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digitalmars.D - How simple is D for a compiler?

reply Marcel Meyer <meyerm-news01 fs.tum.de> writes:
Hello together,

after lurking around a little bit, I'm asking myself the following: is
creating a D compiler (still) a relative easy task or is it getting too big
for a small hobby-project?

As far as I understand, one of the goals of D is beeing easily parseable
etc. to make it easier for a compiler. Now, creating a fundamental C
compiler for one specific architecture is something a quite small project
can do (like tinycc.org). On the other side there are the C++ compilers -
are there meanwhile compilers who support the whole C++ standard ;-) ? But
where is D?

F.ex. I'm concerned about things like putting the regular expression into
the language itself mentioned here and there on the newsgroups. This
instead of using libs would make creating a new compiler harder. Don't take
this post as a vote against the regexps or sth. like that. I'm simply too
uninformed to have a true opinion *g*. But is simplicity not only for the
developers but also for the compiler still a design goal? If yes, could
someone give a subjective classification?


BTW: Will 1.0 be really a stable specification on which a long-term project
can be based upon or will this just mean "I'm advanced enough so you can
work with me and now we start adding shiny features"?


Hopefully I'm not too bothersome with my rookie questions :-).

Thank you very much for reading and please excuse my bumpy english.

M
Feb 18 2006
next sibling parent "Walter Bright" <newshound digitalmars.com> writes:
"Marcel Meyer" <meyerm-news01 fs.tum.de> wrote in message 
news:dt7m22$2h41$1 digitaldaemon.com...

 after lurking around a little bit, I'm asking myself the following: is
 creating a D compiler (still) a relative easy task or is it getting too 
 big
 for a small hobby-project?
 As far as I understand, one of the goals of D is beeing easily parseable
 etc. to make it easier for a compiler. Now, creating a fundamental C
 compiler for one specific architecture is something a quite small project
 can do (like tinycc.org). On the other side there are the C++ compilers -
 are there meanwhile compilers who support the whole C++ standard ;-) ? But
 where is D?


D remains an easy to lex and easy to parse language. The semantic code is 
getting more complex. So it's not a hobby project, but it's not remotely as 
complex as a C++ compiler. It's probably about on par with a C compiler (the 
C preprocessor is remarkably complicated for something that should be so 
simple).


 F.ex. I'm concerned about things like putting the regular expression into
 the language itself mentioned here and there on the newsgroups. This
 instead of using libs would make creating a new compiler harder. Don't 
 take
 this post as a vote against the regexps or sth. like that. I'm simply too
 uninformed to have a true opinion *g*. But is simplicity not only for the
 developers but also for the compiler still a design goal? If yes, could
 someone give a subjective classification?


Regex is complicated, but that won't matter, for the simple reason that one 
can just plug in one of many existing regex implementations (including 
std.regexp!) to handle that part.


 BTW: Will 1.0 be really a stable specification on which a long-term 
 project
 can be based upon or will this just mean "I'm advanced enough so you can
 work with me and now we start adding shiny features"?


I don't see any problem with using D now for a long term project.
Feb 18 2006
prev sibling next sibling parent reply Thomas Kuehne <thomas-dloop kuehne.cn> writes:
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Marcel Meyer schrieb am 2006-02-18:

 Hello together,

 after lurking around a little bit, I'm asking myself the following: is
 creating a D compiler (still) a relative easy task or is it getting too big
 for a small hobby-project?

 As far as I understand, one of the goals of D is beeing easily parseable
 etc. to make it easier for a compiler. Now, creating a fundamental C
 compiler for one specific architecture is something a quite small project
 can do (like tinycc.org). On the other side there are the C++ compilers -
 are there meanwhile compilers who support the whole C++ standard ;-) ? But
 where is D?


Frontend: Writing a parser for D is a joy.
(About a year a go I wrote a parser for and in D with ca. 200LOC.)


 F.ex. I'm concerned about things like putting the regular expression into
 the language itself mentioned here and there on the newsgroups. This
 instead of using libs would make creating a new compiler harder.


Middleware: Much more straight forward than C++ but not trivial.
Do a diff between the source of DMD-0.146 and DMD-0.147 to see, that
regular expressions are almost exclusively  syntactic sugar for accessing the
lib.


 Don't take
 this post as a vote against the regexps or sth. like that. I'm simply too
 uninformed to have a true opinion *g*. But is simplicity not only for the
 developers but also for the compiler still a design goal? If yes, could
 someone give a subjective classification?


Let's find the balance between:
1) capabilities and restrains
2) simplicity and syntactic sugar
3) compiler implementation, runtime implementation and language usage

;)

Thomas


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Feb 18 2006
parent reply Bruno Medeiros <daiphoenixNO SPAMlycos.com> writes:
Thomas Kuehne wrote:

 
 Frontend: Writing a parser for D is a joy.
 (About a year a go I wrote a parser for and in D with ca. 200LOC.)
 


A parser in 200 LoC? Surely you meant a lexer? Or perhaps it's the 200 
LoC figure that is incorrect?


-- 
Bruno Medeiros - CS/E student
"Certain aspects of D are a pathway to many abilities some consider to 
be... unnatural."
Feb 24 2006
next sibling parent kellywilson nowhere.com writes:
In article <dtn7bk$2b9a$1 digitaldaemon.com>, Bruno Medeiros says...

Thomas Kuehne wrote:

 
 Frontend: Writing a parser for D is a joy.
 (About a year a go I wrote a parser for and in D with ca. 200LOC.)
 


A parser in 200 LoC? Surely you meant a lexer? Or perhaps it's the 200 
LoC figure that is incorrect?


I would tend to agree here Bruno. Just the parse.c file supplied with dmd's
frontend is ~4700 LOC. The grammar file alone for my (incomplete) parser is
~1100. The Flex file is about 400 though, so maybe Thomas hand wrote the lexer
in 200? Maybe a typo and he meant 2000?

My two cents,
Kelly Wilson
Feb 24 2006
prev sibling parent Thomas Kuehne <thomas-dloop kuehne.cn> writes:
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Bruno Medeiros schrieb am 2006-02-24:

 Thomas Kuehne wrote:

 
 Frontend: Writing a parser for D is a joy.
 (About a year a go I wrote a parser for and in D with ca. 200LOC.)
 


 A parser in 200 LoC? Surely you meant a lexer? Or perhaps it's the 200 
 LoC figure that is incorrect?


It is something inbetween. e.g. I was interrested in symbol resolution but
didn't care about templates.

Thomas


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Feb 24 2006
prev sibling parent Marco Matthies <mcm-news moinmarco.de> writes:
Marcel Meyer wrote:

 after lurking around a little bit, I'm asking myself the following: is
 creating a D compiler (still) a relative easy task or is it getting too big
 for a small hobby-project?


You might want to check out llvm ( http://llvm.org/ ) to use as a 
compiler middle-end/back-end, this would leave you with lexing, parsing 
and transforming to llvm-assembly.

Marco
Feb 18 2006