1 files changed, 43 insertions, 30 deletions

diff --git a/src/constrain.cpp b/src/constrain.cpp
index 2fd3fa9..982f195 100644
--- a/src/constrain.cpp
+++ b/src/constrain.cpp
@@ -51,7 +51,7 @@ void
 ATuple::constrain(TEnv& tenv, Constraints& c) const
 {
 	AType* t = tup<AType>(loc, NULL);
-	FOREACH(const_iterator, p, *this) {
+	FOREACHP(const_iterator, p, this) {
 		(*p)->constrain(tenv, c);
 		t->push_back(tenv.var(*p));
 	}
@@ -76,10 +76,12 @@ AFn::constrain(TEnv& tenv, Constraints& c) const
 		frame.push_back(make_pair(sym, tvar));
 		protT->push_back(tvar);
 	}
-	c.constrain(tenv, at(1), protT);
+
+	const_iterator i = begin() + 1;
+	c.constrain(tenv, *i, protT);
 
 	// Add internal definitions to environment frame
-	for (const_iterator i = begin() + 2; i != end(); ++i) {
+	for (++i; i != end(); ++i) {
 		const AST*  exp = *i;
 		const ADef* def = exp->to<const ADef*>();
 		if (def) {
@@ -94,10 +96,11 @@ AFn::constrain(TEnv& tenv, Constraints& c) const
 	tenv.push(frame);
 
 	c.constrain(tenv, this, tenv.var());
-	for (size_t i = 2; i < size(); ++i)
-		at(i)->constrain(tenv, c);
+	AST* exp = NULL;
+	for (i = begin() + 2; i != end(); ++i)
+		(exp = *i)->constrain(tenv, c);
 
-	AType* bodyT = tenv.var(at(size() - 1));
+	AType* bodyT = tenv.var(exp);
 	AType* fnT = tup<AType>(loc, tenv.penv.sym("Fn"), protT, bodyT, 0);
 	Object::pool.addRoot(fnT);
 
@@ -109,8 +112,8 @@ AFn::constrain(TEnv& tenv, Constraints& c) const
 void
 ACall::constrain(TEnv& tenv, Constraints& c) const
 {
-	for (size_t i = 0; i < size(); ++i)
-		at(i)->constrain(tenv, c);
+	for (const_iterator i = begin(); i != end(); ++i)
+		(*i)->constrain(tenv, c);
 
 	const AType* fnType = tenv.var(head());
 	if (fnType->kind != AType::VAR) {
@@ -120,15 +123,15 @@ ACall::constrain(TEnv& tenv, Constraints& c) const
 				|| fnType->head()->to<const ASymbol*>()->cppstr != "Fn")
 			throw Error(loc, (format("call to non-function `%1%'") % head()->str()).str());
 
-		size_t numArgs = fnType->at(1)->to<const ATuple*>()->size();
+		size_t numArgs = fnType->prot()->size();
 		THROW_IF(numArgs != size() - 1, loc,
 				(format("expected %1% arguments, got %2%") % numArgs % (size() - 1)).str());
 	}
 
 	AType* retT  = tenv.var();
 	AType* argsT = tup<AType>(loc, 0);
-	for (size_t i = 1; i < size(); ++i)
-		argsT->push_back(tenv.var(at(i)));
+	for (const_iterator i = begin() + 1; i != end(); ++i)
+		argsT->push_back(tenv.var(*i));
 
 	c.constrain(tenv, head(), tup<AType>(head()->loc, tenv.penv.sym("Fn"), argsT, retT, 0));
 	c.constrain(tenv, this, retT);
@@ -141,10 +144,10 @@ ADef::constrain(TEnv& tenv, Constraints& c) const
 	const ASymbol* sym = this->sym();
 	THROW_IF(!sym, loc, "`def' has no symbol")
 
-	AType* tvar = tenv.var(at(2));
+	AType* tvar = tenv.var(body());
 	tenv.def(sym, tvar);
-	at(2)->constrain(tenv, c);
-	c.constrain(tenv, at(1), tvar);
+	body()->constrain(tenv, c);
+	c.constrain(tenv, sym, tvar);
 	c.constrain(tenv, this, tenv.named("Nothing"));
 }
 
@@ -153,16 +156,20 @@ AIf::constrain(TEnv& tenv, Constraints& c) const
 {
 	THROW_IF(size() < 4, loc, "`if' requires at least 3 arguments");
 	THROW_IF(size() % 2 != 0, loc, "`if' missing final else clause")
-	for (size_t i = 1; i < size(); ++i)
-		at(i)->constrain(tenv, c);
+	for (const_iterator i = begin() + 1; i != end(); ++i)
+		(*i)->constrain(tenv, c);
 	AType* retT = tenv.var(this);
-	for (size_t i = 1; i < size(); i += 2) {
-		if (i == size() - 1) {
-			c.constrain(tenv, at(i), retT);
+	for (const_iterator i = begin() + 1; true; ++i) {
+		const_iterator next = i;
+		++next;
+		if (next == end()) { // final (else) expression
+			c.constrain(tenv, *i, retT);
+			break;
 		} else {
-			c.constrain(tenv, at(i), tenv.named("Bool"));
-			c.constrain(tenv, at(i+1), retT);
+			c.constrain(tenv, *i, tenv.named("Bool"));
+			c.constrain(tenv, *next, retT);
 		}
+		i = next; // jump 2 each iteration (to the next predicate)
 	}
 }
 
@@ -182,34 +189,40 @@ APrimitive::constrain(TEnv& tenv, Constraints& c) const
 	else
 		throw Error(loc, (format("unknown primitive `%1%'") % n).str());
 
-	for (size_t i = 1; i < size(); ++i)
-		at(i)->constrain(tenv, c);
+	const_iterator i = begin();
+
+	for (++i; i != end(); ++i)
+		(*i)->constrain(tenv, c);
+
+	i = begin();
 
+	AType* var = NULL;
 	switch (type) {
 	case ARITHMETIC:
 		if (size() < 3)
 			throw Error(loc, (format("`%1%' requires at least 2 arguments") % n).str());
-		for (size_t i = 1; i < size(); ++i)
-			c.constrain(tenv, at(i), tenv.var(this));
+		for (++i; i != end(); ++i)
+			c.constrain(tenv, *i, tenv.var(this));
 		break;
 	case BINARY:
 		if (size() != 3)
 			throw Error(loc, (format("`%1%' requires exactly 2 arguments") % n).str());
-		c.constrain(tenv, at(1), tenv.var(this));
-		c.constrain(tenv, at(2), tenv.var(this));
+		c.constrain(tenv, *++i, tenv.var(this));
+		c.constrain(tenv, *++i, tenv.var(this));
 		break;
 	case LOGICAL:
 		if (size() != 3)
 			throw Error(loc, (format("`%1%' requires exactly 2 arguments") % n).str());
 		c.constrain(tenv, this,  tenv.named("Bool"));
-		c.constrain(tenv, at(1), tenv.named("Bool"));
-		c.constrain(tenv, at(2), tenv.named("Bool"));
+		c.constrain(tenv, *++i, tenv.named("Bool"));
+		c.constrain(tenv, *++i, tenv.named("Bool"));
 		break;
 	case COMPARISON:
 		if (size() != 3)
 			throw Error(loc, (format("`%1%' requires exactly 2 arguments") % n).str());
+		var = tenv.var(*++i);
 		c.constrain(tenv, this, tenv.named("Bool"));
-		c.constrain(tenv, at(1), tenv.var(at(2)));
+		c.constrain(tenv, *++i, var);
 		break;
 	default:
 		throw Error(loc, (format("unknown primitive `%1%'") % n).str());