From 59117fc8bcd610697a45c0013fc7450de2ee512f Mon Sep 17 00:00:00 2001
From: David Robillard <d@drobilla.net>
Date: Sun, 15 Mar 2009 02:27:15 +0000
Subject: Make TEnv strictly keyed by ASymbol. Prettier casting.

git-svn-id: http://svn.drobilla.net/resp/tuplr@93 ad02d1e2-f140-0410-9f75-f8b11f17cedd
---
 llvm.cpp   | 23 ++++++-----------------
 tuplr.hpp  |  7 ++++++-
 typing.cpp |  4 ++--
 3 files changed, 14 insertions(+), 20 deletions(-)

diff --git a/llvm.cpp b/llvm.cpp
index f9e045a..240cb2f 100644
--- a/llvm.cpp
+++ b/llvm.cpp
@@ -146,17 +146,6 @@ LITERAL(int32_t, "Int",   ConstantInt::get(Type::Int32Ty, val, true))
 LITERAL(float,   "Float", ConstantFP::get(Type::FloatTy, val))
 LITERAL(bool,    "Bool",  ConstantInt::get(Type::Int1Ty, val, false))
 
-template<typename T>
-T
-checked_cast(AST* ast)
-{
-	T t = dynamic_cast<T>(ast);
-	if (!t)
-		throw Error((format("internal error: `%1%' should be a `%2%'")
-				% typeid(ast).name() % typeid(T).name()).str(), ast->loc);
-	return t;
-}
-
 static Function*
 compileFunction(CEnv& cenv, const std::string& name, const Type* retT, const ATuple& protT,
 		const vector<string> argNames=vector<string>())
@@ -165,7 +154,7 @@ compileFunction(CEnv& cenv, const std::string& name, const Type* retT, const ATu
 
 	vector<const Type*> cprot;
 	for (size_t i = 0; i < protT.size(); ++i) {
-		AType* at = checked_cast<AType*>(protT.at(i));
+		AType* at = protT.at(i)->as<AType*>();
 		if (!lltype(at)) throw Error("function parameter is untyped");
 		cprot.push_back(lltype(at));
 	}
@@ -226,7 +215,7 @@ AClosure::lift(CEnv& cenv)
 	const_iterator p = prot()->begin();
 	size_t i = 0;
 	for (Function::arg_iterator a = f->arg_begin(); a != f->arg_end(); ++a, ++p)
-		cenv.def(checked_cast<ASymbol*>(*p), *p, checked_cast<AType*>(protT->at(i++)), &*a);
+		cenv.def((*p)->as<ASymbol*>(), *p, protT->at(i++)->as<AType*>(), &*a);
 
 	// Write function body
 	try {
@@ -286,7 +275,7 @@ AClosure::liftCall(CEnv& cenv, const vector<AType*>& argsT)
 	const_iterator p = prot()->begin();
 	size_t i = 0;
 	for (Function::arg_iterator a = f->arg_begin(); a != f->arg_end(); ++a, ++p)
-		cenv.def(checked_cast<ASymbol*>(*p), *p, checked_cast<AType*>(protT->at(i++)), &*a);
+		cenv.def((*p)->as<ASymbol*>(), *p, protT->at(i++)->as<AType*>(), &*a);
 
 	// Write function body
 	try {
@@ -347,7 +336,7 @@ ACall::lift(CEnv& cenv)
 	cenv.push();
 
 	for (size_t i = 1; i < size(); ++i)
-		cenv.def(checked_cast<ASymbol*>(c->prot()->at(i-1)), at(i), cenv.type(at(i)), NULL);
+		cenv.def(c->prot()->at(i-1)->as<ASymbol*>(), at(i), cenv.type(at(i)), NULL);
 
 	c->liftCall(cenv, argsT); // Lift called closure
 	cenv.pop(); // Restore environment
@@ -382,10 +371,10 @@ ACall::compile(CEnv& cenv)
 void
 ADefinition::lift(CEnv& cenv)
 {
-	if (cenv.code.lookup(checked_cast<ASymbol*>(at(1))))
+	if (cenv.code.lookup(at(1)->as<ASymbol*>()))
 		throw Error(string("`") + at(1)->str() + "' redefined", loc);
 	// Define first for recursion
-	cenv.def(checked_cast<ASymbol*>(at(1)), at(2), cenv.type(at(2)), NULL);
+	cenv.def(at(1)->as<ASymbol*>(), at(2), cenv.type(at(2)), NULL);
 	at(2)->lift(cenv);
 }
 
diff --git a/tuplr.hpp b/tuplr.hpp
index 130307e..506742a 100644
--- a/tuplr.hpp
+++ b/tuplr.hpp
@@ -153,6 +153,11 @@ struct AST {
 	virtual void constrain(TEnv& tenv, Constraints& c) const {}
 	virtual void lift(CEnv& cenv)                 {}
 	string str() const { ostringstream ss; ss << this; return ss.str(); }
+	template<typename T> T as() {
+		T t = dynamic_cast<T>(this);
+		if (!t) throw Error("internal error: bad cast", loc);
+		return t;
+	}
 	Cursor loc;
 private:
 	friend class CEnv;
@@ -448,7 +453,7 @@ struct Subst : public map<const AType*,AType*> {
 };
 
 /// Type-Time Environment
-struct TEnv : public Env<const AST*,AType*> {
+struct TEnv : public Env<const ASymbol*,AType*> {
 	TEnv(PEnv& p) : penv(p), varID(1) {}
 
 	AType* fresh(const ASymbol* sym) {
diff --git a/typing.cpp b/typing.cpp
index d6f7acc..105140e 100644
--- a/typing.cpp
+++ b/typing.cpp
@@ -110,7 +110,7 @@ AClosure::constrain(TEnv& tenv, Constraints& c) const
 		genericType = new AType(loc, tenv.penv.sym("Fn"),
 				tsubst.apply(protT), tsubst.apply(bodyT), 0);
 		tenv.genericTypes.insert(make_pair(this, genericType));
-		tenv.def(this, genericType);
+		//tenv.def(this, genericType);
 
 		tenv.pop();
 		subst = new Subst(tsubst);
@@ -141,7 +141,7 @@ ADefinition::constrain(TEnv& tenv, Constraints& c) const
 	if (!dynamic_cast<const ASymbol*>(at(1)))
 		throw Error("`def' name is not a symbol", loc);
 	AType* tvar = tenv.var(at(2));
-	tenv.def(at(1), tvar);
+	tenv.def(at(1)->as<ASymbol*>(), tvar);
 	at(2)->constrain(tenv, c);
 	c.constrain(tenv, this, tvar);
 }
-- 
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