Fix if type checking for arc style if.

git-svn-id: http://svn.drobilla.net/resp/tuplr@68 ad02d1e2-f140-0410-9f75-f8b11f17cedd

1 files changed, 12 insertions, 6 deletions

diff --git a/typing.cpp b/typing.cpp
index c9febda..5e419fd 100644
--- a/typing.cpp
+++ b/typing.cpp
@@ -59,8 +59,7 @@ ASTCall::constrain(TEnv& tenv) const
 void
 ASTDefinition::constrain(TEnv& tenv) const
 {
-	if (size() != 3)
-		throw Error("`def' requires exactly 2 arguments", exp.loc);
+	if (size() != 3) throw Error("`def' requires exactly 2 arguments", exp.loc);
 	if (!dynamic_cast<const ASTSymbol*>(at(1)))
 		throw Error("`def' name is not a symbol", exp.loc);
 	FOREACH(const_iterator, p, *this)
@@ -73,12 +72,19 @@ ASTDefinition::constrain(TEnv& tenv) const
 void
 ASTIf::constrain(TEnv& tenv) const
 {
+	if (size() < 3)      throw Error("`if' requires exactly 3 arguments", exp.loc);
+	if (size() % 2 != 0) throw Error("`if' missing final else clause", exp.loc);
 	FOREACH(const_iterator, p, *this)
 		(*p)->constrain(tenv);
-	AType* tvar = tenv.type(this);
-	tenv.constrain(at(1), tenv.named("Bool"));
-	tenv.constrain(at(2), tvar);
-	tenv.constrain(at(3), tvar);
+	AType* retT = tenv.type(this);
+	for (size_t i = 1; i < size(); i += 2) {
+		if (i == size() - 1) {
+			tenv.constrain(at(i), retT);
+		} else {
+			tenv.constrain(at(i), tenv.named("Bool"));
+			tenv.constrain(at(i+1), retT);
+		}
+	}
 }
 
 void