[help-texinfo] html: playing with the style

[Akim Demaille]

Hi all,

Bison has recently gained colored diagnostics, like GCC does.  I would like

to document that and show examples of this.  I would like to do that in PDF,

but I don't think it is possible, and probably not desirable.  I would like

to do it in HTML, but then I have a bunch of problems on how to do it.

When I try something like this:

@ifhtml
@macro color{name, text}
@html
<b style="color:\name\">\text\</b>
@end html
@end macro
@end ifhtml

@ifnothtml
@macro color{name, text}
\text\
@end macro
@end ifnothtml

@example
$ @kbd{bison -Wmidrule-value mid.y}
mid.y:2.6-13: @color{purple, warning}: unset value: $$
    2 | exp: @color{purple, @{ a(); @}} "b" @{ $$ = c(); @} @{ d(); @} "e" @{ f = $1; @};
      |      @color{purple, ^~~~~~~~}
@end group
@end example

it fails with an error:

/Users/akim/src/gnu/bison/doc/bison.texi:4307: warning: @html should only appear at the beginning of a line (possibly involving @color)
/Users/akim/src/gnu/bison/doc/bison.texi:4307: superfluous argument to @end html: : unset value: $$ (possibly involving @color)
/Users/akim/src/gnu/bison/doc/bison.texi:4308: warning: @html should only appear at the beginning of a line (possibly involving @color)
/Users/akim/src/gnu/bison/doc/bison.texi:4308: superfluous argument to @end html:  "b" @{ $$ = c(); @} @{ d(); @} "e" @{ f = $1; @}; (possibly involving @color)
/Users/akim/src/gnu/bison/doc/bison.texi:4309: warning: @html should only appear at the beginning of a line (possibly involving @color)

If I add an empty lime

@ifhtml
@macro color{name, text}
@html
<b style="color:\name\">\text\</b>
@end html

@end macro
@end ifhtml

than the output is broken:

I'm afraid that the image will be removed by the mailing list, so let me describe the result: the bold and the color are there, but the layout is as follows:

mid.y:2.6-13: warning

: unset value: $$

    2 | exp: 

{ a(); }

 "b" { $$ = c(); } { d(); } "e" { f = $1; };

      |      

^~~~~~~~

instead of

mid.y:2.6-13: warning: unset value: $$

    2 | exp: { a(); }  "b" { $$ = c(); } { d(); } "e" { f = $1; };

      |      ^~~~~~~~

What can I do?

Thanks!