Destructuring (i.e. working `match').

git-svn-id: http://svn.drobilla.net/resp/resp@374 ad02d1e2-f140-0410-9f75-f8b11f17cedd

1 files changed, 11 insertions, 1 deletions

diff --git a/src/constrain.cpp b/src/constrain.cpp
index a4a1ad3..78accf6 100644
--- a/src/constrain.cpp
+++ b/src/constrain.cpp
@@ -241,6 +241,8 @@ constrain_match(TEnv& tenv, Constraints& c, const ATuple* call) throw(Error)
 		THROW_IF(!pattern, exp->loc, "pattern expression expected");
 		const ASymbol* name = (*pattern->begin())->to_symbol();
 		THROW_IF(!name, (*pattern->begin())->loc, "pattern does not start with a symbol");
+		THROW_IF(!tenv.ref(name), name->loc,
+		         (format("undefined constructor `%1%'") % name->sym()).str());
 
 		const AST* consT = *tenv.ref(name);
 
@@ -251,8 +253,16 @@ constrain_match(TEnv& tenv, Constraints& c, const ATuple* call) throw(Error)
 
 		THROW_IF(i == call->end(), pattern->loc, "missing pattern body");
 		const AST* body = *i++;
+
+		TEnv::Frame frame;
+		ATuple::const_iterator ti = consT->as_tuple()->iter_at(2);
+		for (ATuple::const_iterator pi = pattern->iter_at(1); pi != pattern->end(); ++pi)
+			frame.push_back(make_pair((*pi)->as_symbol()->sym(), *ti++));
+
+		tenv.push(frame);
 		resp_constrain(tenv, c, body);
-		c.constrain(tenv, body, retT); 
+		c.constrain(tenv, body, retT);
+		tenv.pop();
 	}
 	c.constrain(tenv, call, retT);
 	c.constrain(tenv, matchee, matcheeT);