aboutsummaryrefslogtreecommitdiffstats
path: root/unify.cpp
diff options
context:
space:
mode:
authorDavid Robillard <d@drobilla.net>2009-06-28 23:29:27 +0000
committerDavid Robillard <d@drobilla.net>2009-06-28 23:29:27 +0000
commit2d925912c38c2557ac853fb1b6de5fd6e5d4c5b5 (patch)
tree2cba1e1d747218b1e9b1c55926e135cf21c8e586 /unify.cpp
parent84274ac380968df9fb49bcbf6f3d494536d7a548 (diff)
downloadresp-2d925912c38c2557ac853fb1b6de5fd6e5d4c5b5.tar.gz
resp-2d925912c38c2557ac853fb1b6de5fd6e5d4c5b5.tar.bz2
resp-2d925912c38c2557ac853fb1b6de5fd6e5d4c5b5.zip
Move code into src directory.
git-svn-id: http://svn.drobilla.net/resp/tuplr@160 ad02d1e2-f140-0410-9f75-f8b11f17cedd
Diffstat (limited to 'unify.cpp')
-rw-r--r--unify.cpp94
1 files changed, 0 insertions, 94 deletions
diff --git a/unify.cpp b/unify.cpp
deleted file mode 100644
index 2a8e6a0..0000000
--- a/unify.cpp
+++ /dev/null
@@ -1,94 +0,0 @@
-/* Tuplr Unification
- * Copyright (C) 2008-2009 David Robillard <dave@drobilla.net>
- *
- * Tuplr is free software: you can redistribute it and/or modify it under
- * the terms of the GNU Affero General Public License as published by the
- * Free Software Foundation, either version 3 of the License, or (at your
- * option) any later version.
- *
- * Tuplr is distributed in the hope that it will be useful, but WITHOUT
- * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
- * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Affero General
- * Public License for more details.
- *
- * You should have received a copy of the GNU Affero General Public License
- * along with Tuplr. If not, see <http://www.gnu.org/licenses/>.
- */
-
-#include <set>
-#include "tuplr.hpp"
-
-/***************************************************************************
- * Type Inference/Substitution *
- ***************************************************************************/
-
-static void
-substitute(ATuple* tup, const AST* from, AST* to)
-{
- if (!tup) return;
- for (size_t i = 0; i < tup->size(); ++i)
- if (*tup->at(i) == *from)
- tup->at(i) = to;
- else if (tup->at(i) != to)
- substitute(tup->at(i)->to<ATuple*>(), from, to);
-}
-
-Subst
-Subst::compose(const Subst& delta, const Subst& gamma) // TAPL 22.1.1
-{
- Subst r;
- for (Subst::const_iterator g = gamma.begin(); g != gamma.end(); ++g) {
- Subst::const_iterator d = delta.find(g->second);
- r.add(g->first, ((d != delta.end()) ? d : g)->second);
- }
- for (Subst::const_iterator d = delta.begin(); d != delta.end(); ++d) {
- if (gamma.find(d->first) == gamma.end())
- r.add(d->first, d->second);
- }
- return r;
-}
-
-void
-substConstraints(Constraints& constraints, AType* s, AType* t)
-{
- for (Constraints::iterator c = constraints.begin(); c != constraints.end();) {
- Constraints::iterator next = c; ++next;
- if (*c->first == *s) c->first = t;
- if (*c->second == *s) c->second = t;
- substitute(c->first, s, t);
- substitute(c->second, s, t);
- c = next;
- }
-}
-
-Subst
-TEnv::unify(const Constraints& constraints) // TAPL 22.4
-{
- if (constraints.empty()) return Subst();
- AType* s = constraints.begin()->first;
- AType* t = constraints.begin()->second;
- Constraints cp = constraints;
- cp.erase(cp.begin());
-
- if (*s == *t) {
- return unify(cp);
- } else if (s->var() && !t->contains(s)) {
- substConstraints(cp, s, t);
- return Subst::compose(unify(cp), Subst(s, t));
- } else if (t->var() && !s->contains(t)) {
- substConstraints(cp, t, s);
- return Subst::compose(unify(cp), Subst(t, s));
- } else if (s->kind == AType::EXPR && s->kind == t->kind && s->size() == t->size()) {
- for (size_t i = 0; i < s->size(); ++i) {
- AType* si = s->at(i)->to<AType*>();
- AType* ti = t->at(i)->to<AType*>();
- if (si && ti)
- cp.push_back(Constraint(si, ti, si->loc));
- }
- return unify(cp);
- } else {
- throw Error(s->loc ? s->loc : t->loc,
- (format("type is `%1%' but should be `%2%'") % s->str() % t->str()).str());
- }
-}
-