7.4 Prolog Code Generation

Prolog code generation takes as argument the environment generated by the type-checker and produces Prolog clauses that are put as an annotation (pl_code) to the source specification. These clauses feed three requirements of the Typol implementation: a types data-base used by the Typol type-checker, dynamic type-checking and prolog to VTP conversion and dynamic type-checking.

Here is the Prolog code generated for the previous example:

%$lang(phylum)
'$L'('Phy').
%$lang(operator,Lang::phylum)
'$L'('f', '$TYPOL$l_id'('$TYPOL$id'('L'), 
                        '$TYPOL$id'('Phy'))).
'$L'('id', '$TYPOL$l_id'('$TYPOL$id'('L'), 
                         '$TYPOL$id'('Phy'))).
%$lang(operator, sons_type, name)
'$L'(
   'f',
   '$TYPOL$type_s'(
      '$TYPOL$l_id'('$TYPOL$id'('L'), '$TYPOL$id'('Phy')),
      '$TYPOL$type_s'('nil')), '$L$f').
'$L'('id', '$TYPOL$id'('string'), '$L$id').
%$lang$phylum(scheme)
delay '$L$Phy'(_X) if 'var'(_X).
'$L$Phy'('$L$f'(_)).
'$L$Phy'('$L$id'(_)).
%$lang$op(arity,lang,op)
'$L$f'(1, 'L', 'f').
'$L$id'('string', 'L', 'id').