www.digitalmars.com         C & C++   DMDScript  

digitalmars.D.bugs - [Issue 1301] New: CTFE fails for ImportExpressions

reply d-bugmail puremagic.com writes:
http://d.puremagic.com/issues/show_bug.cgi?id=1301

           Summary: CTFE fails for ImportExpressions
           Product: D
           Version: 1.017
          Platform: PC
        OS/Version: Windows
            Status: NEW
          Severity: major
          Priority: P2
         Component: DMD
        AssignedTo: bugzilla digitalmars.com
        ReportedBy: samukha voliacable.com


I believe this should to work, as 'path' is known at compile time:

char[] foo(char[] path)
{
    char[] t = import(path); //Error: file name argument must be a string, not
(path)

    return "";
}

void main(char[][] args)
{
   mixin(foo("template"));
}


--
Jun 30 2007
next sibling parent d-bugmail puremagic.com writes:
http://d.puremagic.com/issues/show_bug.cgi?id=1301


fvbommel wxs.nl changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|NEW                         |RESOLVED
         Resolution|                            |INVALID





Functions to be used in CTFE must still be compilable as normal functions.
Yours doesn't meet that criterion. Try something like:
---
char[] foo(char[] path)()
{
    char[] t = import(path); //Error: file name argument must be a string, not
(path)

    return "";
}

void main(char[][] args)
{
   mixin(foo!("template"));
}
---


--
Jun 30 2007
prev sibling parent reply d-bugmail puremagic.com writes:
http://d.puremagic.com/issues/show_bug.cgi?id=1301






Oops. Thanks for pointing that out.


--
Jun 30 2007
parent reply Chris Nicholson-Sauls <ibisbasenji gmail.com> writes:
d-bugmail puremagic.com wrote:

 http://d.puremagic.com/issues/show_bug.cgi?id=1301
 
 
 
 
 

 Oops. Thanks for pointing that out.
 
 


One thing I think should work is hiding the import() in a template, and 
sending that value off to the CTF.

template T_Import (char[] file) {
   const T_Import = import(file);
}

template T_Foo (char[] file) {
   const T_Foo = `foo("`~T_Import!(file)~`")` ;
}

char[] foo (char[] data) {
   // ...
}

void main (char[][] args) {
   mixin(T_Foo!("template"));
}

I've used something similar to preload image and font data in an SDL 
based program.  It does work -- and the extra T_Import template 
maintains one copy of a given file being embedded.  (Otherwise fonts at 
least would sometimes result in two or three copies.  Bad bad disc 
usage, that.)

-- Chris Nicholson-Sauls
Jun 30 2007
parent Max Samukha <samukha voliacable.com.removethis> writes:
On Sat, 30 Jun 2007 13:00:44 -0500, Chris Nicholson-Sauls
<ibisbasenji gmail.com> wrote:


One thing I think should work is hiding the import() in a template, and 
sending that value off to the CTF.

template T_Import (char[] file) {
   const T_Import = import(file);
}

template T_Foo (char[] file) {
   const T_Foo = `foo("`~T_Import!(file)~`")` ;
}

char[] foo (char[] data) {
   // ...
}

void main (char[][] args) {
   mixin(T_Foo!("template"));
}

I've used something similar to preload image and font data in an SDL 
based program.  It does work -- and the extra T_Import template 
maintains one copy of a given file being embedded.  (Otherwise fonts at 
least would sometimes result in two or three copies.  Bad bad disc 
usage, that.)

-- Chris Nicholson-Sauls


Thanks for the idea.
Jul 02 2007