factory-constructor is a function [BUGGY]

since there was a findall we use 'from' to generate all inputs,
but this way it could contain duplicates. the right solution is
to have a predicate listing (once) each HB generated constant.

Author: gares

HB/common/database.elpi

@@ -231,6 +231,15 @@ pred findall-mixin-src i:term, o:list mixinname.
 findall-mixin-src T ML :-
   std.map {std.findall (mixin-src T M_ V_)} mixin-src_mixin ML.
 
+func findall-factory-constructor -> list prop.
+findall-factory-constructor L :-
+  std.map {std.findall (findall-factory-constructor.aux _)} findall-factory-constructor.make L.
+pred findall-factory-constructor.aux o:prop.
+findall-factory-constructor.aux (factory-constructor F C) :-
+  from F _ _, factory-constructor F C.
+func findall-factory-constructor.make prop -> prop.
+findall-factory-constructor.make (findall-factory-constructor.aux P) P.
+
 pred findall-local-canonical o:list constant.
 findall-local-canonical CL :-
   std.map {std.findall (local-canonical C_)} local-canonical-gref CL.

HB/howto.elpi

@@ -104,7 +104,7 @@ type fdp factoryname -> list mixinname -> list mixinname -> factory_deps_prov.
 % get all available factories in the above type
 pred list_factories o:list factory_deps_prov.
 list_factories FL :-
-  std.map-filter {std.findall (factory-constructor _ _)} list_factories.aux FL.
+  std.map-filter {findall-factory-constructor} list_factories.aux FL.
 pred list_factories.aux i:prop, o:howto.private.factory_deps_prov.
 list_factories.aux (factory-constructor F _) (fdp F DML PML) :-
   gref-deps F FD,

HB/structures.v

@@ -141,7 +141,7 @@ factory-alias->gref GR _ (error Msg) :- !,
 
 % [factory-constructor F K] means K is a constructor for
 % the factory F.
-pred factory-constructor o:factoryname, o:gref.
+func factory-constructor factoryname -> gref.
 
 % [factory-nparams F N] says that F has N parameters
 func factory-nparams factoryname -> int.