. C++/CLI has *both* classic C++ templates and CLR generics: template<typename T> ... // all code specializations generated at compile-time (if at all) generic<typename T> ... // code generated at compiletime unconditionally, specialized at run-time. I'm not clear on exactly what happens at runtime in the generic<> case. I had been thinking it was simply that the compiler does some type checking at compile time and the VM code then just manipulates pointers to Object from there. That may be what happens in Java generics, but in CLR generics at least you can specialize on non-Object value types and that apparently does not result in everything getting boxed. So it seems like there's a little something extra going on. I think the main reason for having Generics is that they're the best anyone currently knows how to do at the IL bytecode level. Generics give you a way to define generic parameterized types that work across all the languages that target a given VM's bytecode. But that doesn't preclude any language that targets that VM from *also* implementing compile-time templates, or code generators, or AST macros at the source code level. But the problem with source-level code generation is that you then need the source code in order to use the library. I think they were trying to avoid that with C#. If you have a compiled C# assembly, then you have everything you need to use it. Period. (I think.) At any rate, a tech that requires inclusion of source code is not very interesting to Microsoft, because Microsoft doesn't generally like to let people see their source code in the first place, and they know that many of their biggest customers don't like to either. They're nervous enough about just putting de-compileable bytecode out there.

Maybe this is naive, but what about an AST-level template/generic? Couldn't that provide for the best of both worlds? For instance, suppose (purely hypothetically) that the .NET assembly system were changed to allow the source for a D/C++ style of source-level template to be embedded into the assembly. Then they'd be able to do D/C++ style source-level template/code-generation. Right? Now obviously the big problem with that is it would only be usable in the same language it was originally written in. So, instead of getting that cross-language support by going all the way down to the IL bytecode level to implement generics (which, as you said, would somehow prevent the flexibility that the D/C++ style enjoys) suppose it only went down as far as a language-agnostic AST? I suppose that might make reverse-engineering easier which MS might not like, but I'm not suggesting this as something that MS should like or should even do, but rather suggesting it as (business issues completely aside) something that would possibly gain the benefits of both styles.
May 20 2009
next sibling parent Daniel Keep <daniel.keep.lists gmail.com> writes:
Nick Sabalausky wrote:
 ...
 
 Maybe this is naive, but what about an AST-level template/generic? Couldn't 
 that provide for the best of both worlds?
 
 For instance, suppose (purely hypothetically) that the .NET assembly system 
 were changed to allow the source for a D/C++ style of source-level template 
 to be embedded into the assembly. Then they'd be able to do D/C++ style 
 source-level template/code-generation. Right? Now obviously the big problem 
 with that is it would only be usable in the same language it was originally 
 written in. So, instead of getting that cross-language support by going all 
 the way down to the IL bytecode level to implement generics (which, as you 
 said, would somehow prevent the flexibility that the D/C++ style enjoys) 
 suppose it only went down as far as a language-agnostic AST?
 
 ...

What I've always thought might be an interesting experiment would be to change templates in LDC so that instead of generating an AST, they generate code that generates code. So when you use A!(T), what happens is that at runtime the template is "run" with T as an argument. This generates a chunk of LLVM bitcode which LLVM then assembles to machine code and links into the program. This alleviates the problem with using source in that if you embed the template's actual source, then you suddenly ALSO have to embed the standard library's source and the source of any other libraries you happened to compile with. Oh, and the same version of the compiler. -- Daniel
May 20 2009
prev sibling next sibling parent reply Yigal Chripun <yigal100 gmail.com> writes:
Nick Sabalausky wrote:
 
 Maybe this is naive, but what about an AST-level template/generic? Couldn't 
 that provide for the best of both worlds?
 
 For instance, suppose (purely hypothetically) that the .NET assembly system 
 were changed to allow the source for a D/C++ style of source-level template 
 to be embedded into the assembly. Then they'd be able to do D/C++ style 
 source-level template/code-generation. Right? Now obviously the big problem 
 with that is it would only be usable in the same language it was originally 
 written in. So, instead of getting that cross-language support by going all 
 the way down to the IL bytecode level to implement generics (which, as you 
 said, would somehow prevent the flexibility that the D/C++ style enjoys) 
 suppose it only went down as far as a language-agnostic AST?
 
 I suppose that might make reverse-engineering easier which MS might not 
 like, but I'm not suggesting this as something that MS should like or should 
 even do, but rather suggesting it as (business issues completely aside) 
 something that would possibly gain the benefits of both styles. 
 
 

that's the exact opposite of a good solution. I already mentioned several times before the language Nemerle which provide the correct solution. important fact - Nemerle is a .NET language and it does _NOT_ need to modify the underlining system. The way it works in Nemerle is pretty simple: the language has a syntax to compose/decompose AST. a Macro in nemerle is just a plain old function that uses the same syntax you'd use at run-time and this "function" can use APIs to access the compiler's internal data structures (the AST) and manipulate it. you "connect" it to your regular code by either just calling it like a regular function or by using attributes. let's compare to see the benefits: in D: tango.io.Stdout("Hello World").newline; // prints at run-time pragma(msg, "Hello World"); // prints at compile-time in Nemerle: macro m () { Nemerle.IO.printf ("compile-time\n"); <[ Nemerle.IO.printf ("run-time\n") ]>; } // and you call it like this: m(); Nemerle.IO.printf ("run-time\n"); notice how both use the same code, the same printf function? the only change is that the second line inside the macro is enclosed inside <[ ]> which means output (return) the AST for this code instead of actually running the code and returning the result of the call. Macros in Nemerle need to be compiled since they are regular Nemerle code and they need to be loaded by the compiler (added to the command line) in order to compile the code the calls the macros. essentially these are just plugins for the compiler. compared to the elegance of this solution, templates are just a crude copy-paste mechanism implemented inside the compiler.
May 21 2009
parent reply Andrei Alexandrescu <SeeWebsiteForEmail erdani.org> writes:
Yigal Chripun wrote:
 Nick Sabalausky wrote:
 I suppose that might make reverse-engineering easier which MS might 
 not like, but I'm not suggesting this as something that MS should like 
 or should even do, but rather suggesting it as (business issues 
 completely aside) something that would possibly gain the benefits of 
 both styles.

that's the exact opposite of a good solution. I already mentioned several times before the language Nemerle which provide the correct solution. important fact - Nemerle is a .NET language and it does _NOT_ need to modify the underlining system. The way it works in Nemerle is pretty simple: the language has a syntax to compose/decompose AST. a Macro in nemerle is just a plain old function that uses the same syntax you'd use at run-time and this "function" can use APIs to access the compiler's internal data structures (the AST) and manipulate it. you "connect" it to your regular code by either just calling it like a regular function or by using attributes. let's compare to see the benefits: in D: tango.io.Stdout("Hello World").newline; // prints at run-time pragma(msg, "Hello World"); // prints at compile-time in Nemerle: macro m () { Nemerle.IO.printf ("compile-time\n"); <[ Nemerle.IO.printf ("run-time\n") ]>; } // and you call it like this: m(); Nemerle.IO.printf ("run-time\n"); notice how both use the same code, the same printf function? the only change is that the second line inside the macro is enclosed inside <[ ]> which means output (return) the AST for this code instead of actually running the code and returning the result of the call. Macros in Nemerle need to be compiled since they are regular Nemerle code and they need to be loaded by the compiler (added to the command line) in order to compile the code the calls the macros. essentially these are just plugins for the compiler. compared to the elegance of this solution, templates are just a crude copy-paste mechanism implemented inside the compiler.

Nemerle's interesting, but it has its own issues. The largest one is that it will have to beat history: languages with configurable syntax have failed in droves in the 1970s. Before I got into D, I was working on Enki. Enki was my own programming language and of course made D look like a piece of crap. In Enki, you had only very few primitives related to macro expansion, and you could construct all language elements - if, while, for, structures, classes, exceptions, you name it, from those primitive elements. There were two elements that convinced me to quit Enki. One was that I'd got word of a language called IMP72. IMP72 embedded the very same ideas Enki had, with two exceptions: (1) it was created in 1972, and (2) nobody gave a damn ever since. IMP72 (and there were others too around that time) started with essentially one primitive and then generated itself with a bootstrap routine, notion that completely wowed me and I erroneously thought would have the world wowed too. The second reason was that I've had many coffees and some beers with Walter and he convinced me that configurable syntax is an idea that people just don't like. Thinking a bit more, I realized that humans don't operate well with configurable syntax. To use the hackneyed comparison, no natural language or similar concoction has configurable syntax. Not even musical notation or whatnot. There's one syntax for every human language. I speculated that humans can learn one syntax for a language and then wire their brains to just pattern match semantics using it. Configurable syntax just messes with that approach, and besides makes any program hugely context-dependent and consequently any large program a pile of crap. That being said, I have no idea whether or not Nemerle will be successful. I just speculate it has an uphill battle to win. Andrei
May 21 2009
next sibling parent reply dsimcha <dsimcha yahoo.com> writes:
== Quote from Andrei Alexandrescu (SeeWebsiteForEmail erdani.org)'s
 Before I got into D, I was working on Enki. Enki was my own programming
 language and of course made D look like a piece of crap. In Enki, you
 had only very few primitives related to macro expansion, and you could
 construct all language elements - if, while, for, structures, classes,
 exceptions, you name it, from those primitive elements.
 There were two elements that convinced me to quit Enki. One was that I'd
 got word of a language called IMP72. IMP72 embedded the very same ideas
 Enki had, with two exceptions: (1) it was created in 1972, and (2)
 nobody gave a damn ever since. IMP72 (and there were others too around
 that time) started with essentially one primitive and then generated
 itself with a bootstrap routine, notion that completely wowed me and I
 erroneously thought would have the world wowed too.
 The second reason was that I've had many coffees and some beers with
 Walter and he convinced me that configurable syntax is an idea that
 people just don't like. Thinking a bit more, I realized that humans
 don't operate well with configurable syntax. To use the hackneyed
 comparison, no natural language or similar concoction has configurable
 syntax. Not even musical notation or whatnot. There's one syntax for
 every human language. I speculated that humans can learn one syntax for
 a language and then wire their brains to just pattern match semantics
 using it. Configurable syntax just messes with that approach, and
 besides makes any program hugely context-dependent and consequently any
 large program a pile of crap.
 That being said, I have no idea whether or not Nemerle will be
 successful. I just speculate it has an uphill battle to win.
 Andrei

This is pretty much a special case of a more general statement about customizability. Customizability is good as long as there are also sane default/de facto standard ways of doing things and simple things are still made simple. Take EMacs or vi, for example. I absolutely despise both because they have very annoying, idiosynchratic ways of doing basic stuff like saving a file, navigating through a file, etc. The backspace, delete, home, etc. keys don't always do what I've come to expect them to do out of the box. I know all this stuff is customizable, but the barrier to entry of learning how to configure all this stuff is much higher than the barrier to just using a simple GUI text editor like gedit or Notepad++ instead. I don't care how powerful these programs are, they're still not special enough that violating such basic conventions is acceptable. Bringing this analogy back to language design, if you make a language very highly configurable and don't provide good defaults, the barrier to entry will just be too high. If people have to understand a whole bunch of intricacies of the macro system to do anything more complex than "Hello, world", the language will be confined to a highly devoted niche. On the other hand, if you do provide strong conventions and sane defaults, people will probably avoid violating them because doing so would make their code no longer portable from programmer to programmer, and would probably break a whole bunch of library code, etc. that relies on the convention. In other words, they would feel like they were creating a whole new language, and for all practical purposes they would be. Thus, the purpose of this customizability would be defeated. As I've said before in various places, my favorite thing about D is that it takes a level headed, pragmatic view on so many issues that other languages fight holy wars about. These include performance vs. simplicity, safety vs. flexibility, etc. This is just another one to add to the list. Having a sane subset that's something like a hybrid between Java and Python, but then putting D's template system on top of it for when the sane subset just doesn't cut it is a pragmatic, level-headed solution to the holy war between meta-languages that let (force?) you to customize everything and don't have a well-defined sane, simple subset and excessively rigid static languages that sometimes don't make complex things possible. (Note: Don't get me wrong, IMHO, parts of the template system have actually earned a rightful place in the sane subset, just not the more advanced metaprogramming stuff.)
May 21 2009
parent Andrei Alexandrescu <SeeWebsiteForEmail erdani.org> writes:
dsimcha wrote:
 Bringing this analogy back to language design, if you make a language very
highly
 configurable and don't provide good defaults, the barrier to entry will just be
 too high.  If people have to understand a whole bunch of intricacies of the
macro
 system to do anything more complex than "Hello, world", the language will be
 confined to a highly devoted niche.  On the other hand, if you do provide
strong
 conventions and sane defaults, people will probably avoid violating them
because
 doing so would make their code no longer portable from programmer to
programmer,
 and would probably break a whole bunch of library code, etc. that relies on the
 convention.  In other words, they would feel like they were creating a whole
new
 language, and for all practical purposes they would be.  Thus, the purpose of
this
 customizability would be defeated.

The symptom is visible: even with good defaults and all, such languages invariably come with the advice "don't use our best feature". That's terrible. It's a bad anguage design to put in power that can do more harm than good, to the extent that you openly unrecommend usage of the feature. Like you have a car with a very powerful engine but not a clutch to match (there are many, Subaru Impreza comes to mind). Then you have this awesome power on paper, but invariably the mechanic tells you: don't seal the pedal to the metal if you want to have a car. I therefore much prefer D's templates which I use and also recommend to non-advanced users, plus the occasional string mixin that is a seldom-used feature instrumental to only a minority of idioms. Andrei
May 21 2009
prev sibling next sibling parent reply "Nick Sabalausky" <a a.a> writes:
"Andrei Alexandrescu" <SeeWebsiteForEmail erdani.org> wrote in message 
news:gv3ubr$2ul$1 digitalmars.com...
 Yigal Chripun wrote:

 Nemerle's interesting, but it has its own issues. The largest one is that 
 it will have to beat history: languages with configurable syntax have 
 failed in droves in the 1970s.

 Before I got into D, I was working on Enki. Enki was my own programming 
 language and of course made D look like a piece of crap. In Enki, you had 
 only very few primitives related to macro expansion, and you could 
 construct all language elements - if, while, for, structures, classes, 
 exceptions, you name it, from those primitive elements.

 There were two elements that convinced me to quit Enki. One was that I'd 
 got word of a language called IMP72. IMP72 embedded the very same ideas 
 Enki had, with two exceptions: (1) it was created in 1972, and (2) nobody 
 gave a damn ever since. IMP72 (and there were others too around that time) 
 started with essentially one primitive and then generated itself with a 
 bootstrap routine, notion that completely wowed me and I erroneously 
 thought would have the world wowed too.

There are many possible reasons for a failed language's failure. One of the biggest is lack of visibility. Who has ever heard of IMP72? Sure, that lack of visibility could have been because people hated that particular aspect of the language, but it could also have been from any one of a number of other reasons.
 The second reason was that I've had many coffees and some beers with 
 Walter and he convinced me that configurable syntax is an idea that people 
 just don't like. Thinking a bit more, I realized that humans don't operate 
 well with configurable syntax. To use the hackneyed comparison, no natural 
 language or similar concoction has configurable syntax. Not even musical 
 notation or whatnot. There's one syntax for every human language. I 
 speculated that humans can learn one syntax for a language and then wire 
 their brains to just pattern match semantics using it. Configurable syntax 
 just messes with that approach, and besides makes any program hugely 
 context-dependent and consequently any large program a pile of crap.

So I take it AST Macros are no longer on the table for D3?
May 21 2009
parent Andrei Alexandrescu <SeeWebsiteForEmail erdani.org> writes:
Nick Sabalausky wrote:
 There are many possible reasons for a failed language's failure. One of the 
 biggest is lack of visibility. Who has ever heard of IMP72? Sure, that lack 
 of visibility could have been because people hated that particular aspect of 
 the language, but it could also have been from any one of a number of other 
 reasons.

As I said, there were many languages with configurable syntax created during that period. None was even remembered. But then, correlation is not causation :o).
 The second reason was that I've had many coffees and some beers with 
 Walter and he convinced me that configurable syntax is an idea that people 
 just don't like. Thinking a bit more, I realized that humans don't operate 
 well with configurable syntax. To use the hackneyed comparison, no natural 
 language or similar concoction has configurable syntax. Not even musical 
 notation or whatnot. There's one syntax for every human language. I 
 speculated that humans can learn one syntax for a language and then wire 
 their brains to just pattern match semantics using it. Configurable syntax 
 just messes with that approach, and besides makes any program hugely 
 context-dependent and consequently any large program a pile of crap.

So I take it AST Macros are no longer on the table for D3?

AST macros can be implemented to not allow configurable syntax. Andrei
May 21 2009
prev sibling next sibling parent reply Georg Wrede <georg.wrede iki.fi> writes:
--- Disclaimer: this is a bit long. Read it later. ---

Andrei Alexandrescu wrote:
 Yigal Chripun wrote:
 Macros in Nemerle need to be compiled since they are regular Nemerle 
 code and they need to be loaded by the compiler (added to the command 
 line) in order to compile the code the calls the macros.

 essentially these are just plugins for the compiler.

 compared to the elegance of this solution, templates are just a crude 
 copy-paste mechanism implemented inside the compiler.

Nemerle's interesting, but it has its own issues. The largest one is that it will have to beat history: languages with configurable syntax have failed in droves in the 1970s.

This actually raises a larger issue. IMHO, it's not about configurable syntax, OOP, or any single paradigm. What really matters for a language is, the continuum that the newbie--to--guru programmer faces during his ascent through the language. A *perfect* language should be reasonably usable by the newbie. While he advances, he will encounter both needs and solutions for his increasingly advanced/complex programming projects. Now, *any* serious discontinuity, or forced change of paradigm, will constitute a hurdle. And each such hurdle only serves as a point where this programmer (maybe momentarily, but still), considers other alternatives. If such a point is conspicuous or steep enough, he'll most probably venture to another language. A programming language that has this in mind, will work like Windows: there's always an obvious (who said good?? it's Windows, for crying out loud) way to go, and for you to feel you're advancing on your career.
 Before I got into D, I was working on Enki. Enki was my own programming 
 language and of course made D look like a piece of crap. In Enki, you 
 had only very few primitives related to macro expansion, and you could 
 construct all language elements - if, while, for, structures, classes, 
 exceptions, you name it, from those primitive elements.

Lisp, Forth, anyone???
 There were two elements that convinced me to quit Enki. One was that I'd 
 got word of a language called IMP72. IMP72 embedded the very same ideas 
 Enki had, with two exceptions: (1) it was created in 1972, and (2) 
 nobody gave a damn ever since. IMP72 (and there were others too around 
 that time) started with essentially one primitive and then generated 
 itself with a bootstrap routine, notion that completely wowed me and I 
 erroneously thought would have the world wowed too.

Yeah, the academic honey pot. Always looks seductive in TeX formatted papers!
 The second reason was that I've had many coffees and some beers with 
 Walter and he convinced me that configurable syntax is an idea that 
 people just don't like.

You must forgive him, he's almost as old as I am!!! :O [1]
 Thinking a bit more, I realized that humans don't operate well with
 configurable syntax.

Actually, it's not only about that. Configurable syntax is of course a major issue. But there's an other one. And that's redundancy. In any Real-Life language, there's some amount of redundancy. For example, in many languages, both the predicate and the object are (is this the word) inflected (?), in unison. This gives the ability for the listener to skip (or not hear because of background noise) the ending of either word, and then understand the sentence as a whole. In a similar vein, verbs have a different ending with plural and single, even though the "number" is still available from the rest of the sentence, or simply even the context. Redundancy lets people receive oral communication without undue fixation on single-phoneme differences in the utterance. One might consider that as a form of error checking, like 9-bit parity memory chips. (Something you might want to remember when people ask for compulsory empty parenthesis at the end of functions and methods.) ((See my next paragraph.))
 To use the hackneyed comparison, no natural language or similar
 concoction has configurable syntax. Not even musical notation or
 whatnot. There's one syntax for every human language. I speculated
 that humans can learn one syntax for a language and then wire their
 brains to just pattern match semantics using it. Configurable syntax
 just messes with that approach, and besides makes any program hugely
 context-dependent and consequently any large program a pile of crap.

We may have a continuum here. At the one end is the configurable syntax, at the other end the cast-in-stone regular syntax (which often comes with a reduced vocabulary). I read (IIRC, Sicentific American, late 1970's) that the average size of vocabulary that a (then) working-class London person in a "lesser" neighbourhood used during a week, was only three hundred words! (This factoid was so shocking to me that I will not forget it till the day I'm on my death-bed. I've got more than 40000 words in each of English, Swedish, and Finnish. [4]) As an opposite, take this paragraph from an imaginary math book: "Now, substituting a^e*(2pi*sin(alpha[inverse of the second derivative of beta at the index])) for any first term in every polynomial in the quaternion, it becomes obvious that the derivation needs a temporary extra term, which we will call Z(fab). Now, after the substitution (which we will use thorugh page 34), we now will study the short-term changes in every dimension we're investigating here." Wouldn't you say, this is "configurable syntax". And the poor student doesn't have a choice but to try to follow this crap. (No wonder the working-class guy has no more a chance of ever following this, than the productive, but oh, so challenged member of this newsgroup.) All my musings here, make me write two things: 1: A language has to *provide* an obvious (and followable) path from the ridiculously simple, to the ultimately esoteric, with no (or as few as possible) discontinuities in mind set. (But see [2].) 2: Any _categorical_ statement that contains an implicit assessment of the {audience's|programmer's|critic's} abilities, and their relevance to the level that a particular construct in a language demands, is inherently obsolete. An example is "configurable syntax is an idea that people just don't like".
 That being said, I have no idea whether or not Nemerle will be 
 successful. I just speculate it has an uphill battle to win.

We better make sure D doesn't climb the same hill. And damn sure that the potholes in the D uphill aren't larger than the disciples' stride. --------- [1] Configurable syntax belongs to the same group as recursion. You can program for years without ever needing it (or understanding that you did need it, actually). And then, you see it in a textbook, and all they used it for was Fibonacci. Gee, great, you think, and then you write your own Fibonacci, and then just forget about the whole thing. They simply don't (or didn't, at the time I read textbooks on programming) ever show its relevance in real life everyday programming. (Yes, maybe at that time, hard disks with directory hierarchies were not common. (I used CP/M, couldn't afford UNIX. Neither did they.) Otherwise they'd all have had an example of summing the sizes of files in a directory tree. Which would at once have made the reader feel recursion actually has some relevance to their life.) Configurable syntax isn't exactly what Walter makes his bread and butter on. Neither do I. So neither of us has any reason (today) to use it, or even imagine the benefits of it. Having said that, I remember the time (years ago) when I suggested in this newsgroup that we should have a macro language above the regular programming syntax. I suggested it would be somewhat like Lisp, and it would then let us do some most amazing things, totally inconceivable to us at the time. I almost became the laughing stock of the crowd. (And those things were (mostly) much less amazing than what D templates do now. Except for a little configurable syntax stuff. :-) ) Similarily, I see configurable syntax as a way (somewhat orthogonal to templates, but not fully) of making it possible to *easily* write some kinds of programs that we really can't imagine right now. As an example of how hard it is to get this stuff across, I'll admit to the following: in the old days, I used to imagine that Lisp is the all-powrful super language for _anything_ (except for bit twiddling and systems work), and that if you couldn't do something in Lisp, it was only because of your own limitations as a person. Then, one day, I read that they're implementing macros! I dropped from my chair! If there ever was a language I didn't expect to need macros, Lisp definitely was it. Then, during the next years I read articles that made me believe (I wouldnt be preposterous enough to state I /understood/) that they actually were needed, and that they advanced the applicability of the language significantly. So, configurable syntax for D, I assume *will* be a reality. But I hope it won't be before 2.0 is official. :-( !!!! And while I'm at it, I think that in D4 (not D3) we will have a total overhaul of the current template syntax. (!!!) Yes, it beats the G-string off C++, no question. But that is not enough. And, when you really look at it, the "ease" of D templates is an illusion. The "D like syntax", the "invisibility" of the template system, is only to appease newcomers, to piss off C++ folks, and to delude ourselves. Time will show that it will need to be more overtly Lisp like, and that actually a (sort of) difference in syntax to regular D is well motivated. [2] This is in contrast to the "uphill potholes" I was talking before. Why it's okay (IMHO) to have a slightly different syntax, is, the mental leap from regular programming to templates is huge anyway. And it can't be made to go away either[3]. (Rumtime versus compile time is already hard enough for many. Then we have "is my code producing binary code, or is it producing some other source code? Then what happens? Can that in turn produce yet more source code?? Am I forced to only use this Recursion Stuff all over the place?", etc.) So, then it would only be natural to have a slightly different syntax. That would also give us possiblilities beyond the current ones, to (first partly, and then more completely) implement a system of configurable syntax to D. In the same vein that D still implements an ASM language, there should be a (ehh...) "Higher Level" language at the other end. Precisely like D has never deluded itself of being efficient enough at the Very Low Level to really make ASM obsolete, it should not delude itself with notions of not needing a fundamental VHL (Very High Level) language at the other end. The current Template Language is excellent, beats anybody in sight, but that's not the final answer. And before long C++ #$ #$ will have implemented it, too. Or at least the more marketable details of it. But we have to maintain our lead. And that's done by advancing the bleeding edge so it stays just beyond their reach. [3] One can try to hide a difference by making something "look the same". But that only serves to disorient people. Do you remember that there were *two* mazes in DD. Way past the "xyzzy" graffiti, you ended up in a maze. I spent a whole week around there, before a girlfriend pointed out that "the corridors are alike" but yesterday "the corridors are all different". That's when I understood there were two mazes. No wonder I'd had a feeling of being totally clueless there. Microsoft has made a career of making stuff look alike when they're not, and non-alike when they are. It's poison to rational, intelligent users. But the idiots who just learn by rote memory what to do when, couldn't care less. Or understand the point of our grief. [4] How would you measure how many words you have in a language? The easiest way (back when there were books), was to have somebody else look up a random word in a random page of a dictionary, and ask you to explain it. Do that like 80 times, and then calculate the percentage you got right. Compare that to how many words the dictionary brags of having, usually right on the cover. (You do need a proper dictionary, with more than 50000 words, of course.)
May 21 2009
next sibling parent reply Jason House <jason.house gmail.com> writes:
Georg Wrede Wrote:

 
 --- Disclaimer: this is a bit long. Read it later. ---

Wow, you're right. Sadly, I stopped reading about 80% through (discussion on D4) At a high level, I agree with your assessment about an easy growth path for newbors to gurus. I should also add that a language must make the code of gurus remain understandable for all but the newest of newbies. (Ever try to read through STL or a boost library?) I also had an idea for a configurable syntax language that I almost started developing. The concept was dead simple: 1. Provide the ability to call generated code at compile time. D comes close to this, but D has some restrictions on which code can be called. 2. Expose all compiler primitives for potential use in user code: parse trees, types, IL, raw assembly, etc... 3. Provide hooks to replace specific compilation phases (or wedge tasks between phases) With that, the language was sufficiently capable to morph into any existing language. Everything else, including most language design was "merely" standard library work. My inspiration was seeing various boost libraries such as spirit and lambda. They seemed like the coolest things ever, but all they did was add new syntax for a common coding need. I hadn't heard of LINQ but knew such a thing was feasible in my language...
 Andrei Alexandrescu wrote:
 Yigal Chripun wrote:
 Macros in Nemerle need to be compiled since they are regular Nemerle 
 code and they need to be loaded by the compiler (added to the command 
 line) in order to compile the code the calls the macros.

 essentially these are just plugins for the compiler.

 compared to the elegance of this solution, templates are just a crude 
 copy-paste mechanism implemented inside the compiler.

Nemerle's interesting, but it has its own issues. The largest one is that it will have to beat history: languages with configurable syntax have failed in droves in the 1970s.

This actually raises a larger issue. IMHO, it's not about configurable syntax, OOP, or any single paradigm. What really matters for a language is, the continuum that the newbie--to--guru programmer faces during his ascent through the language. A *perfect* language should be reasonably usable by the newbie. While he advances, he will encounter both needs and solutions for his increasingly advanced/complex programming projects. Now, *any* serious discontinuity, or forced change of paradigm, will constitute a hurdle. And each such hurdle only serves as a point where this programmer (maybe momentarily, but still), considers other alternatives. If such a point is conspicuous or steep enough, he'll most probably venture to another language. A programming language that has this in mind, will work like Windows: there's always an obvious (who said good?? it's Windows, for crying out loud) way to go, and for you to feel you're advancing on your career.
 Before I got into D, I was working on Enki. Enki was my own programming 
 language and of course made D look like a piece of crap. In Enki, you 
 had only very few primitives related to macro expansion, and you could 
 construct all language elements - if, while, for, structures, classes, 
 exceptions, you name it, from those primitive elements.

Lisp, Forth, anyone???
 There were two elements that convinced me to quit Enki. One was that I'd 
 got word of a language called IMP72. IMP72 embedded the very same ideas 
 Enki had, with two exceptions: (1) it was created in 1972, and (2) 
 nobody gave a damn ever since. IMP72 (and there were others too around 
 that time) started with essentially one primitive and then generated 
 itself with a bootstrap routine, notion that completely wowed me and I 
 erroneously thought would have the world wowed too.

Yeah, the academic honey pot. Always looks seductive in TeX formatted papers!
 The second reason was that I've had many coffees and some beers with 
 Walter and he convinced me that configurable syntax is an idea that 
 people just don't like.

You must forgive him, he's almost as old as I am!!! :O [1]
 Thinking a bit more, I realized that humans don't operate well with
 configurable syntax.

Actually, it's not only about that. Configurable syntax is of course a major issue. But there's an other one. And that's redundancy. In any Real-Life language, there's some amount of redundancy. For example, in many languages, both the predicate and the object are (is this the word) inflected (?), in unison. This gives the ability for the listener to skip (or not hear because of background noise) the ending of either word, and then understand the sentence as a whole. In a similar vein, verbs have a different ending with plural and single, even though the "number" is still available from the rest of the sentence, or simply even the context. Redundancy lets people receive oral communication without undue fixation on single-phoneme differences in the utterance. One might consider that as a form of error checking, like 9-bit parity memory chips. (Something you might want to remember when people ask for compulsory empty parenthesis at the end of functions and methods.) ((See my next paragraph.))
 To use the hackneyed comparison, no natural language or similar
 concoction has configurable syntax. Not even musical notation or
 whatnot. There's one syntax for every human language. I speculated
 that humans can learn one syntax for a language and then wire their
 brains to just pattern match semantics using it. Configurable syntax
 just messes with that approach, and besides makes any program hugely
 context-dependent and consequently any large program a pile of crap.

We may have a continuum here. At the one end is the configurable syntax, at the other end the cast-in-stone regular syntax (which often comes with a reduced vocabulary). I read (IIRC, Sicentific American, late 1970's) that the average size of vocabulary that a (then) working-class London person in a "lesser" neighbourhood used during a week, was only three hundred words! (This factoid was so shocking to me that I will not forget it till the day I'm on my death-bed. I've got more than 40000 words in each of English, Swedish, and Finnish. [4]) As an opposite, take this paragraph from an imaginary math book: "Now, substituting a^e*(2pi*sin(alpha[inverse of the second derivative of beta at the index])) for any first term in every polynomial in the quaternion, it becomes obvious that the derivation needs a temporary extra term, which we will call Z(fab). Now, after the substitution (which we will use thorugh page 34), we now will study the short-term changes in every dimension we're investigating here." Wouldn't you say, this is "configurable syntax". And the poor student doesn't have a choice but to try to follow this crap. (No wonder the working-class guy has no more a chance of ever following this, than the productive, but oh, so challenged member of this newsgroup.) All my musings here, make me write two things: 1: A language has to *provide* an obvious (and followable) path from the ridiculously simple, to the ultimately esoteric, with no (or as few as possible) discontinuities in mind set. (But see [2].) 2: Any _categorical_ statement that contains an implicit assessment of the {audience's|programmer's|critic's} abilities, and their relevance to the level that a particular construct in a language demands, is inherently obsolete. An example is "configurable syntax is an idea that people just don't like".
 That being said, I have no idea whether or not Nemerle will be 
 successful. I just speculate it has an uphill battle to win.

We better make sure D doesn't climb the same hill. And damn sure that the potholes in the D uphill aren't larger than the disciples' stride. --------- [1] Configurable syntax belongs to the same group as recursion. You can program for years without ever needing it (or understanding that you did need it, actually). And then, you see it in a textbook, and all they used it for was Fibonacci. Gee, great, you think, and then you write your own Fibonacci, and then just forget about the whole thing. They simply don't (or didn't, at the time I read textbooks on programming) ever show its relevance in real life everyday programming. (Yes, maybe at that time, hard disks with directory hierarchies were not common. (I used CP/M, couldn't afford UNIX. Neither did they.) Otherwise they'd all have had an example of summing the sizes of files in a directory tree. Which would at once have made the reader feel recursion actually has some relevance to their life.) Configurable syntax isn't exactly what Walter makes his bread and butter on. Neither do I. So neither of us has any reason (today) to use it, or even imagine the benefits of it. Having said that, I remember the time (years ago) when I suggested in this newsgroup that we should have a macro language above the regular programming syntax. I suggested it would be somewhat like Lisp, and it would then let us do some most amazing things, totally inconceivable to us at the time. I almost became the laughing stock of the crowd. (And those things were (mostly) much less amazing than what D templates do now. Except for a little configurable syntax stuff. :-) ) Similarily, I see configurable syntax as a way (somewhat orthogonal to templates, but not fully) of making it possible to *easily* write some kinds of programs that we really can't imagine right now. As an example of how hard it is to get this stuff across, I'll admit to the following: in the old days, I used to imagine that Lisp is the all-powrful super language for _anything_ (except for bit twiddling and systems work), and that if you couldn't do something in Lisp, it was only because of your own limitations as a person. Then, one day, I read that they're implementing macros! I dropped from my chair! If there ever was a language I didn't expect to need macros, Lisp definitely was it. Then, during the next years I read articles that made me believe (I wouldnt be preposterous enough to state I /understood/) that they actually were needed, and that they advanced the applicability of the language significantly. So, configurable syntax for D, I assume *will* be a reality. But I hope it won't be before 2.0 is official. :-( !!!! And while I'm at it, I think that in D4 (not D3) we will have a total overhaul of the current template syntax. (!!!) Yes, it beats the G-string off C++, no question. But that is not enough. And, when you really look at it, the "ease" of D templates is an illusion. The "D like syntax", the "invisibility" of the template system, is only to appease newcomers, to piss off C++ folks, and to delude ourselves. Time will show that it will need to be more overtly Lisp like, and that actually a (sort of) difference in syntax to regular D is well motivated. [2] This is in contrast to the "uphill potholes" I was talking before. Why it's okay (IMHO) to have a slightly different syntax, is, the mental leap from regular programming to templates is huge anyway. And it can't be made to go away either[3]. (Rumtime versus compile time is already hard enough for many. Then we have "is my code producing binary code, or is it producing some other source code? Then what happens? Can that in turn produce yet more source code?? Am I forced to only use this Recursion Stuff all over the place?", etc.) So, then it would only be natural to have a slightly different syntax. That would also give us possiblilities beyond the current ones, to (first partly, and then more completely) implement a system of configurable syntax to D. In the same vein that D still implements an ASM language, there should be a (ehh...) "Higher Level" language at the other end. Precisely like D has never deluded itself of being efficient enough at the Very Low Level to really make ASM obsolete, it should not delude itself with notions of not needing a fundamental VHL (Very High Level) language at the other end. The current Template Language is excellent, beats anybody in sight, but that's not the final answer. And before long C++ #$ #$ will have implemented it, too. Or at least the more marketable details of it. But we have to maintain our lead. And that's done by advancing the bleeding edge so it stays just beyond their reach. [3] One can try to hide a difference by making something "look the same". But that only serves to disorient people. Do you remember that there were *two* mazes in DD. Way past the "xyzzy" graffiti, you ended up in a maze. I spent a whole week around there, before a girlfriend pointed out that "the corridors are alike" but yesterday "the corridors are all different". That's when I understood there were two mazes. No wonder I'd had a feeling of being totally clueless there. Microsoft has made a career of making stuff look alike when they're not, and non-alike when they are. It's poison to rational, intelligent users. But the idiots who just learn by rote memory what to do when, couldn't care less. Or understand the point of our grief. [4] How would you measure how many words you have in a language? The easiest way (back when there were books), was to have somebody else look up a random word in a random page of a dictionary, and ask you to explain it. Do that like 80 times, and then calculate the percentage you got right. Compare that to how many words the dictionary brags of having, usually right on the cover. (You do need a proper dictionary, with more than 50000 words, of course.)

May 22 2009
parent reply Georg Wrede <georg.wrede iki.fi> writes:
Jason House wrote:
 Georg Wrede Wrote:
 
 --- Disclaimer: this is a bit long. Read it later. ---


 Wow, you're right. Sadly, I stopped reading about 80% through
 (discussion on D4)

Yeah, one should not write opinion pieces when inspired...
 At a high level, I agree with your assessment about an easy growth
 path for newbors to gurus. I should also add that a language must
 make the code of gurus remain understandable for all but the newest
 of newbies. (Ever try to read through STL or a boost library?)

(Yeah, reading that kind of code makes one feel inferior to the gurus. And so very sad that the language makes even mid-level stuff entirely uncomprehensible. Not to speak of the amounts of time it has to take coding it.) Strictly speaking, there's no way for a language to make guru code understandable to "anti-gurus". However (and what I guess you were thinkng of), when somebody uses the most advanced features in a language, then his stuff should not become incomprehensible to "anti-gurus" just because of the language itself. What I mean is, if somebody does tensor algebra, it's pretty sure a high schooler won't get it, no matter what the language is. *But*, if someone calculates the area of a rectangle or a triangle, using the most advanced language features, then the *language* should not make it incomprehensible to non-gurus, or even "anti-gurus". (I have to admit, no language can guarantee this, but it definitely has to be the aim when designing advanced language features.)
 I also had an idea for a configurable syntax language that I almost
 started developing.

 My inspiration was seeing various boost libraries such as spirit and
 lambda. They seemed like the coolest things ever, but all they did
 was add new syntax for a common coding need.  I hadn't heard of LINQ
 but knew such a thing was feasible in my language...

Spirit and lambda have inspired lots of people. Me too. And LINQ is a cool thing too. When I originally wrote about configurable syntax, LINQ would have made an excellent example of its usefulness. Sadly, I didn't know about it at the time.
May 22 2009
parent Andrei Alexandrescu <SeeWebsiteForEmail erdani.org> writes:
Georg Wrede wrote:
 Jason House wrote:
 Georg Wrede Wrote:

 --- Disclaimer: this is a bit long. Read it later. ---


 Wow, you're right. Sadly, I stopped reading about 80% through
 (discussion on D4)

Yeah, one should not write opinion pieces when inspired...
 At a high level, I agree with your assessment about an easy growth
 path for newbors to gurus. I should also add that a language must
 make the code of gurus remain understandable for all but the newest
 of newbies. (Ever try to read through STL or a boost library?)

(Yeah, reading that kind of code makes one feel inferior to the gurus. And so very sad that the language makes even mid-level stuff entirely uncomprehensible. Not to speak of the amounts of time it has to take coding it.) Strictly speaking, there's no way for a language to make guru code understandable to "anti-gurus". However (and what I guess you were thinkng of), when somebody uses the most advanced features in a language, then his stuff should not become incomprehensible to "anti-gurus" just because of the language itself.

Two possible language features should make complicated template code significantly simpler: 1. Allow inner name promotion even if the template defines other members, as long as they are all private: now: template WidgetImpl(A, B) { ... alias ... Result; } template Widget(A, B) { alias WidgetImpl!(A, B) Widget; } proposed: template Widget(A, B) { private: ... alias ... Result; public: alias Widget Result; } It's needed very frequently, puts sand in the eye, and almost sure to throw off the casual reader. 2. Handle qualifiers and ref properly. Right now I use an abomination: enum bool byRef = is(typeof(&(R.init.front()))); /// UGLY /** Forwards to $(D _input.back). */ mixin( (byRef ? "ref " : "")~ q{ElementType!(R) front() { return _input.back; } }); Andrei
May 22 2009
prev sibling parent bearophile <bearophileHUGS lycos.com> writes:
A configurable syntax has some advantages:
- It makes the language more flexible. I like the idea of this a lot.
- allows to do things that are otherwise hard to do.
- It can be used to write shorter programs.
- It can be used to define a sub-language fitter for a specific job. (Ruby
shows some of this, and CLisp shows lot of this).

A configurable syntax has some disadvantages too (you need some experience to
understand the following points):
- Every program can look different. So you may need lot of time to understand
code written by other people. This is bad if you have 50+ programmers working
on a project.
- The language gets more complex.
- Meta-programming is generally not easy to understand. So newbie programmers
will need more time to learn the language, the entry barrier to the language is
higher.
- It fragments the language community, creating more differences among
programs. This probably leads to a language that has much less already written
modules (example: In Python you can find a module for almost everything. This
sharing of code comes from the syntax that is standard, people using the same
single CPython interpreter, and so on. In Python even the coding style is
codified, there is only one normal way in writing code. This allows people to
share code in a simpler way. And having a rich community of re-usable modules
is probably the most important quality a modern language can have).
- Creating macros is sometimes like extending the language. But the discussions
on the D newsgroups and Python newsgroups have shown me that adding new good
syntax/semantics to a language is a very hard job. So most people that write
macros are going to add bad designs to the language. This is bad.

A silly solution is to have macros only in the standard library and in few
autorized libraries :o] But this is impossible to enforce.

So in the end it may be better to keep finding special and localized situations
where the D language may enjoy becoming a bit more flexible (generic infix
operators? Merging the syntax of compile-time functiong with some templates?
Etc etc) but it may be better to not add a generic configurable syntax (macros)
to D...

Bye,
bearophile
May 22 2009
prev sibling parent reply Yigal Chripun <yigal100 gmail.com> writes:
Andrei Alexandrescu wrote:
 Yigal Chripun wrote:
 Nick Sabalausky wrote:
 I suppose that might make reverse-engineering easier which MS might 
 not like, but I'm not suggesting this as something that MS should 
 like or should even do, but rather suggesting it as (business issues 
 completely aside) something that would possibly gain the benefits of 
 both styles.

that's the exact opposite of a good solution. I already mentioned several times before the language Nemerle which provide the correct solution. important fact - Nemerle is a .NET language and it does _NOT_ need to modify the underlining system. The way it works in Nemerle is pretty simple: the language has a syntax to compose/decompose AST. a Macro in nemerle is just a plain old function that uses the same syntax you'd use at run-time and this "function" can use APIs to access the compiler's internal data structures (the AST) and manipulate it. you "connect" it to your regular code by either just calling it like a regular function or by using attributes. let's compare to see the benefits: in D: tango.io.Stdout("Hello World").newline; // prints at run-time pragma(msg, "Hello World"); // prints at compile-time in Nemerle: macro m () { Nemerle.IO.printf ("compile-time\n"); <[ Nemerle.IO.printf ("run-time\n") ]>; } // and you call it like this: m(); Nemerle.IO.printf ("run-time\n"); notice how both use the same code, the same printf function? the only change is that the second line inside the macro is enclosed inside <[ ]> which means output (return) the AST for this code instead of actually running the code and returning the result of the call. Macros in Nemerle need to be compiled since they are regular Nemerle code and they need to be loaded by the compiler (added to the command line) in order to compile the code the calls the macros. essentially these are just plugins for the compiler. compared to the elegance of this solution, templates are just a crude copy-paste mechanism implemented inside the compiler.

Nemerle's interesting, but it has its own issues. The largest one is that it will have to beat history: languages with configurable syntax have failed in droves in the 1970s. Before I got into D, I was working on Enki. Enki was my own programming language and of course made D look like a piece of crap. In Enki, you had only very few primitives related to macro expansion, and you could construct all language elements - if, while, for, structures, classes, exceptions, you name it, from those primitive elements. There were two elements that convinced me to quit Enki. One was that I'd got word of a language called IMP72. IMP72 embedded the very same ideas Enki had, with two exceptions: (1) it was created in 1972, and (2) nobody gave a damn ever since. IMP72 (and there were others too around that time) started with essentially one primitive and then generated itself with a bootstrap routine, notion that completely wowed me and I erroneously thought would have the world wowed too. The second reason was that I've had many coffees and some beers with Walter and he convinced me that configurable syntax is an idea that people just don't like. Thinking a bit more, I realized that humans don't operate well with configurable syntax. To use the hackneyed comparison, no natural language or similar concoction has configurable syntax. Not even musical notation or whatnot. There's one syntax for every human language. I speculated that humans can learn one syntax for a language and then wire their brains to just pattern match semantics using it. Configurable syntax just messes with that approach, and besides makes any program hugely context-dependent and consequently any large program a pile of crap. That being said, I have no idea whether or not Nemerle will be successful. I just speculate it has an uphill battle to win. Andrei

I didn't talk about configurable syntax at all above. Yes, Nemerle has this feature as part of their Macro system but that's just one rather small aspect about the system that can be removed. I also don't see the bigger problem with it as you describe since this is limited in Nemerle to specific things. I'm also unsure as to what you define as syntax and what you define as semantics. for example, Smalltalk has only 5 keywords and it's implemented entirely as a collection of libraries. "if" "else" "switch" "while" are all implemented as methods of objects and therefore are configurable. Is that also wrong in your opinion? I agree with dsimcha - the language needs to provide simple intuitive defaults, that's why I think LISP didn't succeed. it is very powerful but the need to write your own macro just so you can say "4 + 5" instead of (+ 4 5) shows this point. I think Nemerle provies this - the constructs in Nemerle for the Macro system are very simple and intuitive. you only have one extra syntax feature, the <[ ]>. think of D's CTFE only much more extended in scope - you write a CTFE function and compile it. (that's the Nemerle Macro equivalent) than you just call it in a different file and the compiler will execute this function at compile time. Nemerle does not need an interpreter for this since these functions are compiled just like the rest of the code. Nemerle also provides compiler APIs so these functions could work on AST to add/alter/remove types and other constructs. Last thing, basing your arguments on history is flawed. the Micro-Kernel idea got the same treatment after the failures in the 80's (Mach and co.) but nowadays this idea was revived and there are already several million cellphones that run an OS built on the L4 micro-kernel so it's even a commercial success.
May 21 2009
next sibling parent Andrei Alexandrescu <SeeWebsiteForEmail erdani.org> writes:
Yigal Chripun wrote:
 Last thing, basing your arguments on history is flawed. the Micro-Kernel 
 idea got the same treatment after the failures in the 80's (Mach and 
 co.) but nowadays this idea was revived and there are already several 
 million cellphones that run an OS built on the L4 micro-kernel so it's 
 even a commercial success.

Our industry goes in cycles, and I've been around to see a few (multitasking, microkernels, memory paging, virtual machine monitors, client-server...) That is because various tradeoffs in hardware have subtly changed with time. The human factor, however, has stayed the same. Andrei
May 21 2009
prev sibling parent "Nick Sabalausky" <a a.a> writes:
"Yigal Chripun" <yigal100 gmail.com> wrote in message 
news:gv5dpn$2oe9$1 digitalmars.com...
 I think Nemerle provies this - the constructs in Nemerle for the Macro 
 system are very simple and intuitive. you only have one extra syntax 
 feature, the <[ ]>. think of D's CTFE only much more extended in scope - 
 you write a CTFE function and compile it. (that's the Nemerle Macro 
 equivalent) than you just call it in a different file and the compiler 
 will execute this function at compile time.
 Nemerle does not need an interpreter for this since these functions are 
 compiled just like the rest of the code. Nemerle also provides compiler 
 APIs so these functions could work on AST to add/alter/remove types and 
 other constructs.

As I recall, we got onto this subject from discussing ways to combine the power of D/C++-style templates with the cross-[assembly/object] benefits of C#-style generics. I understand what you're saying here about why nemerle's macro system is like a better form of D's CTFE. But I'm unclear on how nemerle's macro system relates to the problem of achieving the best of both worlds between D/C++-style templates and C#-style generics?
May 21 2009
prev sibling parent reply Georg Wrede <georg.wrede iki.fi> writes:
Nick Sabalausky wrote:
 Suppose (purely hypothetically) that the .NET assembly system 
 were changed to allow the source for a D/C++ style of source-level template 
 to be embedded into the assembly. Then they'd be able to do D/C++ style 
 source-level template/code-generation. Right?

I assume, actually presume, that would take the better part of a decade.
 Now obviously the big problem with that is it would only be usable in
 the same language it was originally written in.

That actually depends. Done the M$ way, it would. Done properly, it would work in any language. But then, that would mean a rewrite of the entire CLR, wouldn't it?
 I suppose that might make reverse-engineering easier  [...]

I don't think that's got anything to do with it. Not at least, if they'd really do it below the language/CLR boundary.
May 21 2009
parent "Nick Sabalausky" <a a.a> writes:
"Georg Wrede" <georg.wrede iki.fi> wrote in message 
news:gv4t8t$1r49$1 digitalmars.com...
 Nick Sabalausky wrote:
 Suppose (purely hypothetically) that the .NET assembly system were 
 changed to allow the source for a D/C++ style of source-level template to 
 be embedded into the assembly. Then they'd be able to do D/C++ style 
 source-level template/code-generation. Right?

I assume, actually presume, that would take the better part of a decade.
 Now obviously the big problem with that is it would only be usable in
 the same language it was originally written in.

That actually depends. Done the M$ way, it would. Done properly, it would work in any language. But then, that would mean a rewrite of the entire CLR, wouldn't it?

Actually, I only intended that part of it as a lead-in to my idea about templates/generics working on an AST-level instead of source-level (D/C++ templates) or bytecode-level (C# generics).
May 21 2009
prev sibling next sibling parent reply dsimcha <dsimcha yahoo.com> writes:
== Quote from Yigal Chripun (yigal100 gmail.com)'s article
 Andrei Alexandrescu wrote:
 Lutger wrote:
 Andrei Alexandrescu wrote:

 ...
 What the heck do you need generics for when you have real
 templates?  To me,
 generics seem like just a lame excuse for templates.

understandably already busy implementing the using statement. Andrei

While I don't fully understand how generics work under the hood in .NET, there are some benefits to how it is done. For example, you can use runtime reflection on generic types. And the jit compiler instantiates them at runtime. They may serve a different purpose than templates: "Anders Hejlsberg: To me the best way to understand the distinction between C# generics and C++ templates is this: C# generics are really just like classes, except they have a type parameter. C++ templates are really just like macros, except they look like classes." It seems that lack of structural typing is seen as a feature: "When you think about it, constraints are a pattern matching mechanism. You want to be able to say, "This type parameter must have a constructor that takes two arguments, implement operator+, have this static method, has these two instance methods, etc." The question is, how complicated do you want this pattern matching mechanism to be? There's a whole continuum from nothing to grand pattern matching. We think it's too little to say nothing, and the grand pattern matching becomes very complicated, so we're in- between." From: http://www.artima.com/intv/genericsP.html

Oh, so Wal^H^H^Ha friend of mine I was talking to was right: there's some missing of the point point going on. The code generation aspect of templates is a blind spot of the size of Canada. Andrei

Generics and code generation are two separate and orthogonal features that where conflated together by C++. while you can do powerful stuff with templates it smells of trying to write Haskel code with the C pre-proceesor. if you want to see a clean solution to this issue look at Nemerle. essentially, their AST Macro system provides multi-level compilation. c++ templates are a horrible hack designed to ween off C programmers from using the pre-processor and the D templates provide mostly cosmetic changes to this. they do not solve the bigger design issue.

Not sure I agree. C++ templates were probably intended to be something like generics initially and became Turing-complete almost by accident. To get Turing completeness in C++ templates requires severe abuse of features and spaghetti code writing. D extends templates so that they're actually *designed* for metaprogramming, not just an implementation of generics, thus solving C++'s design problem. Mixins (to really allow code generation), CTFE (to make it easier to generate code), static if (to avoid kludges like using specialization just to get branching) and tuples (to handle variadics) make D templates useful for metaprogramming without massive kludges.
May 20 2009
parent Andrei Alexandrescu <SeeWebsiteForEmail erdani.org> writes:
dsimcha wrote:
 Not sure I agree.  C++ templates were probably intended to be something like
 generics initially and became Turing-complete almost by accident.

That is factually correct. It was quite a hubbub on the C++ standardization committee when Erwin Unruh wrote a C++ program that wrote prime numbers in error messages. See http://tinyurl.com/oqk6nl Andrei
May 20 2009
prev sibling parent BCS <ao pathlink.com> writes:
Reply to Yigal,

 D templates provide mostly cosmetic changes to this.
 

If you think D's templates are C++'s template with a few "cosmetic changes" than you aren't paying attention. A few cosmetic changes aren't going to allow 1.4MB of c++ header files to be anywhere near duplicated in 2000 LOC (Boost sprit vs dparse)
May 20 2009
prev sibling next sibling parent reply BCS <none anon.com> writes:
Hello dsimcha,

 What the heck do you need generics for when you have real templates?
 To me, generics seem like just a lame excuse for templates.
 

smaller object code? OTOH a good implementation will noice when I can fold together several template expansions
May 19 2009
next sibling parent reply dsimcha <dsimcha yahoo.com> writes:
== Quote from BCS (none anon.com)'s article
 Hello dsimcha,
 What the heck do you need generics for when you have real templates?
 To me, generics seem like just a lame excuse for templates.

together several template expansions

I understand that object file bloat with templates is at least a theoretical concern, but come on. For most programs, at least most of the ones I write, most of the memory consumption is data, and code is only a tiny fraction. Does anyone have a real world use case where object file bloat due to templates was a significant problem *and* you weren't working w/ an embedded system where you couldn't use C#/Java anyhow?
May 19 2009
parent BCS <none anon.com> writes:
Hello dsimcha,

 == Quote from BCS (none anon.com)'s article
 
 Hello dsimcha,
 
 What the heck do you need generics for when you have real templates?
 To me, generics seem like just a lame excuse for templates.
 

fold together several template expansions

theoretical concern, but come on. For most programs, at least most of the ones I write, most of the memory consumption is data, and code is only a tiny fraction. Does anyone have a real world use case where object file bloat due to templates was a significant problem *and* you weren't working w/ an embedded system where you couldn't use C#/Java anyhow?

It's not just file size, it can also cause memory and cache pressure. But to answer your question, I don't remember exactly how big the object files were but I've had DMD use up 700+ MB of ram. I /think/ it was kicking out 10+MB object files. That was running dparse with a 200 rule grammar. OTOH generics won't help with that.
May 19 2009
prev sibling parent reply Kagamin <spam here.lot> writes:
BCS Wrote:

 smaller object code? OTOH a good implementation will noice when I can fold 
 together several template expansions

That's the difference. You can't fold templates because they're binary incompatible as opposite to generics.
May 20 2009
next sibling parent reply Frits van Bommel <fvbommel REMwOVExCAPSs.nl> writes:
Kagamin wrote:
 BCS Wrote:
 
 smaller object code? OTOH a good implementation will noice when I can fold 
 together several template expansions

That's the difference. You can't fold templates because they're binary incompatible as opposite to generics.

They're not always binary-incompatible. For instance, if a template only works with pointers or references (this includes object references) to parameter types it might well contain the exact same machine code for some of the instantiations. A compiler backend or linker could recognize these cases and use a single instantiation's machine code for them. (Essentially, these are pretty much the same cases where generics would have been sufficient)
May 20 2009
parent reply Kagamin <spam here.lot> writes:
Frits van Bommel Wrote:

 That's the difference. You can't fold templates because they're binary
incompatible as opposite to generics.

They're not always binary-incompatible. For instance, if a template only works with pointers or references (this includes object references) to parameter types it might well contain the exact same machine code for some of the instantiations.

If you require that the class inherits some interface and call that interface's methods, they'll be incompatible. I'll dare to say this is the most useful variant of generic code.
May 20 2009
parent Frits van Bommel <fvbommel REMwOVExCAPSs.nl> writes:
Kagamin wrote:
 Frits van Bommel Wrote:
 
 That's the difference. You can't fold templates because they're binary
incompatible as opposite to generics.

with pointers or references (this includes object references) to parameter types it might well contain the exact same machine code for some of the instantiations.

If you require that the class inherits some interface and call that interface's methods, they'll be incompatible. I'll dare to say this is the most useful variant of generic code.

Okay, so it doesn't (usually) work for interfaces, but it'll work if the requirement is for a common base class. Or perhaps even if they happen to have a common base class that implements the interface in question.
May 20 2009
prev sibling parent reply Frits van Bommel <fvbommel REMwOVExCAPSs.nl> writes:
Denis Koroskin wrote:
 On Wed, 20 May 2009 13:09:37 +0400, Kagamin <spam here.lot> wrote:
 
 BCS Wrote:

 smaller object code? OTOH a good implementation will noice when I can  
 fold
 together several template expansions

incompatible as opposite to generics.

You can fold /some/ templates. I believe LLVM already does merging of identical functions (including templates, virtual functions etc) as a part of optimization process. Not sure about LDC, though.

LLVM has a function merging pass, but LDC doesn't run it by default at any optimization level. (You can pass -mergefunc to run it explicitly, as with any LLVM pass) It has some limitations though. Since it runs on IR, it matters what LLVM type values have. That means it might merge Templ!(int) and Templ!(uint) since int and uint are both an i32 to LLVM, but it normally wouldn't merge Templ!(int*) and Templ(short*) even if the template compiles down to "return cast(T) somefunc(cast(void*) arg);" because the types are still different (i32* vs i16*). To do the latter transformation, the pass would need to be reimplemented to run when the code is closer to machine code.
May 20 2009
parent reply bearophile <bearophileHUGS lycos.com> writes:
Frits van Bommel:
 To do the latter transformation, the pass would need to be reimplemented to
run 
 when the code is closer to machine code.

Can't this feature be asked to the LLVM developers? Bye, bearophile
May 20 2009
parent Frits van Bommel <fvbommel REMwOVExCAPSs.nl> writes:
bearophile wrote:
 Frits van Bommel:
 To do the latter transformation, the pass would need to be reimplemented to
run 
 when the code is closer to machine code.

Can't this feature be asked to the LLVM developers?

Sure, feel free to file a feature request: http://llvm.org/bugs/enter_bug.cgi?product=new-bugs
May 20 2009
prev sibling next sibling parent "Denis Koroskin" <2korden gmail.com> writes:
On Wed, 20 May 2009 13:09:37 +0400, Kagamin <spam here.lot> wrote:

 BCS Wrote:

 smaller object code? OTOH a good implementation will noice when I can  
 fold
 together several template expansions

That's the difference. You can't fold templates because they're binary incompatible as opposite to generics.

You can fold /some/ templates. I believe LLVM already does merging of identical functions (including templates, virtual functions etc) as a part of optimization process. Not sure about LDC, though.
May 20 2009
prev sibling next sibling parent reply Ary Borenszweig <ary esperanto.org.ar> writes:
dsimcha escribi:
 == Quote from Christopher Wright (dhasenan gmail.com)'s article
 Nick Sabalausky wrote:
 "Andrei Alexandrescu" <SeeWebsiteForEmail erdani.org> wrote in message
 news:gus0lu$1smj$2 digitalmars.com...

 I've repeatedly failed to figure out the coolness of C#, and would
 appreciate a few pointers. Or references. Or delegates :o).

are people who are unaware of D and are coming to C# from Java. What's "cool" about C# is that it's like a less-shitty version of Java (and *had* good tools, although the newer versions of VS are almost as much of a bloated unresponsive mess as Eclipse - Which come to think of it, makes me wonder - If Java has gotten so fast as many people claim, why is Eclipse still such a sluggish POS?). Compare C# to D though and most of the coolness fades, even though there are still a handful of things I think D could still learn from C# (but there's probably more than a handful that C# could learn from D).

that's still quite useful. And autoboxing is convenient, though not appropriate for D.

What the heck do you need generics for when you have real templates? To me, generics seem like just a lame excuse for templates.

Yesterday doob reported a bug in Descent saying "when you compile your project and it references a user library that has errors, when you click on the console to jump to the error, it doesn't work". I said to him: I never thought a user library could have errors! How did this happen to you? He replied: "I found a bug in a template in Tango". That's why generics doesn't suck: if there's something wrong in them, the compiler tells you in compile-time. In D, you get the errors only when instantiating that template. Generics might not be as powerful as templates, but once you write one that compiles, you know you will always be able to instantiate it.
May 20 2009
next sibling parent bearophile <bearophileHUGS lycos.com> writes:
Ary Borenszweig:
 That's why generics doesn't suck: if there's something wrong in them, 
 the compiler tells you in compile-time. In D, you get the errors only 
 when instantiating that template.

It's just like in dynamic languages, you need to unittest them a lot :-) So having a "static throws()" to assert that a template isn't working is very useful. Bye, bearophile
May 20 2009
prev sibling parent reply dsimcha <dsimcha yahoo.com> writes:
== Quote from Ary Borenszweig (ary esperanto.org.ar)'s article
 dsimcha escribi:
 == Quote from Christopher Wright (dhasenan gmail.com)'s article
 Nick Sabalausky wrote:
 "Andrei Alexandrescu" <SeeWebsiteForEmail erdani.org> wrote in message
 news:gus0lu$1smj$2 digitalmars.com...

 I've repeatedly failed to figure out the coolness of C#, and would
 appreciate a few pointers. Or references. Or delegates :o).

are people who are unaware of D and are coming to C# from Java. What's "cool" about C# is that it's like a less-shitty version of Java (and *had* good tools, although the newer versions of VS are almost as much of a bloated unresponsive mess as Eclipse - Which come to think of it, makes me wonder - If Java has gotten so fast as many people claim, why is Eclipse still such a sluggish POS?). Compare C# to D though and most of the coolness fades, even though there are still a handful of things I think D could still learn from C# (but there's probably more than a handful that C# could learn from D).

that's still quite useful. And autoboxing is convenient, though not appropriate for D.

What the heck do you need generics for when you have real templates? To me, generics seem like just a lame excuse for templates.

project and it references a user library that has errors, when you click on the console to jump to the error, it doesn't work". I said to him: I never thought a user library could have errors! How did this happen to you? He replied: "I found a bug in a template in Tango". That's why generics doesn't suck: if there's something wrong in them, the compiler tells you in compile-time. In D, you get the errors only when instantiating that template. Generics might not be as powerful as templates, but once you write one that compiles, you know you will always be able to instantiate it.

Yes, but there are two flaws in this argument: 1. If you are only using templates like generics, you simply use a unit test to see if it compiles. If you're not doing anything fancy and it compiles for one or two types, it will probably compile for everything that you would reasonably expect it to. 2. If you're doing something fancier, like metaprogramming, you have to just face the fact that this is non-trivial, and couldn't be done with generics anyhow. 3. As Bearophile alluded to, templates are really a clever hack to give you the flexibility of a dynamic language with the performance and compile time checking of a static language. This is done by moving the dynamism to instantiation time. Therefore, whereas in a dynamic language you pay at runtime in terms of the "here be monsters, this code may not be being used as the author intended and tested it", with templates you pay at instantiation time. However, IMHO this is orders of magnitude better than not having that flexibility at all. I personally can't figure out how people accomplish anything in static languages w/o templates. It's just too inflexible.
May 20 2009
parent Jacob Carlborg <doob me.com> writes:
dsimcha wrote:
 == Quote from Ary Borenszweig (ary esperanto.org.ar)'s article
 dsimcha escribi:
 == Quote from Christopher Wright (dhasenan gmail.com)'s article
 Nick Sabalausky wrote:
 "Andrei Alexandrescu" <SeeWebsiteForEmail erdani.org> wrote in message
 news:gus0lu$1smj$2 digitalmars.com...

 I've repeatedly failed to figure out the coolness of C#, and would
 appreciate a few pointers. Or references. Or delegates :o).

are people who are unaware of D and are coming to C# from Java. What's "cool" about C# is that it's like a less-shitty version of Java (and *had* good tools, although the newer versions of VS are almost as much of a bloated unresponsive mess as Eclipse - Which come to think of it, makes me wonder - If Java has gotten so fast as many people claim, why is Eclipse still such a sluggish POS?). Compare C# to D though and most of the coolness fades, even though there are still a handful of things I think D could still learn from C# (but there's probably more than a handful that C# could learn from D).

that's still quite useful. And autoboxing is convenient, though not appropriate for D.

generics seem like just a lame excuse for templates.

project and it references a user library that has errors, when you click on the console to jump to the error, it doesn't work". I said to him: I never thought a user library could have errors! How did this happen to you? He replied: "I found a bug in a template in Tango". That's why generics doesn't suck: if there's something wrong in them, the compiler tells you in compile-time. In D, you get the errors only when instantiating that template. Generics might not be as powerful as templates, but once you write one that compiles, you know you will always be able to instantiate it.

Yes, but there are two flaws in this argument: 1. If you are only using templates like generics, you simply use a unit test to see if it compiles. If you're not doing anything fancy and it compiles for one or two types, it will probably compile for everything that you would reasonably expect it to.

I used tango.text.xml.Document with wchar and dchar as the template type and in tango.text.xml.PullParser there were some functions that took char[] instead of T[] as the argument. http://www.dsource.org/projects/tango/ticket/1663
 2.  If you're doing something fancier, like metaprogramming, you have to just
face
 the fact that this is non-trivial, and couldn't be done with generics anyhow.
 
 3.  As Bearophile alluded to, templates are really a clever hack to give you
the
 flexibility of a dynamic language with the performance and compile time
checking
 of a static language.  This is done by moving the dynamism to instantiation
time.
  Therefore, whereas in a dynamic language you pay at runtime in terms of the
"here
 be monsters, this code may not be being used as the author intended and tested
 it", with templates you pay at instantiation time.  However, IMHO this is
orders
 of magnitude better than not having that flexibility at all.  I personally
can't
 figure out how people accomplish anything in static languages w/o templates. 
It's
 just too inflexible.

May 20 2009
prev sibling parent Christopher Wright <dhasenan gmail.com> writes:
dsimcha wrote:
 == Quote from Christopher Wright (dhasenan gmail.com)'s article
 Nick Sabalausky wrote:
 "Andrei Alexandrescu" <SeeWebsiteForEmail erdani.org> wrote in message
 news:gus0lu$1smj$2 digitalmars.com...

 I've repeatedly failed to figure out the coolness of C#, and would
 appreciate a few pointers. Or references. Or delegates :o).

are people who are unaware of D and are coming to C# from Java. What's "cool" about C# is that it's like a less-shitty version of Java (and *had* good tools, although the newer versions of VS are almost as much of a bloated unresponsive mess as Eclipse - Which come to think of it, makes me wonder - If Java has gotten so fast as many people claim, why is Eclipse still such a sluggish POS?). Compare C# to D though and most of the coolness fades, even though there are still a handful of things I think D could still learn from C# (but there's probably more than a handful that C# could learn from D).

that's still quite useful. And autoboxing is convenient, though not appropriate for D.

What the heck do you need generics for when you have real templates? To me, generics seem like just a lame excuse for templates.

Put a template in an interface. Use reflection to instantiate a template.
May 20 2009
prev sibling next sibling parent "Nick Sabalausky" <a a.a> writes:
"Steven Schveighoffer" <schveiguy yahoo.com> wrote in message 
news:op.ut4vynx5eav7ka steves.networkengines.com...
 The docs are reasonable once you figure out how  they are laid out.

I find the docs to be so slow as to be almost unusable. F*(*^*&%*& AJAX.
May 19 2009
prev sibling next sibling parent Lutger <lutger.blijdestijn gmail.com> writes:
Andrei Alexandrescu wrote:

...
 I've repeatedly failed to figure out the coolness of C#, and would 
 appreciate a few pointers. Or references. Or delegates :o).

It's not in the language. C# only has to do 'better' than C++ and Java to be cool and in that it succeeds: Besides many smaller improvements, it provides delegates / events, lambda's and true generics compared to java. Compared to C++ it provides, well, lots of the same stuff that make people prefer Java over C++. It does this while still being familiar. Take F# for example, probably a much cooler language: I suspect this is too alien for most people. The real attraction of C# is the framework and the IDE. A lot of programmers don't program in a language, but in an ecosystem where the language is just a part of it alongside the framework, toolchain and documentation.
May 19 2009
prev sibling parent Bill Baxter <wbaxter gmail.com> writes:
On Wed, May 20, 2009 at 1:09 PM, Andrei Alexandrescu
<SeeWebsiteForEmail erdani.org> wrote:
 Yigal Chripun wrote:
 I think you miss the point here.
 Generics and code generation are two separate and orthogonal features that
 where conflated together by C++.

It's kind of odd, then, that for example the Generative Programming book (http://www.generative-programming.org) chose to treat the two notions in conjunction.

Yeh, there's definitely a overlap. Orthogonal isn't quite the right word there. I'm reading a bit on C++/CLI right now, which is C++ extended to inter-operate with CLR. C++/CLI has *both* classic C++ templates and CLR generics: template<typename T> ... // all code specializations generated at compile-time (if at all) generic<typename T> ... // code generated at compiletime unconditionally, specialized at run-time. I'm not clear on exactly what happens at runtime in the generic<> case. I had been thinking it was simply that the compiler does some type checking at compile time and the VM code then just manipulates pointers to Object from there. That may be what happens in Java generics, but in CLR generics at least you can specialize on non-Object value types and that apparently does not result in everything getting boxed. So it seems like there's a little something extra going on. I think the main reason for having Generics is that they're the best anyone currently knows how to do at the IL bytecode level. Generics give you a way to define generic parameterized types that work across all the languages that target a given VM's bytecode. But that doesn't preclude any language that targets that VM from *also* implementing compile-time templates, or code generators, or AST macros at the source code level. But the problem with source-level code generation is that you then need the source code in order to use the library. I think they were trying to avoid that with C#. If you have a compiled C# assembly, then you have everything you need to use it. Period. (I think.) At any rate, a tech that requires inclusion of source code is not very interesting to Microsoft, because Microsoft doesn't generally like to let people see their source code in the first place, and they know that many of their biggest customers don't like to either. They're nervous enough about just putting de-compileable bytecode out there. --bb
May 20 2009
prev sibling next sibling parent "Steven Schveighoffer" <schveiguy yahoo.com> writes:
On Mon, 18 May 2009 12:00:02 -0400, Andrei Alexandrescu  
<SeeWebsiteForEmail erdani.org> wrote:

 I've repeatedly failed to figure out the coolness of C#, and would  
 appreciate a few pointers. Or references. Or delegates :o).

The IDE is excellent. The docs are reasonable once you figure out how they are laid out. But basically, C# is a language invented to support .NET. Try programming in any other .NET language and you find weird quirks and shoehorning (even in VB.Net). C# is MS' language, so they build in all the things that make sense to support .NET. two killer features for me: 1. .NET is usually installed or easily installed on any MS system. 2. the reflection/attributes are awesome. That being said, I prefer the syntax of D to C#, there are definitely some warts. Generics are next to useless, especially when compared to D templates. -Steve
May 18 2009
prev sibling next sibling parent reply Bill Baxter <wbaxter gmail.com> writes:
On Mon, May 18, 2009 at 12:09 PM, Robert Fraser
<fraserofthenight gmail.com> wrote:
 Steven Schveighoffer wrote:
 The IDE is excellent. =A0The docs are reasonable once you figure out how
 they are laid out.

I really don't get what's so great about VS. After using JDT (Eclipse Jav=

 I find Vs kind of lacking. IMO, MS invests a lot of resources in areas to
 sell VS to companies rather than programmers. Automatic checking against =

 models... okay, that's a cool feature, but I'd rather it could highlight =

 semantic errors without my having to click "build" or have more than 5
 refactorings or have quick-fixes for errors, or...

It's a lot nicer with Visual Assist or (from what I hear) Resharper. But it is sad that you have to pay even more money to make the thing you paid so much money for in the first place more usable. Considering things like Eclipse are free. --bb
May 18 2009
next sibling parent reply BCS <ao pathlink.com> writes:
Reply to Bill,

 But it is sad that you have to pay even
 more money to make the thing you paid so much money for in the first
 place more usable.

VS/MS/etc is a for profit ecosystem. They assume that your system and software is paid for by your boss and he's spending 10-20 time that much on your paycheck so who cares. At least that's the impression I get.
May 18 2009
parent reply grauzone <none example.net> writes:
 and the .net cil is a genious idea. The most succefull compilers are the 
 ones that recognize that there is multiple languages, multiple 
 archictectures and that there should be something in the middle. CIL 
 just leaves it in the middle code until the last minute. MS may not do 
 the best operating systems but the whole .net thing is very good in my 

And what exactly is good about byte code? It's portable? My D code is portable too. Sure, it requires recompilation, but it doesn't need a clusterfuck-VM just for running it.
 opinion and I think sun is better for there solaris than there java.

.Net is just Microsoft's Java clone, and Sun didn't invent byte code either.
May 19 2009
parent Daniel Keep <daniel.keep.lists gmail.com> writes:
grauzone wrote:
 and the .net cil is a genious idea. The most succefull compilers are
 the ones that recognize that there is multiple languages, multiple
 archictectures and that there should be something in the middle. CIL
 just leaves it in the middle code until the last minute. MS may not do
 the best operating systems but the whole .net thing is very good in my 

And what exactly is good about byte code? It's portable? My D code is portable too. Sure, it requires recompilation, but it doesn't need a clusterfuck-VM just for running it.

There's a few points here: 1. Users don't like compiling software. Hell, *I* don't like having to compile software since it invariably doesn't work first go, even when the build instructions are correct (they often aren't.) 2. A very large number of Windows developers write closed-source software. The idea of having customers obtain and compile their software scares the pants off of them. If it didn't, they wouldn't invest so much money in obfuscators. I hate to be the one to tell you this, but... MS didn't design .NET to make you happy. *ducks* -- Daniel
May 19 2009
prev sibling next sibling parent "Tim Matthews" <tim.matthews7 gmail.com> writes:
On Tue, 19 May 2009 08:56:59 +1200, BCS <ao pathlink.com> wrote:

 VS/MS/etc is a for profit ecosystem. They assume that your system and  
 software is paid for by your boss and he's spending 10-20 time that much  
 on your paycheck so who cares. At least that's the impression I get.

I think vs express editions that can be used to make great software, sell the software and not pay MS a single cent is very generous of them and the .net cil is a genious idea. The most succefull compilers are the ones that recognize that there is multiple languages, multiple archictectures and that there should be something in the middle. CIL just leaves it in the middle code until the last minute. MS may not do the best operating systems but the whole .net thing is very good in my opinion and I think sun is better for there solaris than there java.
May 19 2009
prev sibling next sibling parent "Tim Matthews" <tim.matthews7 gmail.com> writes:
On Wed, 20 May 2009 15:08:43 +1200, Daniel Keep  
<daniel.keep.lists gmail.com> wrote:

 I hate to be the one to tell you this, but... MS didn't design .NET to
 make you happy.  *ducks*

   -- Daniel

Windos is a very user orientated os and to make the user happy they try to get all devs writing code that will work on windows easily. Also IIRC java bytecode is interpreted by default but .net is jit/aot which is how my cpu should be used. I think .net is only interpreted on the .net micro framework
May 19 2009
prev sibling next sibling parent Jarrett Billingsley <jarrett.billingsley gmail.com> writes:
On Wed, May 20, 2009 at 12:26 AM, Tim Matthews <tim.matthews7 gmail.com> wr=
ote:
 On Wed, 20 May 2009 15:08:43 +1200, Daniel Keep
 <daniel.keep.lists gmail.com> wrote:

 I hate to be the one to tell you this, but... MS didn't design .NET to
 make you happy. =A0*ducks*

 =A0-- Daniel

Windos is a very user orientated os and to make the user happy they try t=

 get all devs writing code that will work on windows easily. Also IIRC jav=

 bytecode is interpreted by default but .net is jit/aot which is how my cp=

 should be used. I think .net is only interpreted on the .net micro framew=


Just, uh, wow. Please dude, read up on this stuff first.
May 19 2009
prev sibling parent "Tim Matthews" <tim.matthews7 gmail.com> writes:
On Wed, 20 May 2009 17:31:14 +1200, Jarrett Billingsley  
<jarrett.billingsley gmail.com> wrote:

 Just, uh, wow.  Please dude, read up on this stuff first.

This thread turned into a java vs .net argument. I'm sorry but I don't know the details of the JVM's just in time compiler. The virtual machine in the name plus the design goals led me to this misunderstanding "It should be interpreted, threaded, and dynamic" http://en.wikipedia.org/wiki/Java_(programming_language)#Primary_goals http://en.wikipedia.org/wiki/Comparison_of_the_Java_and_.NET_platforms
May 20 2009
prev sibling next sibling parent Christopher Wright <dhasenan gmail.com> writes:
davidl wrote:
  From a commercial basis for Walter, it may be easier to glue a C# 
 frontend against the DMD backend to create a native C# compiler.

Mono has AOT compilation. On the other hand, I've experienced more ICE per minute with Mono than with dmd. This is partially due to dmd's near monoculture and .NET's huge majority market share -- people code around dmdfe bugs, but not around Mono bugs.
May 18 2009
prev sibling parent "Steven Schveighoffer" <schveiguy yahoo.com> writes:
On Wed, 20 May 2009 23:40:54 -0400, Nick Sabalausky <a a.a> wrote:

 "Christopher Wright" <dhasenan gmail.com> wrote in message
 news:gv29vn$7a0$1 digitalmars.com...
 Nick Sabalausky wrote:
 "Christopher Wright" <dhasenan gmail.com> wrote in message
 news:gv0p4e$uvv$1 digitalmars.com...
 Nick Sabalausky wrote:
 I can see certain potential benefits to the general way C# does
 generics, but until the old (and I do mean old) issue of "There's an
 IComparable, so why the hell won't MS give us an IArithmetic so we  
 can
 actually use arithmetic operators on generic code?" gets fixed (and  
 at
 this point I'm convinced they've never had any intent of ever fixing
 that), I don't care how valid the reasoning behind C#'s general
 approach to generics is, the actual state of C#'s generics still  
 falls
 squarely into the categories of "crap" and "almost useless".

methods, and interfaces cannot specify static methods.

Then how does IComparable work?

It uses a member function instead.

And they can't do the same for arithmetic?

Keep in mind that the member method does not map to an operator. So you still have to call it directly: object.compareTo(object2); -Steve
May 21 2009