Move TEnv::buildSubst to unify.cpp.

git-svn-id: http://svn.drobilla.net/resp/tuplr@212 ad02d1e2-f140-0410-9f75-f8b11f17cedd

1 files changed, 34 insertions, 0 deletions

diff --git a/src/unify.cpp b/src/unify.cpp
index 74e35fd..eebd75c 100644
--- a/src/unify.cpp
+++ b/src/unify.cpp
@@ -22,6 +22,40 @@
 #include <set>
 #include "tuplr.hpp"
 
+/** Build a type substitution for calling a generic function type
+ * with a specific set of argument types
+ */
+Subst
+TEnv::buildSubst(AType* genericT, const AType& argsT)
+{
+	Subst subst;
+
+	// Build substitution to apply to generic type
+	const ATuple* genericProtT = genericT->at(1)->as<const ATuple*>();
+	assert(argsT.size() == genericProtT->size());
+	ATuple::const_iterator g = genericProtT->begin();
+	AType::const_iterator  a = argsT.begin();
+	for (; a != argsT.end(); ++a, ++g) {
+		const AType* genericArgT = (*g)->to<const AType*>();
+		AType*       callArgT    = (*a)->to<AType*>();
+		if (callArgT->kind == AType::EXPR) {
+			assert(genericArgT->kind == AType::EXPR);
+			assert(callArgT->size() == genericArgT->size());
+			for (size_t i = 0; i < callArgT->size(); ++i) {
+				const AType* gT = genericArgT->at(i)->to<const AType*>();
+				AType*       aT = callArgT->at(i)->to<AType*>();
+				if (gT && aT)
+					subst.add(gT, aT);
+			}
+		} else {
+			subst.add(genericArgT, callArgT);
+		}
+	}
+
+	return subst;
+}
+
+
 void
 Constraints::constrain(TEnv& tenv, const AST* o, AType* t)
 {