Is there something similar to C #define for its stringizer ?

Is that possible with DXL to do something like this code :

Object o // o has a real attribute named "X"
 
... // some code to set o 
 
real x = 1.
 
#define DOIT(X) \
  o . #X = X
 
DOIT(x)

This expected to be equivalent to:

Object o // o has a real attribute named "X"
 
... // some code to set o 
 
real x = 1.
 
o."x" = x

In the code above `#' is the stringizer of C preprocessor. I don't think that there is any such thing in DXL. It would actually be sometimes convenient to have the identifier of some variable into a string and vice versa.

BR,
Vincent.

PS: FYI, this string/identifier correspondence exists in a number of other languages, especially interpreted languages. For instance emacs-lisp you can play tricks like this with intern and symbol-name functions, but lisp has dynamic scope which I guess is not the case of DXL. In Linotte language you can do similar a thing as Lisp <intern>, i.e. create dynamically a variable by passing its identifier as a string. In Scilab the function exists allows to test whether a variable is existing also by passing its identifier as a string. etc...

Vincent.

SystemAdmin - Tue Feb 15 12:14:37 EST 2011

Re: Is there something similar to C #define for its stringizer ?
SystemAdmin - Tue Feb 15 12:16:46 EST 2011

Ooops..., in the example I meant that o had an attribute named "x" (in lower, not upper, case. Sorry for the confusion.

Re: Is there something similar to C #define for its stringizer ?
Mathias Mamsch - Tue Feb 15 12:44:42 EST 2011

That is a feature probably every DXL developer dreams of. DXL code macros ... Code inspection functions ... aah. Sorry! No such thing in DOORS ;-) I think DXL is not even a dynamic language by the way. As far as I know the DXL parser will translate the program to a DOORS internal laguage assembly like language (XTC?) and then execute that in a virtual machine.

However you can do a preprocessor DXL++ which will enable all those nifty syntax features, and then we can see if we get sodius to integrate it in the DXL editor ;-) I offer classes and inheritance as features for DXL++.

Regards, Mathias

Mathias Mamsch, IT-QBase GmbH, Consultant for Requirement Engineering and D00RS

Re: Is there something similar to C #define for its stringizer ?
SystemAdmin - Wed Feb 16 02:50:16 EST 2011

Mathias Mamsch - Tue Feb 15 12:44:42 EST 2011
That is a feature probably every DXL developer dreams of. DXL code macros ... Code inspection functions ... aah. Sorry! No such thing in DOORS ;-) I think DXL is not even a dynamic language by the way. As far as I know the DXL parser will translate the program to a DOORS internal laguage assembly like language (XTC?) and then execute that in a virtual machine.

However you can do a preprocessor DXL++ which will enable all those nifty syntax features, and then we can see if we get sodius to integrate it in the DXL editor ;-) I offer classes and inheritance as features for DXL++.

Regards, Mathias

Mathias Mamsch, IT-QBase GmbH, Consultant for Requirement Engineering and D00RS

Hello,

Well, rather than re-inventing the wheel there could some use of some existing multipurpose preprocessor like M4. There could be some kind of script detecting if there are some file foo.m4 and no file foo.dxl, or file foo.dxl is older than foo.m4, then run m4 on foo.m4, and if this works then run foo.dxl.

That would not be C like, but on the other hand m4 is by far more powerful than the C preprocessor is, and I guess that the developping effort would be quite light as m4 is a free software that existing on most platforms --- as it is par of the GNU project.

Vincent.

Re: Is there something similar to C #define for its stringizer ?
Mathias Mamsch - Wed Feb 16 12:55:51 EST 2011

SystemAdmin - Wed Feb 16 02:50:16 EST 2011
Hello,

Well, rather than re-inventing the wheel there could some use of some existing multipurpose preprocessor like M4. There could be some kind of script detecting if there are some file foo.m4 and no file foo.dxl, or file foo.dxl is older than foo.m4, then run m4 on foo.m4, and if this works then run foo.dxl.

That would not be C like, but on the other hand m4 is by far more powerful than the C preprocessor is, and I guess that the developping effort would be quite light as m4 is a free software that existing on most platforms --- as it is par of the GNU project.

Vincent.

Nice idea to use an existing preprocessor / templating engine / macro expansion tool. What I read from the web m4 seems to have a little awkward syntax, but there seem to be several other free alternatives. Would probably be worth to integrate that into an editor. Any ideas for special macros that would bring a productivity increase? Regards, Mathias

Mathias Mamsch, IT-QBase GmbH, Consultant for Requirement Engineering and D00RS

Re: Is there something similar to C #define for its stringizer ?
SystemAdmin - Thu Feb 17 05:53:38 EST 2011

Could you please clarify what is awkward in M4 syntax, and what other alternative you consider.

Maybe the simplest other alternative is to used the C prepropressor. But then there are potential issues. For instance space/carriage are not significant in C, while a carriage return may crate a virtual semi-colon in DXL, so I am not sure that this is not creating some issue.

Also the CPP will insert #line directives in the output (for ensuring compile errors can be tracked back to source code), I am not sure that you can deactivate this, here are the options of mingw cpp:

cpp --help
Usage: cpp.exe [options] file...
Options:
  -pass-exit-codes         Exit with highest error code from a phase
  --help                   Display this information
  --target-help            Display target specific command line options
  --help={target|optimizers|warnings|undocumented|params}[,{[^]joined|[^]separate}]
                           Display specific types of command line options
  (Use '-v --help' to display command line options of sub-processes)
  -dumpspecs               Display all of the built in spec strings
  -dumpversion             Display the version of the compiler
  -dumpmachine             Display the compiler's target processor
  -print-search-dirs       Display the directories in the compiler's search path
  -print-libgcc-file-name  Display the name of the compiler's companion library
  -print-file-name=<lib>   Display the full path to library <lib>
  -print-prog-name=<prog>  Display the full path to compiler component <prog>
  -print-multi-directory   Display the root directory for versions of libgcc
  -print-multi-lib         Display the mapping between command line options and
                           multiple library search directories
  -print-multi-os-directory Display the relative path to OS libraries
  -print-sysroot-headers-suffix Display the sysroot suffix used to find headers
  -Wa,<options>            Pass comma-separated <options> on to the assembler
  -Wp,<options>            Pass comma-separated <options> on to the preprocessor
  -Wl,<options>            Pass comma-separated <options> on to the linker
  -Xassembler <arg>        Pass <arg> on to the assembler
  -Xpreprocessor <arg>     Pass <arg> on to the preprocessor
  -Xlinker <arg>           Pass <arg> on to the linker
  -combine                 Pass multiple source files to compiler at once
  -save-temps              Do not delete intermediate files
  -pipe                    Use pipes rather than intermediate files
  -time                    Time the execution of each subprocess
  -specs=<file>            Override built-in specs with the contents of <file>
  -std=<standard>          Assume that the input sources are for <standard>
  --sysroot=<directory>    Use <directory> as the root directory for headers
                           and libraries
  -B <directory>           Add <directory> to the compiler's search paths
  -b <machine>             Run gcc for target <machine>, if installed
  -V <version>             Run gcc version number <version>, if installed
  -v                       Display the programs invoked by the compiler
  -###                     Like -v but options quoted and commands not executed
  -E                       Preprocess only; do not compile, assemble or link
  -S                       Compile only; do not assemble or link
  -c                       Compile and assemble, but do not link
  -o <file>                Place the output into <file>
  -x <language>            Specify the language of the following input files
                           Permissible languages include: c c++ assembler none
                           'none' means revert to the default behavior of
                           guessing the language based on the file's extension
 
Options starting with -g, -f, -m, -O, -W, or --param are automatically
 passed on to the various sub-processes invoked by cpp.exe.  In order to pass
 other options on to these processes the -W<letter> options must be used.
 
For bug reporting instructions, please see:
<http://www.mingw.org/bugs.shtml>.

Regards,
Vincent.

Re: Is there something similar to C #define for its stringizer ?
Mathias Mamsch - Thu Feb 17 15:58:56 EST 2011

SystemAdmin - Thu Feb 17 05:53:38 EST 2011

cpp --help
Usage: cpp.exe [options] file...
Options:
  -pass-exit-codes         Exit with highest error code from a phase
  --help                   Display this information
  --target-help            Display target specific command line options
  --help={target|optimizers|warnings|undocumented|params}[,{[^]joined|[^]separate}]
                           Display specific types of command line options
  (Use '-v --help' to display command line options of sub-processes)
  -dumpspecs               Display all of the built in spec strings
  -dumpversion             Display the version of the compiler
  -dumpmachine             Display the compiler's target processor
  -print-search-dirs       Display the directories in the compiler's search path
  -print-libgcc-file-name  Display the name of the compiler's companion library
  -print-file-name=<lib>   Display the full path to library <lib>
  -print-prog-name=<prog>  Display the full path to compiler component <prog>
  -print-multi-directory   Display the root directory for versions of libgcc
  -print-multi-lib         Display the mapping between command line options and
                           multiple library search directories
  -print-multi-os-directory Display the relative path to OS libraries
  -print-sysroot-headers-suffix Display the sysroot suffix used to find headers
  -Wa,<options>            Pass comma-separated <options> on to the assembler
  -Wp,<options>            Pass comma-separated <options> on to the preprocessor
  -Wl,<options>            Pass comma-separated <options> on to the linker
  -Xassembler <arg>        Pass <arg> on to the assembler
  -Xpreprocessor <arg>     Pass <arg> on to the preprocessor
  -Xlinker <arg>           Pass <arg> on to the linker
  -combine                 Pass multiple source files to compiler at once
  -save-temps              Do not delete intermediate files
  -pipe                    Use pipes rather than intermediate files
  -time                    Time the execution of each subprocess
  -specs=<file>            Override built-in specs with the contents of <file>
  -std=<standard>          Assume that the input sources are for <standard>
  --sysroot=<directory>    Use <directory> as the root directory for headers
                           and libraries
  -B <directory>           Add <directory> to the compiler's search paths
  -b <machine>             Run gcc for target <machine>, if installed
  -V <version>             Run gcc version number <version>, if installed
  -v                       Display the programs invoked by the compiler
  -###                     Like -v but options quoted and commands not executed
  -E                       Preprocess only; do not compile, assemble or link
  -S                       Compile only; do not assemble or link
  -c                       Compile and assemble, but do not link
  -o <file>                Place the output into <file>
  -x <language>            Specify the language of the following input files
                           Permissible languages include: c c++ assembler none
                           'none' means revert to the default behavior of
                           guessing the language based on the file's extension
 
Options starting with -g, -f, -m, -O, -W, or --param are automatically
 passed on to the various sub-processes invoked by cpp.exe.  In order to pass
 other options on to these processes the -W<letter> options must be used.
 
For bug reporting instructions, please see:
<http://www.mingw.org/bugs.shtml>.

Regards,
Vincent.

In the end the "awkwardness" of m4 is only a personal judgement from what I (only very briefly) saw. Just looking over the examples in the "notes on the m4 makro language" made me think of a mixture of perl and lisp. I for example are a pythongelist, so the first thing I looked for was a python based general preprocessor. The first thing I found was PYM. Then there are templating engines like "lua" or "cog". I know none of those - however before choosing which tool is suited, it makes sense to think about what would really be a good addition to the DXL syntax to improve productivity. Obviously the #define ... stuff would be very nice, but one could think about more. For example a better support for structs/classes. Variable argument parameter lists. More ideas? Regards, Mathias

Mathias Mamsch, IT-QBase GmbH, Consultant for Requirement Engineering and D00RS