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digitalmars.D.learn - String interpolation

reply tired_eyes <pastuhov85 gmail.com> writes:
Hi,
The only example of string interpolation I've found so far is on 
Rosetta Code:

void main() {
     import std.stdio, std.string;

     "Mary had a %s lamb.".format("little").writeln;
     "Mary had a %2$s %1$s lamb.".format("little", 
"white").writeln;
}

Is this a "proper" way of string interpolation in D? This looks a 
little clumsy. Are there any better approaches? Quick skimming 
through the docs didn't give anything.
Nov 10 2015
next sibling parent wobbles <grogan.colin gmail.com> writes:
On Tuesday, 10 November 2015 at 10:21:32 UTC, tired_eyes wrote:
 Hi,
 The only example of string interpolation I've found so far is 
 on Rosetta Code:

 void main() {
     import std.stdio, std.string;

     "Mary had a %s lamb.".format("little").writeln;
     "Mary had a %2$s %1$s lamb.".format("little", 
 "white").writeln;
 }

 Is this a "proper" way of string interpolation in D? This looks 
 a little clumsy. Are there any better approaches? Quick 
 skimming through the docs didn't give anything.
Whats clumsy about it? If it's the style (excessive use of UFCS), I'd have to agree with you. Could easily have been written as: format("Mary had a %s lamb", "little"); which I personally think is more readable...
Nov 10 2015
prev sibling parent reply Tobias Pankrath <tobias pankrath.net> writes:
On Tuesday, 10 November 2015 at 10:21:32 UTC, tired_eyes wrote:
 Hi,
 The only example of string interpolation I've found so far is 
 on Rosetta Code:

 void main() {
     import std.stdio, std.string;

     "Mary had a %s lamb.".format("little").writeln;
     "Mary had a %2$s %1$s lamb.".format("little", 
 "white").writeln;
 }

 Is this a "proper" way of string interpolation in D? This looks 
 a little clumsy. Are there any better approaches? Quick 
 skimming through the docs didn't give anything.
std.string.format and std.format are the standard options. What are you missing?
Nov 10 2015
parent reply tired_eyes <pastuhov85 gmail.com> writes:
On Tuesday, 10 November 2015 at 10:33:30 UTC, Tobias Pankrath 
wrote:
 On Tuesday, 10 November 2015 at 10:21:32 UTC, tired_eyes wrote:
 Hi,
 The only example of string interpolation I've found so far is 
 on Rosetta Code:

 void main() {
     import std.stdio, std.string;

     "Mary had a %s lamb.".format("little").writeln;
     "Mary had a %2$s %1$s lamb.".format("little", 
 "white").writeln;
 }

 Is this a "proper" way of string interpolation in D? This 
 looks a little clumsy. Are there any better approaches? Quick 
 skimming through the docs didn't give anything.
std.string.format and std.format are the standard options. What are you missing?
Ruby: a = 1 b = 4 puts "The number #{a} is less than #{b}" PHP: $a = 1; $b = 4; echo "The number $a is less than $b"; D: ???
Nov 10 2015
next sibling parent reply wobbles <grogan.colin gmail.com> writes:
On Tuesday, 10 November 2015 at 10:41:52 UTC, tired_eyes wrote:
 On Tuesday, 10 November 2015 at 10:33:30 UTC, Tobias Pankrath 
 wrote:
 On Tuesday, 10 November 2015 at 10:21:32 UTC, tired_eyes wrote:
 [...]
std.string.format and std.format are the standard options. What are you missing?
Ruby: a = 1 b = 4 puts "The number #{a} is less than #{b}" PHP: $a = 1; $b = 4; echo "The number $a is less than $b"; D: ???
int a = 1; int b = 4; writefln("The number %s is less than %s", a, b);
Nov 10 2015
parent tcak <1ltkrs+3wyh1ow7kzn1k sharklasers.com> writes:
On Tuesday, 10 November 2015 at 11:22:56 UTC, wobbles wrote:
 On Tuesday, 10 November 2015 at 10:41:52 UTC, tired_eyes wrote:
 On Tuesday, 10 November 2015 at 10:33:30 UTC, Tobias Pankrath 
 wrote:
 On Tuesday, 10 November 2015 at 10:21:32 UTC, tired_eyes 
 wrote:
 [...]
std.string.format and std.format are the standard options. What are you missing?
Ruby: a = 1 b = 4 puts "The number #{a} is less than #{b}" PHP: $a = 1; $b = 4; echo "The number $a is less than $b"; D: ???
int a = 1; int b = 4; writefln("The number %s is less than %s", a, b);
D: int a = 1; int b = 4; writeln("The number ", a, " is less than ", b);
Nov 10 2015
prev sibling parent reply TheFlyingFiddle <kurtyan student.chalmers.se> writes:
On Tuesday, 10 November 2015 at 10:41:52 UTC, tired_eyes wrote:
 On Tuesday, 10 November 2015 at 10:33:30 UTC, Tobias Pankrath 
 wrote:
 Ruby:
 a = 1
 b = 4
 puts "The number #{a} is less than #{b}"

 PHP:
 $a = 1;
 $b = 4;
 echo "The number $a is less than $b";

 D:
 ???
int a = 1, b = 4; writefln("The number %s is less than %s", a, b); You can't do it the ruby / perl / php way in D. It could be possible if we had AST macros in the language but as it stands now it's not possible to do that. the closest you could get is something like this: string s = aliasFormat!("The number $a is less than $b", a, b); or aliasWrite!("The number $a is less than $b", a, b); Not really recommended though as these would end up creating lots of template bloat.
Nov 10 2015
next sibling parent tired_eyes <pastuhov85 gmail.com> writes:
On Tuesday, 10 November 2015 at 11:29:32 UTC, TheFlyingFiddle 
wrote:
 On Tuesday, 10 November 2015 at 10:41:52 UTC, tired_eyes wrote:
 On Tuesday, 10 November 2015 at 10:33:30 UTC, Tobias Pankrath 
 wrote:
 Ruby:
 a = 1
 b = 4
 puts "The number #{a} is less than #{b}"

 PHP:
 $a = 1;
 $b = 4;
 echo "The number $a is less than $b";

 D:
 ???
int a = 1, b = 4; writefln("The number %s is less than %s", a, b); You can't do it the ruby / perl / php way in D. It could be possible if we had AST macros in the language but as it stands now it's not possible to do that. the closest you could get is something like this: string s = aliasFormat!("The number $a is less than $b", a, b); or aliasWrite!("The number $a is less than $b", a, b); Not really recommended though as these would end up creating lots of template bloat.
Thank everybody for the answers. I know about writefln, but I was hoping I just overlooked some simpler way.
Nov 10 2015
prev sibling parent reply =?UTF-8?B?TcOhcmNpbw==?= Martins <marcioapm gmail.com> writes:
On Tuesday, 10 November 2015 at 11:29:32 UTC, TheFlyingFiddle 
wrote:
 On Tuesday, 10 November 2015 at 10:41:52 UTC, tired_eyes wrote:
 On Tuesday, 10 November 2015 at 10:33:30 UTC, Tobias Pankrath 
 wrote:
 Ruby:
 a = 1
 b = 4
 puts "The number #{a} is less than #{b}"

 PHP:
 $a = 1;
 $b = 4;
 echo "The number $a is less than $b";

 D:
 ???
int a = 1, b = 4; writefln("The number %s is less than %s", a, b); You can't do it the ruby / perl / php way in D. It could be possible if we had AST macros in the language but as it stands now it's not possible to do that. the closest you could get is something like this: string s = aliasFormat!("The number $a is less than $b", a, b); or aliasWrite!("The number $a is less than $b", a, b); Not really recommended though as these would end up creating lots of template bloat.!
You could perhaps do it with a mixin instead of AST macros: int a = 10; int b = 20; writeln(mixin(interp!"The number #{a} is less than #{b}")); One thing that would make this a lot more elegant would be the ability to instantiate mixins in templates. For example: template interp(X) { alias interp = mixin(interpGenCode!X); } writeln(interp!"The number #{a} is less than #{b}"); Quite pleasant syntax this way :) Not sure if it's feasible to do this on the language side.
Nov 10 2015
parent Andrea Fontana <nospam example.com> writes:
On Tuesday, 10 November 2015 at 12:40:07 UTC, Márcio Martins 
wrote:
 writeln(interp!"The number #{a} is less than #{b}");

 Quite pleasant syntax this way :)
 Not sure if it's feasible to do this on the language side.
Yes. Here a (stupid!) proof of concept: http://dpaste.dzfl.pl/74b1a4e3c8c6
Nov 10 2015