add optimizations for generic bimap,

add bimap instances for standard generic types to compiler

frontend/syntax.dcl

@@ -530,24 +530,25 @@ NoGlobalIndex :== {gi_module=NoIndex,gi_index=NoIndex}
 	,	tdi_gen_rep 		:: !Optional GenericTypeRep
 	}
 
-// AA..
 // type structure is used to specialize a generic to a type
 :: GenTypeStruct 
 	= GTSAppCons TypeKind [GenTypeStruct]
 	| GTSAppVar TypeVar [GenTypeStruct] 
 	| GTSVar TypeVar
-	| GTSArrow GenTypeStruct GenTypeStruct	// needed for simplifying bimaps
-	| GTSAppConsBimapKindConst				// needed for simplifying bimaps
  	| GTSCons DefinedSymbol GenTypeStruct
  	| GTSField DefinedSymbol GenTypeStruct
  	| GTSObject DefinedSymbol GenTypeStruct
  	| GTSE
+	| GTSArrow GenTypeStruct GenTypeStruct		// for optimizing bimaps
+	| GTSAppConsBimapKindConst					// for optimizing bimaps
+	| GTSAppBimap TypeKind [GenTypeStruct]		// for optimizing bimaps
+	| GTSPair !GenTypeStruct !GenTypeStruct		// for optimizing bimaps
+	| GTSEither !GenTypeStruct !GenTypeStruct	// for optimizing bimaps
  
 :: GenericTypeRep = 
 	{ gtr_type :: GenTypeStruct		// generic structure type
 	, gtr_iso  :: DefinedSymbol		// the conversion isomorphism
 	}
-// ..AA
 
 ::	TypeDefInfos :== {# .{# TypeDefInfo}}