Re: Scriptlike v0.9.4 - Perl-like interpolated strings, full examples and more.
On 2015-09-25 23:28, H. S. Teoh via Digitalmars-d-announce wrote:
It's to work around a dmd bug that doesn't allow overloads between
templates and non-templates. But I just checked, looks like that bug
may have been fixed since, so now the following overloads would work:
void writefln(string format, A...)(A args) { ... } // current
void writefln(A...)(string format, A args) { ... } // new
1. "writefln" is already a template [1]:
void writefln(Char, A...)(in Char[] fmt, A args)
2. Both of your above examples are templates
3. The easiest way to workaround that bug is to make the non-template
function a template function without arguments:
void foo()(int a);
void foo(T)(T a, T b);
But if the bug is fixed, then that's great :)
[1]
https://github.com/D-Programming-Language/phobos/blob/master/std/stdio.d#L1362
--
/Jacob Carlborg
Re: Scriptlike v0.9.4 - Perl-like interpolated strings, full examples and more.
On 09/23/2015 08:42 PM, Meta wrote: What about even just removing the syntax distinction between string mixins and template mixins? mixin "int i = 0"; mixin declareI!(); I like that idea. It it feasible? I'd always assumed the syntaxes were different because they needed to be for some sort of technical reason. But now that I look at it...maybe that could work after all?
Re: Scriptlike v0.9.4 - Perl-like interpolated strings, full examples and more.
On Friday, 25 September 2015 at 14:38:33 UTC, Nick Sabalausky
wrote:
I like that idea. It it feasible? I'd always assumed the
syntaxes were different because they needed to be for some sort
of technical reason. But now that I look at it...maybe that
could work after all?
At first glance I can't see any problem with it, other than the
fact that it makes it somewhat ambiguous whether you're mixing in
a string returned from a CTFE function or a template mixin in
some cases.
mixin template mixable()
{
int i = 0;
}
string mixable()()
{
return "int i = 0;";
}
However, this currently causes a compile time error anyway, so I
don't believe it's a problem.
//Error, two templates with the same name
mixin mixable!();
Re: Scriptlike v0.9.4 - Perl-like interpolated strings, full examples and more.
On Fri, Sep 25, 2015 at 02:14:30PM +0200, Jacob Carlborg via
Digitalmars-d-announce wrote:
> On 2015-09-25 02:15, H. S. Teoh via Digitalmars-d-announce wrote:
>
> >I wanted to work on it, but haven't actually gotten to it yet.
> >Basically, the idea is relatively simple:
> >
> > // compile-time variant
> > void writefln(string format="", A...)(A args)
> > if (format.length > 0)
> > {
> > ... // implementation here
> > }
> >
> > // runtime variant
> > void writefln(string format="", A...)(A args)
> > if (format.length == 0 && args.length > 0 &&
> > is(typeof(args[0]) == string))
> > {
> > ... // current implementation
> > }
>
> Not sure why you need to complicate it with template constraints. Just
> overload the function?
[...]
It's to work around a dmd bug that doesn't allow overloads between
templates and non-templates. But I just checked, looks like that bug
may have been fixed since, so now the following overloads would work:
void writefln(string format, A...)(A args) { ... } // current
void writefln(A...)(string format, A args) { ... } // new
T
--
Don't drink and derive. Alcohol and algebra don't mix.
Re: Scriptlike v0.9.4 - Perl-like interpolated strings, full examples and more.
On 2015-09-25 02:15, H. S. Teoh via Digitalmars-d-announce wrote:
I wanted to work on it, but haven't actually gotten to it yet.
Basically, the idea is relatively simple:
// compile-time variant
void writefln(string format="", A...)(A args)
if (format.length > 0)
{
... // implementation here
}
// runtime variant
void writefln(string format="", A...)(A args)
if (format.length == 0 && args.length > 0 &&
is(typeof(args[0]) == string))
{
... // current implementation
}
Not sure why you need to complicate it with template constraints. Just
overload the function?
--
/Jacob Carlborg
Re: Scriptlike v0.9.4 - Perl-like interpolated strings, full examples and more.
Am 23.09.2015 um 16:33 schrieb Nick Sabalausky:
(...)
void main()
{
int somevar = 42;
mixin interp;
iwriteln!("This is ${somevar}.");
int another = 17;
iwriteln!("This won't work, using ${another}.");
}
Seems like it would be too awkward and confusing to be worthwhile. :(
True, it's still far from being good. There is another possible syntax
variation:
mixin template iwriteln(string str, int line = __LINE__)
{
auto __dummy_/*~line*/ = () {
import std.stdio;
// pretend to parse the input string
write("Result: ");
write(result);
writeln();
return true;
} ();
}
void main()
{
int result = 42;
mixin iwriteln!"Result: #{result}";
}
Works only for top-level calls, but has less visual noise, so maybe it
makes sense to include that as a convenience function.
Re: Scriptlike v0.9.4 - Perl-like interpolated strings, full examples and more.
On 2015-09-23 15:59, Ben Boeckel via Digitalmars-d-announce wrote: Be aware that you will have to pay an extra lstat call for such a function so that *it* can call the right function. It certainly shouldn't replace the existing functions. Perhaps not in Phobos, but I don't see why someone using Scriptlike would care. As I understand it, the whole point of Scriptlike is convenience. -- /Jacob Carlborg
Re: Scriptlike v0.9.4 - Perl-like interpolated strings, full examples and more.
On 09/23/2015 01:44 AM, Sönke Ludwig wrote:
Am 22.09.2015 um 22:18 schrieb Nick Sabalausky:
=
String Interpolation:
=
https://github.com/Abscissa/scriptlike#string-interpolation
AFAICT, a string mixin is necessary to accomplish this in D, but
otherwise it works much like other languages:
// Output: The number 21 doubled is 42!
int num = 21;
writeln(
mixin(interp!"The number ${num} doubled is ${num * 2}!")
);
The interpolated sections are handled via std.conv.text(), so they
accept any type.
Bikeshedding requested! I'm not 100% sold on the name "interp" for this
long-term. Suggestions welcome.
An alternative idea would be to mix in a local "writeln" function, which
can then be used multiple times without syntax overhead:
mixin template interp()
{
void iwriteln(string str)()
{
// pretend that we actually parse the string ;)
write("This is ");
write(somevar);
writeln(".");
}
}
void main()
{
int somevar = 42;
mixin interp;
iwriteln!("This is ${somevar}.");
}
Yah, I think we need something like that in the stdlib. Also, we need
writefln with compile-time format string (someone was working on it but
I haven't heard about it in a while). -- Andrei
Re: Scriptlike v0.9.4 - Perl-like interpolated strings, full examples and more.
On Thu, Sep 24, 2015 at 08:00:53PM -0400, Andrei Alexandrescu via
Digitalmars-d-announce wrote:
[...]
> Yah, I think we need something like that in the stdlib. Also, we need
> writefln with compile-time format string (someone was working on it
> but I haven't heard about it in a while). -- Andrei
https://issues.dlang.org/show_bug.cgi?id=13568
I wanted to work on it, but haven't actually gotten to it yet.
Basically, the idea is relatively simple:
// compile-time variant
void writefln(string format="", A...)(A args)
if (format.length > 0)
{
... // implementation here
}
// runtime variant
void writefln(string format="", A...)(A args)
if (format.length == 0 && args.length > 0 &&
is(typeof(args[0]) == string))
{
... // current implementation
}
This will allow backward compatibility with the current writefln API,
while allowing existing code to simply transition from:
writefln("...", ...);
to:
writefln!"..."(...);
The tricky part is how to extricate the various parts of the current
implementation in order to take full advantage of compile-time format
strings, e.g., (1) don't import anything except what's necessary to
format the current format string (the current format() has to import,
e.g., std.bigint even if you never use BigInt, because it can't assume
that a runtime format string might not ask to format BigInts; this
causes the infamous format() template bloat) -- this includes allowing
format() to be pure, @nogc, etc. if your format strings never ask for
anything that requires that; (2) compile-time argument mismatch checking
(e.g., writefln!"%d"("abc") should give a compile-time error rather than
a runtime exception).
A lot of the current implementation will probably have to be overhauled
/ rewritten in order to make this work. That part unfortunately requires
a lot of time, which I don't have right now.
T
--
Creativity is not an excuse for sloppiness.
Re: Scriptlike v0.9.4 - Perl-like interpolated strings, full examples and more.
On 2015-09-23 08:32, Dmitry Olshansky wrote: Bugzilla issue with this enhancement would help a lot with this ;) And a PR would make it happen... https://issues.dlang.org/show_bug.cgi?id=15102 I'm too lazy for a PR. -- /Jacob Carlborg
Re: Scriptlike v0.9.4 - Perl-like interpolated strings, full examples and more.
On 09/23/2015 01:44 AM, Sönke Ludwig wrote:
An alternative idea would be to mix in a local "writeln" function, which
can then be used multiple times without syntax overhead:
mixin template interp()
{
void iwriteln(string str)()
{
// pretend that we actually parse the string ;)
write("This is ");
write(somevar);
writeln(".");
}
}
void main()
{
int somevar = 42;
mixin interp;
iwriteln!("This is ${somevar}.");
}
Hmm, interesting idea. I'd leave it as a string-returning function,
rather than automatically printing, but a writeln convenience wrapper is
a nice idea too.
The one problem I'm seeing with it though, is it wouldn't be able to see
symbols declared between the "mixin interp;" and any later uses of it. Ie:
void main()
{
int somevar = 42;
mixin interp;
iwriteln!("This is ${somevar}.");
int another = 17;
iwriteln!("This won't work, using ${another}.");
}
Seems like it would be too awkward and confusing to be worthwhile. :(
Re: Scriptlike v0.9.4 - Perl-like interpolated strings, full examples and more.
On 09/23/2015 02:21 AM, Jacob Carlborg wrote: Different bikeshedding: I would prefer to make the curly braces optional if it only contains a symbol. I agree. I've left that as a future enhancement for the right now. Although it shouldn't be too difficult a change. Filing it here: https://github.com/Abscissa/scriptlike/issues/23
Re: Scriptlike v0.9.4 - Perl-like interpolated strings, full examples and more.
On Wed, Sep 23, 2015 at 08:30:18 +0200, Jacob Carlborg via Digitalmars-d-announce wrote: > One thing that really bugs me in Phobos, Scriptlike seems to have the > same problem, is that there are three (!!!) different functions to > remove something from the file system. Give me just one function that > removes everything, regardless if it's a file, directory and if it's > empty or not. Be aware that you will have to pay an extra lstat call for such a function so that *it* can call the right function. It certainly shouldn't replace the existing functions. --Ben
Re: Scriptlike v0.9.4 - Perl-like interpolated strings, full examples and more.
On 09/23/2015 02:30 AM, Jacob Carlborg wrote: On 2015-09-22 22:18, Nick Sabalausky wrote: Big update to Scriptlike, v0.9.4: https://github.com/Abscissa/scriptlike Scriptlike is a library to help you write script-like programs in D. One thing that really bugs me in Phobos, Scriptlike seems to have the same problem, is that there are three (!!!) different functions to remove something from the file system. Give me just one function that removes everything, regardless if it's a file, directory and if it's empty or not. Me too. That's why this latest version adds removePath and tryRemovePath, which do exactly that ;) http://semitwist.com/scriptlike-docs/v0.9.4/scriptlike/file/extras/removePath.html http://semitwist.com/scriptlike-docs/v0.9.4/scriptlike/file/extras/tryRemovePath.html (Pardon the excess paragraph breaks on those pages. *cough* https://github.com/D-Programming-Language/dmd/pull/4745 *cough*) Of course, that does mean two *more* functions, but at least they're the only ones you need. :)
Re: Scriptlike v0.9.4 - Perl-like interpolated strings, full examples and more.
On 09/23/2015 03:18 PM, Chad Joan wrote:
This is why I argued for alternative mixin syntax in D some ... years?
... ago.
It'd be really cool to have a writefln overload that did this:
int somevar = 42;
writefln#("This is ${somevar}");
writefln#("Plus two and you get ${somevar+1}");
Which would just be shorthand for
int somevar = 42;
mixin writefln!("This is ${somevar}");
mixin writefln!("Plus two and you get ${somevar+2}");
I feel like a bit of syntax sugar could go a long way ;)
Yea, the trouble with string mixins is that they're ugly enough people
don't like to use them.
I'd argued in the past for a way to tag a CTFE-able string-returning
function as being intended for mixing-in, so you could omit the
"mixin(...)" part. But we only ever got it for template mixins. Allowing
it for string mixins was too controversial. :(
I dunno, maybe even a string mixin sugar as simple as this would be a
big help:
mixin!func(args to func here)
ie:
mixin!interp("Some string here")
But I'm guessing the ship's ling since sailed for anything like that.
Re: Scriptlike v0.9.4 - Perl-like interpolated strings, full examples and more.
On 2015-09-22 22:18, Nick Sabalausky wrote:
=
String Interpolation:
=
https://github.com/Abscissa/scriptlike#string-interpolation
AFAICT, a string mixin is necessary to accomplish this in D, but
otherwise it works much like other languages:
// Output: The number 21 doubled is 42!
int num = 21;
writeln(
mixin(interp!"The number ${num} doubled is ${num * 2}!")
);
The interpolated sections are handled via std.conv.text(), so they
accept any type.
Bikeshedding requested! I'm not 100% sold on the name "interp" for this
long-term. Suggestions welcome.
Different bikeshedding: I would prefer to make the curly braces optional
if it only contains a symbol.
--
/Jacob Carlborg
Re: Scriptlike v0.9.4 - Perl-like interpolated strings, full examples and more.
On 2015-09-22 22:18, Nick Sabalausky wrote: Big update to Scriptlike, v0.9.4: https://github.com/Abscissa/scriptlike Scriptlike is a library to help you write script-like programs in D. One thing that really bugs me in Phobos, Scriptlike seems to have the same problem, is that there are three (!!!) different functions to remove something from the file system. Give me just one function that removes everything, regardless if it's a file, directory and if it's empty or not. -- /Jacob Carlborg
Re: Scriptlike v0.9.4 - Perl-like interpolated strings, full examples and more.
On 23-Sep-2015 09:30, Jacob Carlborg wrote: On 2015-09-22 22:18, Nick Sabalausky wrote: Big update to Scriptlike, v0.9.4: https://github.com/Abscissa/scriptlike Scriptlike is a library to help you write script-like programs in D. One thing that really bugs me in Phobos, Scriptlike seems to have the same problem, is that there are three (!!!) different functions to remove something from the file system. Give me just one function that removes everything, regardless if it's a file, directory and if it's empty or not. Bugzilla issue with this enhancement would help a lot with this ;) And a PR would make it happen... -- Dmitry Olshansky
Re: Scriptlike v0.9.4 - Perl-like interpolated strings, full examples and more.
On Wednesday, 23 September 2015 at 14:33:23 UTC, Nick Sabalausky
wrote:
On 09/23/2015 01:44 AM, Sönke Ludwig wrote:
An alternative idea would be to mix in a local "writeln"
function, which
can then be used multiple times without syntax overhead:
mixin template interp()
{
void iwriteln(string str)()
{
// pretend that we actually parse the string ;)
write("This is ");
write(somevar);
writeln(".");
}
}
void main()
{
int somevar = 42;
mixin interp;
iwriteln!("This is ${somevar}.");
}
Hmm, interesting idea. I'd leave it as a string-returning
function, rather than automatically printing, but a writeln
convenience wrapper is a nice idea too.
The one problem I'm seeing with it though, is it wouldn't be
able to see symbols declared between the "mixin interp;" and
any later uses of it. Ie:
void main()
{
int somevar = 42;
mixin interp;
iwriteln!("This is ${somevar}.");
int another = 17;
iwriteln!("This won't work, using ${another}.");
}
Seems like it would be too awkward and confusing to be
worthwhile. :(
This is why I argued for alternative mixin syntax in D some ...
years? ... ago.
It'd be really cool to have a writefln overload that did this:
int somevar = 42;
writefln#("This is ${somevar}");
writefln#("Plus two and you get ${somevar+1}");
Which would just be shorthand for
int somevar = 42;
mixin writefln!("This is ${somevar}");
mixin writefln!("Plus two and you get ${somevar+2}");
I feel like a bit of syntax sugar could go a long way ;)
Re: Scriptlike v0.9.4 - Perl-like interpolated strings, full examples and more.
On Wednesday, 23 September 2015 at 19:28:03 UTC, Nick Sabalausky
wrote:
On 09/23/2015 03:18 PM, Chad Joan wrote:
This is why I argued for alternative mixin syntax in D some
... years?
... ago.
It'd be really cool to have a writefln overload that did this:
int somevar = 42;
writefln#("This is ${somevar}");
writefln#("Plus two and you get ${somevar+1}");
Which would just be shorthand for
int somevar = 42;
mixin writefln!("This is ${somevar}");
mixin writefln!("Plus two and you get ${somevar+2}");
I feel like a bit of syntax sugar could go a long way ;)
Yea, the trouble with string mixins is that they're ugly enough
people don't like to use them.
I'd argued in the past for a way to tag a CTFE-able
string-returning function as being intended for mixing-in, so
you could omit the "mixin(...)" part. But we only ever got it
for template mixins. Allowing it for string mixins was too
controversial. :(
I dunno, maybe even a string mixin sugar as simple as this
would be a big help:
mixin!func(args to func here)
ie:
mixin!interp("Some string here")
But I'm guessing the ship's ling since sailed for anything like
that.
I hope not :(
I remember when Walter originally designed mixins, he stated
something to the effect that he wanted them to be easily
greppable at all times.
I would argue that they are so centrally important that they
should be a symbol rather than a keyword. Still greppable. But
also much more useful.
Since D already has the mixin keyword, I suspect it would be more
practical to just ask people to grep for 'mixin|'
instead of just 'mixin'.
There are similar (but orthogonal) concerns with delegate
(anonymous function) nesting:
// D notation.
foo ( (x,y) {
auto z = doSomething(x+y);
return z*z;
});
vs
// Speculative notation.
foo() : (x,y) {
auto z = doSomething(x+y);
return z*z;
}
Current D notation for nesting functions reminds me of C's
notation for structs...
// C notation.
typedef struct WhatDoIPutHereFoo
{
int x,y;
} Foo;
// D notation. (Yay, consistency!)
struct Foo
{
int x,y;
}
Extra semicolon and syntax noise and such.
I'm still incredibly glad D even has delegates and mixins at this
point ;)
Re: Scriptlike v0.9.4 - Perl-like interpolated strings, full examples and more.
On Wednesday, 23 September 2015 at 19:28:03 UTC, Nick Sabalausky
wrote:
On 09/23/2015 03:18 PM, Chad Joan wrote:
This is why I argued for alternative mixin syntax in D some
... years?
... ago.
It'd be really cool to have a writefln overload that did this:
int somevar = 42;
writefln#("This is ${somevar}");
writefln#("Plus two and you get ${somevar+1}");
Which would just be shorthand for
int somevar = 42;
mixin writefln!("This is ${somevar}");
mixin writefln!("Plus two and you get ${somevar+2}");
I feel like a bit of syntax sugar could go a long way ;)
Yea, the trouble with string mixins is that they're ugly enough
people don't like to use them.
I'd argued in the past for a way to tag a CTFE-able
string-returning function as being intended for mixing-in, so
you could omit the "mixin(...)" part. But we only ever got it
for template mixins. Allowing it for string mixins was too
controversial. :(
I dunno, maybe even a string mixin sugar as simple as this
would be a big help:
mixin!func(args to func here)
ie:
mixin!interp("Some string here")
But I'm guessing the ship's ling since sailed for anything like
that.
What about even just removing the syntax distinction between
string mixins and template mixins?
mixin "int i = 0";
mixin declareI!();
While we're at it, how about optional parens for templates as
well as functions?
Scriptlike v0.9.4 - Perl-like interpolated strings, full examples and more.
Big update to Scriptlike, v0.9.4:
https://github.com/Abscissa/scriptlike
Scriptlike is a library to help you write script-like programs in D.
The two highlights in this release are string interpolation and a full
set of examples in the documentation. Also of note are the new functions
removePath and tryRemovePath which can be used to delete files (like
remove) *or* directories (like rmdirRecurse).
Full changelog:
http://semitwist.com/scriptlike/changelog.html
=
String Interpolation:
=
https://github.com/Abscissa/scriptlike#string-interpolation
AFAICT, a string mixin is necessary to accomplish this in D, but
otherwise it works much like other languages:
// Output: The number 21 doubled is 42!
int num = 21;
writeln(
mixin(interp!"The number ${num} doubled is ${num * 2}!")
);
The interpolated sections are handled via std.conv.text(), so they
accept any type.
Bikeshedding requested! I'm not 100% sold on the name "interp" for this
long-term. Suggestions welcome.
=
Examples:
=
https://github.com/Abscissa/scriptlike
https://github.com/Abscissa/scriptlike/blob/master/USAGE.md
https://github.com/Abscissa/scriptlike/tree/master/examples
The homepage/readme now provides sample code demonstrating all of
Scriptlike's various features.
The second link above demonstrates suggested practices for how to use
Scriptlike in a D-based script.
And finally, all examples are included as actual runnable programs (all
automatically tested by "dub test", to ensure continued freshness).
==
All changes in v0.9.4:
==
- Fixed: Previous release broke the unittest script when dub test
support was added.
- Fixed: In echo mode, several functions would echo the wrong "try*" or
non-"try*" version. Ex: run echoed tryRun, and tryRename echoed rename.
- Fixed: Path and buildNormalizedPathFixed now convert back/forward
slashes to native on BOTH Windows and Posix, not just on Windows.
- Fixed: Some links within changelog and API reference were pointing to
the reference docs for Scriptlike's latest version, instead of staying
within the same documentation version. This made archived docs for
previous versions difficult to navigate.
- Enhancement: #17,#20: Added usage examples to readme.
- Enhancement: Add interp for interpolated strings:
string s = mixin( interp!"Value is ${variableOrExpression}" )
- Enhancement: Add removePath/tryRemovePath for deleting a path
regardless of whether it's a file or directory. (Calls remove for files
and rmdirRecurse for directories.)
- Enhancement: Add a Path-accepting overload of escapeShellArg for the
sake of generic code.
- Enhancement: When runCollect throws, the ErrorLevelException now
includes and displays the command's output (otherwise there'd be no way
to inspect the command's output for diagnostic purposes).
- Enhancement: Greatly extended and improved set of tests.
Re: Scriptlike v0.9.4 - Perl-like interpolated strings, full examples and more.
On Wednesday, 23 September 2015 at 01:24:54 UTC, Sebastiaan Koppe
wrote:
What about:
void echo(T)()
{
writeln(mixin(interp!T));
Won't work because it won't be able to see the local variables
you want to interpolate.
Re: Scriptlike v0.9.4 - Perl-like interpolated strings, full examples and more.
On Tuesday, 22 September 2015 at 20:18:48 UTC, Nick Sabalausky
wrote:
// Output: The number 21 doubled is 42!
int num = 21;
writeln(
mixin(interp!"The number ${num} doubled is ${num * 2}!")
);
What about:
void echo(T)()
{
writeln(mixin(interp!T));
}
At least it saves some typing.
Re: Scriptlike v0.9.4 - Perl-like interpolated strings, full examples and more.
On Wednesday, 23 September 2015 at 01:45:03 UTC, Adam D. Ruppe
wrote:
On Wednesday, 23 September 2015 at 01:24:54 UTC, Sebastiaan
Koppe wrote:
What about:
void echo(T)()
{
writeln(mixin(interp!T));
Won't work because it won't be able to see the local variables
you want to interpolate.
facepalm... ofcourse...
Well, you could still get rid of the writeln.
Re: Scriptlike v0.9.4 - Perl-like interpolated strings, full examples and more.
Am 22.09.2015 um 22:18 schrieb Nick Sabalausky:
=
String Interpolation:
=
https://github.com/Abscissa/scriptlike#string-interpolation
AFAICT, a string mixin is necessary to accomplish this in D, but
otherwise it works much like other languages:
// Output: The number 21 doubled is 42!
int num = 21;
writeln(
mixin(interp!"The number ${num} doubled is ${num * 2}!")
);
The interpolated sections are handled via std.conv.text(), so they
accept any type.
Bikeshedding requested! I'm not 100% sold on the name "interp" for this
long-term. Suggestions welcome.
An alternative idea would be to mix in a local "writeln" function, which
can then be used multiple times without syntax overhead:
mixin template interp()
{
void iwriteln(string str)()
{
// pretend that we actually parse the string ;)
write("This is ");
write(somevar);
writeln(".");
}
}
void main()
{
int somevar = 42;
mixin interp;
iwriteln!("This is ${somevar}.");
}
