[Ur] Functional infix operators ?

[Gabriel Riba]

Gabriel Riba <griba2001 <at> gmail.com> writes:

> 
> ** In the definitions section:
> 
> backtick_path = `([A-Z][A-Za-z0-9_]*\.)*[a-z_][A-Za-z0-9_']*`;
> 
> ** In the rules section:
> 
> <INITIAL> {backtick_path}  => (Tokens.BACKTICK_PATH (
>                                substring (yytext, 1, size yytext -2),
>                                pos yypos, pos yypos + size yytext));
> 

This can be simplified, expressing {backtick_path} in terms of {id} and
{cid} for identifiers and module names.

Forget {backtick_path}

* In urweb.lex

** In the rules section

<INITIAL> "`" ({cid} ".")* {id} "`"  => (
                            Tokens.BACKTICK_PATH (
                                         substring (yytext,1,size yytext -2),
                                         pos yypos, pos yypos + size yytext)
                                        );

* About the new operators precedence


** I would shift them down the list below (tighter binding) the sql
operators the comparison operators (EQ NE LT LE GT GE IS) between ARROW (->)
and (CARET, PLUSPLUS) wich are concatenation operators

But this is a matter of controversial and the language designer has the last
word.
 
  %right CAND         (* this is an SQL operator *)     

+ %right COMPOSE ANDTHEN

  %nonassoc EQ NE LT LE GT GE IS
  %right ARROW

+ %right FWDAPP
+ %left REVAPP 
+ %left BACKTICK_PATH

  %right CARET PLUSPLUS