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author | David Robillard <d@drobilla.net> | 2009-06-28 23:29:27 +0000 |
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committer | David Robillard <d@drobilla.net> | 2009-06-28 23:29:27 +0000 |
commit | 2d925912c38c2557ac853fb1b6de5fd6e5d4c5b5 (patch) | |
tree | 2cba1e1d747218b1e9b1c55926e135cf21c8e586 /unify.cpp | |
parent | 84274ac380968df9fb49bcbf6f3d494536d7a548 (diff) | |
download | resp-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.cpp | 94 |
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()); - } -} - |