Ticket #274: bugtexinfo.lib

version = "$Id: bug.lib,v 1.0 2010/02/19 q$";

category = "general";
info =
" 
LIBRARY: bugtexinfo.lib, 
PURPOSE: Shows a bug with texinfo and lib2doc
AUTHOR:  Christian Gorzel, University of Muenster

OVERVIEW:
  This library demonstrates that TeX-commands have to be quoted in the 
  overview part. @*
  A polynomial is non-constant @math{\iff \deg f \geq 1}. @*
@texinfo
@tex 
  A polynomial is non-constant \quad $\iff \deg f \geq 1$.
@end tex
@end texinfo
@*
  With quoting by a backslah, the text is fine.  @*
  A polynomial is non-constant @math{\\iff \\deg f \\geq 1}.  @*
@texinfo
@tex 
  A polynomial is non-constant \\quad $\\iff \\deg f \\geq 1$.
@end tex
@end texinfo
@*
  However, in the help-string of a proc, a quoting is not needed --- there, 
  quoting gives incorrect text.  @*

  Futhermore, commands like LIB \"poly.lib\"; need a blank after LIB, otherwise
  no output will by produced.


PROCEDURES:

     is_constant(f;)  checks whether f is constant
";

// The bug is in pl2doc.pl
// TeX commands work correctly in help-sting for procs,
// since it doubles first the backslash (unless \") in texinfo and @math environment,

LIB   "poly.lib";  // here is a blank necessary:  LIB"poly.lib";  cause problems
///////////////////////////////////////////////////////////////////////////////

proc is_constant(poly f)
"USAGE: is_constant(f); f poly   
RETURN: int, 1 if f is constant, 0 otherwise  
NOTE:         A polynomial f is non-constant @math{\\iff \\deg f \\geq 1}. (with quoting) @*

  A polynomial \"f\" is non-constant @math{\iff \deg f \geq 1}. (without quoting) @*
@texinfo
@tex 
  A polynomial is non-constant \quad $\iff \deg f \geq 1$. (without quoting)
@end tex
@end texinfo
EXAMPLE: example is_constant; shows an example
"
{
  return(deg(f)<1);
}
example
{ "EXAMPLE:"; echo =2;
   ring r = 0,x,dp;
   is_constant(x+2);
   is_constant(101);
   is_constant(0);
}
///////////////////////////////////////////////////////////////////////////////

/*

pl2doc.pl   quoted in @texinfo   @math Umgebungen, um anschliessend wieder
            doppelte backslashes zu entfernen. Dieses automatische quoten
            fehlt beim info-help-string (Overview) der library.

 This is the result, if above it is written LIB"poly.lib";  without a blank.

libparse -i bugtexinfo.lib > bugtexinfo.perl
perl ./pl2doc.pl -doc -o bugtexinfo.doc bugtexinfo.perl
Bareword found where operator expected at bugtexinfo.perl line 31, near "]ERROR"
  (Might be a runaway multi-line << string starting on line 6)
        (Missing operator before ERROR?)
Bareword found where operator expected at bugtexinfo.perl line 31, near "] cannot"
        (Missing operator before cannot?)
String found where operator expected at bugtexinfo.perl line 31, near "character ''"
        (Do you need to predeclare character?)
Bareword found where operator expected at bugtexinfo.perl line 31, near "'' in"
        (Missing operator before in?)
Bareword found where operator expected at bugtexinfo.perl line 31, near "1080979772 to"
        (Missing operator before to?)
syntax error at bugtexinfo.perl line 31, near "]ERROR occured"
Compilation failed in require at ./pl2doc.pl line 37.
make: *** [bugtexinfo.doc] Fehler 9

Put some remarks in STYLEGUIDE4libdocs
*/