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fix(library/unifier): bugs exposed by recent changes

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Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>
This commit is contained in:
Leonardo de Moura 2014-07-23 17:31:07 -07:00
parent 71afb83fcd
commit 314c0822de
1 changed files with 25 additions and 16 deletions
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35
src/library/unifier.cpp
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@ -29,6 +29,16 @@ static name g_unifier_max_steps {"unifier", "max_steps"};
RegisterUnsignedOption(g_unifier_max_steps, LEAN_DEFAULT_UNIFIER_MAX_STEPS, "(unifier) maximum number of steps");
unsigned get_unifier_max_steps(options const & opts) { return opts.get_unsigned(g_unifier_max_steps, LEAN_DEFAULT_UNIFIER_MAX_STEPS); }
/** \brief Return true iff \c [begin_locals, end_locals) contains \c local */
template<typename It> bool contains_local(expr const & local, It const & begin_locals, It const & end_locals) {
return std::any_of(begin_locals, end_locals, [&](expr const & l) { return mlocal_name(local) == mlocal_name(l); });
}
/** \brief Return true iff \c locals contains \c local */
bool contains_local(expr const & local, buffer<expr> const & locals) {
return contains_local(local, locals.begin(), locals.end());
}
// If \c e is a metavariable ?m or a term of the form (?m l_1 ... l_n) where
// l_1 ... l_n are distinct local variables, then return ?m, and store l_1 ... l_n in args.
// Otherwise return none.
@ -37,7 +47,7 @@ optional<expr> is_simple_meta(expr const & e, buffer<expr> & args) {
if (!is_metavar(m))
return none_expr();
for (auto it = args.begin(); it != args.end(); it++) {
if (!is_local(*it) || std::find(args.begin(), it, *it) != it)
if (!is_local(*it) || contains_local(*it, args.begin(), it))
return none_expr();
}
return some_expr(m);
@ -48,11 +58,6 @@ bool is_simple_meta(expr const & e) {
return (bool)is_simple_meta(e, args); // NOLINT
}
/** \brief Return true iff \c locals contains \c local */
bool contains_local(expr const & local, buffer<expr> const & locals) {
return std::any_of(locals.begin(), locals.end(), [&](expr const & l) { return mlocal_name(local) == mlocal_name(l); });
}
// Return true if all local constants in \c e are in locals
bool context_check(expr const & e, buffer<expr> const & locals) {
bool failed = false;
@ -1194,11 +1199,14 @@ struct unifier_fn {
// if rhs is not local, then we only add projections for the nonlocal arguments of lhs
buffer<constraint> cs;
if (auto new_mtype = ensure_sufficient_args(mtype, margs, cs, j)) {
cs.push_back(mk_eq_cnstr(marg, rhs, j));
// Remark: we should not use mk_eq_cnstr(marg, rhs, j) since is_def_eq may be able to reduce them.
// The unifier assumes the eq constraints are reduced.
if (is_def_eq(marg, rhs, j, cs)) {
expr v = mk_lambda_for(*new_mtype, mk_var(vidx));
cs.push_back(mk_eq_cnstr(m, v, j));
alts.push_back(to_list(cs.begin(), cs.end()));
}
}
} else if (is_local(marg) && is_local(rhs) && mlocal_name(marg) == mlocal_name(rhs)) {
// if the argument is local, and rhs is equal to it, then we also add a projection
buffer<constraint> cs;
@ -1301,7 +1309,7 @@ struct unifier_fn {
lean_assert(!m_subst.is_assigned(mr));
unsigned i = 0;
for (; i < lhs_args.size(); i++)
if (lhs_args[i] != rhs_args[i])
if (mlocal_name(lhs_args[i]) != mlocal_name(rhs_args[i]))
break;
if (i == lhs_args.size())
return assign(ml, mr, c.get_justification());
@ -1339,19 +1347,20 @@ struct unifier_fn {
return process_plugin_constraint(c);
} else {
lean_assert(is_eq_cnstr(c));
if (is_delta_cnstr(c))
if (is_delta_cnstr(c)) {
return process_delta(c);
else if (modified)
} else if (modified) {
return is_def_eq(cnstr_lhs_expr(c), cnstr_rhs_expr(c), c.get_justification());
else if (is_flex_rigid(c))
} else if (is_flex_rigid(c)) {
return process_flex_rigid(c);
else if (is_flex_flex(c))
} else if (is_flex_flex(c)) {
return process_flex_flex(c);
else
} else {
return process_plugin_constraint(c);
}
}
}
}
/** \brief Return true if unifier may be able to produce more solutions */
bool more_solutions() const {