From 563a807be78bfe12e5bfbb9ff0d6da44242696c4 Mon Sep 17 00:00:00 2001
From: David Robillard <d@drobilla.net>
Date: Thu, 2 Dec 2010 06:16:29 +0000
Subject: Represent code as list structure (i.e. traditional LISP lists built
 from pairs), rather than tuple structure. Remove unused/crufty depoly stage.
 Remove cps from AST interface (but keep cps.cpp code around for later).
 Improved command line interface for compilation stages (options -T -L -S).

git-svn-id: http://svn.drobilla.net/resp/resp@277 ad02d1e2-f140-0410-9f75-f8b11f17cedd
---
 src/unify.cpp | 46 ++++++++++++++++++++++------------------------
 1 file changed, 22 insertions(+), 24 deletions(-)

(limited to 'src/unify.cpp')

diff --git a/src/unify.cpp b/src/unify.cpp
index a4ea035..9165d49 100644
--- a/src/unify.cpp
+++ b/src/unify.cpp
@@ -31,19 +31,19 @@ TEnv::buildSubst(const AType* genericT, const AType& argsT)
 	Subst subst;
 
 	// Build substitution to apply to generic type
-	const ATuple* genericProtT = (*(genericT->begin() + 1))->as<const ATuple*>();
+	const ATuple* genericProtT = genericT->list_ref(1)->as<const ATuple*>();
 	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*>();
+		const AType* callArgT    = (*a)->to<const AType*>();
 		if (callArgT->kind == AType::EXPR) {
 			assert(genericArgT->kind == AType::EXPR);
 			ATuple::const_iterator gi = genericArgT->begin();
 			ATuple::const_iterator ci = callArgT->begin();
 			for (; gi != genericArgT->end(); ++gi, ++ci) {
 				const AType* gT = (*gi)->to<const AType*>();
-				AType*       aT = (*ci)->to<AType*>();
+				const AType* aT = (*ci)->to<const AType*>();
 				if (gT && aT)
 					subst.add(gT, aT);
 			}
@@ -64,29 +64,27 @@ Constraints::constrain(TEnv& tenv, const AST* o, const AType* t)
 	push_back(Constraint(tenv.var(o), t));
 }
 
-template<typename T, typename E>
-static const T*
-substitute(const T* tup, const E* from, const E* to)
+static const AType*
+substitute(const AType* tup, const AType* from, const AType* to)
 {
 	if (!tup) return NULL;
-	T* ret = new T(*tup);
-	typename T::iterator ri = ret->begin();
-	FOREACHP(typename T::const_iterator, i, tup) {
+	TList ret;
+	FOREACHP(AType::const_iterator, i, tup) {
 		if (**i == *from) {
-			T* type = new T(*to);
+			AType* type = new AType(*to);
 			type->loc = (*i)->loc;
-			*ri++ = type;
-		} else if (static_cast<const E*>(*i) != static_cast<const E*>(to)) {
-			const T* subTup = dynamic_cast<const T*>(*i);
-			if (subTup)
-				*ri++ = const_cast<E*>(substitute(subTup, from, to));
+			ret.push_back(type);
+		} else if (*i != to) {
+			const AType* elem = (*i)->as<const AType*>();
+			if (elem->kind == AType::EXPR)
+				ret.push_back(const_cast<AType*>(substitute(elem, from, to)));
 			else
-				*ri++ = *i;
+				ret.push_back(const_cast<AType*>(elem));
 		} else {
-			++ri;
+			ret.push_back(const_cast<AType*>((*i)->as<const AType*>()));
 		}
 	}
-	return ret;
+	return ret.head;
 }
 
 /// Compose two substitutions (TAPL 22.1.1)
@@ -114,14 +112,14 @@ Constraints::replace(const AType* s, const AType* t)
 			AType* type = new AType(*t);
 			type->loc = c->first->loc;
 			c->first = type;
-		} else {
+		} else if (c->first->kind == AType::EXPR) {
 			c->first = substitute(c->first, s, t);
 		}
 		if (*c->second == *s) {
 			AType* type = new AType(*t);
 			type->loc = c->second->loc;
 			c->second = type;
-		} else {
+		} else if (c->second->kind == AType::EXPR) {
 			c->second = substitute(c->second, s, t);
 		}
 	}
@@ -150,15 +148,15 @@ unify(const Constraints& constraints)
 		AType::const_iterator si = s->begin();
 		AType::const_iterator ti = t->begin();
 		for (; si != s->end() && ti != t->end(); ++si, ++ti) {
-			AType* st = (*si)->as<AType*>();
-			AType* tt = (*ti)->as<AType*>();
+			const AType* st = (*si)->as<const AType*>();
+			const AType* tt = (*ti)->as<const AType*>();
 			if (st->kind == AType::DOTS || tt->kind == AType::DOTS)
 				return unify(cp);
 			else
 				cp.push_back(Constraint(st, tt));
 		}
-		if (   (si == s->end() && (ti == t->end() || (*ti)->as<AType*>()->kind == AType::DOTS))
-		    || (ti == t->end() && (*si)->as<AType*>()->kind == AType::DOTS))
+		if (   (si == s->end() && (ti == t->end() || (*ti)->as<const AType*>()->kind == AType::DOTS))
+		    || (ti == t->end() && (*si)->as<const AType*>()->kind == AType::DOTS))
 			return unify(cp);
 	}
 	throw Error(s->loc,
-- 
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