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fix(library/elaborator): bug in process_metavar_inst, and disable simplification that is negatively impacting the elaborator

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Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>
This commit is contained in:
Leonardo de Moura 2013-12-10 17:23:22 -08:00
parent 5ae71e75bd
commit 4de5f06a97
3 changed files with 25 additions and 7 deletions
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12
src/kernel/metavar.cpp
View file

@ -317,16 +317,20 @@ bool has_assigned_metavar(expr const & e, metavar_env const & menv) {
}
local_context add_lift(local_context const & lctx, unsigned s, unsigned n) {
if (n == 0) {
if (n == 0)
return lctx;
} else if (lctx) {
#if 0
// Remark: I disabled the following simplification.
// It impacts negatively the heuristics used in the elaborator.
if (lctx) {
local_entry e = head(lctx);
// Simplification rule
// lift:(s1+n1):n2 lift:s1:n1 ---> lift:s1:n1+n2
if (e.is_lift() && s == e.s() + e.n()) {
// lift:s2:n2 lift:s1:n1 ---> lift:s1:n1+n2 when s1 <= s2 <= s1 + n1
if (e.is_lift() && e.s() <= s && s <= e.s() + e.n()) {
return add_lift(tail(lctx), e.s(), e.n() + n);
}
}
#endif
return cons(mk_lift(s, n), lctx);
}

12
src/library/elaborator/elaborator.cpp
View file

@ -866,13 +866,21 @@ class elaborator::imp {
local_context lctx = metavar_lctx(a);
unsigned i = head(lctx).s();
expr t = head(lctx).v();
metavar_env & menv = m_state.m_menv;
buffer<unification_constraint> ucs;
expr b_type = m_type_inferer(b, ctx, &menv, &ucs);
for (auto uc : ucs)
m_state.m_queue.push_front(uc);
context ctx_with_i = ctx.insert_at(i, g_x_name, b_type); // must add entry for variable #i in the context
std::unique_ptr<generic_case_split> new_cs(new generic_case_split(c, m_state));
{
// Case 1
state new_state(m_state);
justification new_assumption = mk_assumption();
// add ?m[...] == #1
push_new_eq_constraint(new_state.m_queue, ctx, pop_meta_context(a), mk_var(i), new_assumption);
push_new_eq_constraint(new_state.m_queue, ctx_with_i, pop_meta_context(a), mk_var(i), new_assumption);
// add t == b (t << b)
expr new_a = t;
expr new_b = b;
@ -923,7 +931,7 @@ class elaborator::imp {
imitation = lift_free_vars(b, i, 1);
}
new_state.m_queue.push_front(c); // keep c
push_new_eq_constraint(new_state.m_queue, ctx, mk_metavar(metavar_name(a)), imitation, new_assumption);
push_new_eq_constraint(new_state.m_queue, ctx_with_i, mk_metavar(metavar_name(a)), imitation, new_assumption);
new_cs->push_back(new_state, new_assumption);
}
bool r = new_cs->next(*this);

8
src/tests/kernel/metavar.cpp
View file

@ -439,11 +439,17 @@ static void tst21() {
expr l = add_lift(add_lift(m1, 0, 1), 1, 1);
expr r = add_lift(m1, 0, 2);
std::cout << menv.get_type(l) << " " << menv.get_type(r) << "\n";
#if 0
// Leo: I disabled the lift over lift optimization since it was
// negatively impacting the heuristics
lean_assert_eq(l, r);
lean_assert_eq(add_lift(add_lift(m1, 1, 2), 3, 4),
add_lift(m1, 1, 6));
lean_assert_ne(add_lift(add_lift(m1, 1, 3), 3, 4),
lean_assert_eq(add_lift(add_lift(m1, 1, 3), 3, 4),
add_lift(m1, 1, 7));
lean_assert_ne(add_lift(add_lift(m1, 0, 3), 3, 4),
add_lift(m1, 1, 7));
#endif
}
#define _ mk_placeholder()