Re: i18n for yacc backend messages

[Hans Aberg]

At 16:38 +0200 2005/04/18, Akim Demaille wrote:
>  > Would you mind enlighten me as to how %printer works? -- It seems to
>  > not be documented.
>
> %printer { how to print $$ } SYMBOLS
>
> e.g. in C++
>
> %printer { debug_stream () << *$$; } "string" "identifier"
> %printer { debug_stream () << $$; }  "integer"

If I look a bit into the output parser code, how error messages are 
written, then yyerror expects a full string. It might be too 
intrusive to change it accepting a stream instead. So it seems that 
one needs a command telling how to "stringize", or express (to 
"express" is opposite of to "parse") the token. For example:
%stringize { how to stringize $$ } "string" "identifier"

Then the %printer might use that, if the string value is somehow 
available via a symbol. E.g., in C++
%printer { debug_stream () << $$$ }
would generate a default printing rule, if $$$ represents the string 
value of the token at hand. (There is a tricky thing, if one admits a 
default printing rule, namely, if $$$ appears in its body, the 
default rule should only be defined for those tokens which has a 
%stringize definition.)

Otherwise, how and when is the defined %printer invoked for a particular token?
--
  Hans Aberg