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refactor(library/unifier): make it easier to add new options to the unifier

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Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>
This commit is contained in:
Leonardo de Moura 2014-08-20 17:30:08 -07:00
parent 0450e81392
commit f5987b7bda
7 changed files with 79 additions and 65 deletions
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2
src/frontends/lean/elaborator.cpp
View file

@ -1114,7 +1114,7 @@ public:
lazy_list<substitution> solve(constraint_seq const & cs) {
buffer<constraint> tmp;
cs.linearize(tmp);
return unify(env(), tmp.size(), tmp.data(), m_ngen.mk_child(), true, ios().get_options());
return unify(env(), tmp.size(), tmp.data(), m_ngen.mk_child(), unifier_config(ios().get_options(), true));
}
static void collect_metavars(expr const & e, buffer<expr> & mvars) {

3
src/library/tactic/apply_tactic.cpp
View file

@ -120,7 +120,8 @@ proof_state_seq apply_tactic_core(environment const & env, io_state const & ios,
}
}
list<expr> meta_lst = to_list(metas.begin(), metas.end());
lazy_list<substitution> substs = unify(env, t, e_t, ngen.mk_child(), relax_main_opaque, s.get_subst(), ios.get_options());
lazy_list<substitution> substs = unify(env, t, e_t, ngen.mk_child(), relax_main_opaque, s.get_subst(),
unifier_config(ios.get_options()));
return map2<proof_state>(substs, [=](substitution const & subst) -> proof_state {
name_generator new_ngen(ngen);
type_checker tc(env, new_ngen.mk_child());

84
src/library/unifier.cpp
View file

@ -27,13 +27,48 @@ Author: Leonardo de Moura
#include "library/unifier_plugin.h"
#include "library/kernel_bindings.h"
#ifndef LEAN_DEFAULT_UNIFIER_MAX_STEPS
#define LEAN_DEFAULT_UNIFIER_MAX_STEPS 20000
#endif
#ifndef LEAN_DEFAULT_UNIFIER_COMPUTATION
#define LEAN_DEFAULT_UNIFIER_COMPUTATION true
#endif
#ifndef LEAN_DEFAULT_UNIFIER_EXPENSIVE_CLASSES
#define LEAN_DEFAULT_UNIFIER_EXPENSIVE_CLASSES false
#endif
namespace lean {
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); }
static name g_unifier_expensive {"unifier", "expensive"};
RegisterBoolOption(g_unifier_expensive, LEAN_DEFAULT_UNIFIER_EXPENSIVE, "(unifier) enable/disable expensive (and more complete) procedure");
bool get_unifier_expensive(options const & opts) { return opts.get_bool(g_unifier_expensive, LEAN_DEFAULT_UNIFIER_EXPENSIVE); }
static name g_unifier_computation {"unifier", "computation"};
RegisterBoolOption(g_unifier_computation, LEAN_DEFAULT_UNIFIER_COMPUTATION,
"(unifier) case-split on reduction/computational steps when solving flex-rigid constraints");
bool get_unifier_computation(options const & opts) { return opts.get_bool(g_unifier_computation, LEAN_DEFAULT_UNIFIER_COMPUTATION); }
static name g_unifier_expensive_classes {"unifier", "expensive_classes"};
RegisterBoolOption(g_unifier_expensive_classes, LEAN_DEFAULT_UNIFIER_EXPENSIVE_CLASSES,
"(unifier) use \"full\" higher-order unification when solving class instances");
bool get_unifier_expensive_classes(options const & opts) {
return opts.get_bool(g_unifier_expensive_classes, LEAN_DEFAULT_UNIFIER_EXPENSIVE_CLASSES);
}
unifier_config::unifier_config(bool use_exceptions):
m_use_exceptions(use_exceptions),
m_max_steps(LEAN_DEFAULT_UNIFIER_MAX_STEPS),
m_computation(LEAN_DEFAULT_UNIFIER_COMPUTATION),
m_expensive_classes(LEAN_DEFAULT_UNIFIER_EXPENSIVE_CLASSES) {
}
unifier_config::unifier_config(options const & o, bool use_exceptions):
m_use_exceptions(use_exceptions),
m_max_steps(get_unifier_max_steps(o)),
m_computation(get_unifier_computation(o)),
m_expensive_classes(get_unifier_expensive_classes(o)) {
}
// 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.
@ -256,10 +291,8 @@ struct unifier_fn {
owned_map m_owned_map; // mapping from metavariable name m to delay factor of the choice constraint that owns m
unifier_plugin m_plugin;
type_checker_ptr m_tc[2];
bool m_use_exception; //!< True if we should throw an exception when there are no more solutions.
unsigned m_max_steps;
unifier_config m_config;
unsigned m_num_steps;
bool m_expensive;
bool m_pattern; //!< If true, then only higher-order (pattern) matching is used
bool m_first; //!< True if we still have to generate the first solution.
unsigned m_next_assumption_idx; //!< Next assumption index.
@ -348,9 +381,9 @@ struct unifier_fn {
unifier_fn(environment const & env, unsigned num_cs, constraint const * cs,
name_generator const & ngen, substitution const & s,
bool use_exception, unsigned max_steps, bool expensive):
unifier_config const & cfg):
m_env(env), m_ngen(ngen), m_subst(s), m_plugin(get_unifier_plugin(env)),
m_use_exception(use_exception), m_max_steps(max_steps), m_num_steps(0), m_expensive(expensive), m_pattern(false) {
m_config(cfg), m_num_steps(0), m_pattern(false) {
m_tc[0] = mk_type_checker_with_hints(env, m_ngen.mk_child(), false);
m_tc[1] = mk_type_checker_with_hints(env, m_ngen.mk_child(), true);
m_next_assumption_idx = 0;
@ -363,8 +396,8 @@ struct unifier_fn {
void check_system() {
check_interrupted();
if (m_num_steps > m_max_steps)
throw exception(sstream() << "unifier maximum number of steps (" << m_max_steps << ") exceeded, " <<
if (m_num_steps > m_config.m_max_steps)
throw exception(sstream() << "unifier maximum number of steps (" << m_config.m_max_steps << ") exceeded, " <<
"the maximum number of steps can be increased by setting the option unifier.max_steps " <<
"(remark: the unifier uses higher order unification and unification-hints, which may trigger non-termination");
m_num_steps++;
@ -967,7 +1000,7 @@ struct unifier_fn {
optional<substitution> failure() {
lean_assert(in_conflict());
if (m_use_exception)
if (m_config.m_use_exceptions)
throw unifier_exception(*m_conflict, m_subst);
else
return optional<substitution>();
@ -1805,7 +1838,7 @@ struct unifier_fn {
lean_assert(!m_cnstrs.empty());
auto const * p = m_cnstrs.min();
unsigned cidx = p->second;
if (!m_expensive && cidx >= get_group_first_index(cnstr_group::ClassInstance))
if (!m_config.m_expensive_classes && cidx >= get_group_first_index(cnstr_group::ClassInstance))
m_pattern = true; // use only higher-order (pattern) matching after we start processing class-instance constraints
constraint c = p->first;
// std::cout << "process_next: " << c << "\n";
@ -1907,21 +1940,16 @@ lazy_list<substitution> unify(std::shared_ptr<unifier_fn> u) {
}
lazy_list<substitution> unify(environment const & env, unsigned num_cs, constraint const * cs, name_generator const & ngen,
bool use_exception, unsigned max_steps, bool expensive) {
return unify(std::make_shared<unifier_fn>(env, num_cs, cs, ngen, substitution(), use_exception, max_steps, expensive));
}
lazy_list<substitution> unify(environment const & env, unsigned num_cs, constraint const * cs, name_generator const & ngen,
bool use_exception, options const & o) {
return unify(env, num_cs, cs, ngen, use_exception, get_unifier_max_steps(o), get_unifier_expensive(o));
unifier_config const & cfg) {
return unify(std::make_shared<unifier_fn>(env, num_cs, cs, ngen, substitution(), cfg));
}
lazy_list<substitution> unify(environment const & env, expr const & lhs, expr const & rhs, name_generator const & ngen,
bool relax, substitution const & s, unsigned max_steps, bool expensive) {
bool relax, substitution const & s, unifier_config const & cfg) {
substitution new_s = s;
expr _lhs = new_s.instantiate(lhs);
expr _rhs = new_s.instantiate(rhs);
auto u = std::make_shared<unifier_fn>(env, 0, nullptr, ngen, new_s, false, max_steps, expensive);
auto u = std::make_shared<unifier_fn>(env, 0, nullptr, ngen, new_s, cfg);
constraint_seq cs;
if (!u->m_tc[relax]->is_def_eq(_lhs, _rhs, justification(), cs) || !u->process_constraints(cs)) {
return lazy_list<substitution>();
@ -1930,11 +1958,6 @@ lazy_list<substitution> unify(environment const & env, expr const & lhs, expr co
}
}
lazy_list<substitution> unify(environment const & env, expr const & lhs, expr const & rhs, name_generator const & ngen,
bool relax, substitution const & s, options const & o) {
return unify(env, lhs, rhs, ngen, relax, s, get_unifier_max_steps(o), get_unifier_expensive(o));
}
static int unify_simple(lua_State * L) {
int nargs = lua_gettop(L);
unify_status r;
@ -2055,18 +2078,19 @@ static int unify(lua_State * L) {
environment const & env = to_environment(L, 1);
if (is_expr(L, 2)) {
if (nargs == 7)
r = unify(env, to_expr(L, 2), to_expr(L, 3), to_name_generator(L, 4), lua_toboolean(L, 5), to_substitution(L, 6), to_options(L, 7));
r = unify(env, to_expr(L, 2), to_expr(L, 3), to_name_generator(L, 4), lua_toboolean(L, 5), to_substitution(L, 6),
unifier_config(to_options(L, 7)));
else if (nargs == 6)
r = unify(env, to_expr(L, 2), to_expr(L, 3), to_name_generator(L, 4), lua_toboolean(L, 5), to_substitution(L, 6), options());
r = unify(env, to_expr(L, 2), to_expr(L, 3), to_name_generator(L, 4), lua_toboolean(L, 5), to_substitution(L, 6));
else
r = unify(env, to_expr(L, 2), to_expr(L, 3), to_name_generator(L, 4), lua_toboolean(L, 5));
} else {
buffer<constraint> cs;
to_constraint_buffer(L, 2, cs);
if (nargs == 4)
r = unify(env, cs.size(), cs.data(), to_name_generator(L, 3), false, to_options(L, 4));
r = unify(env, cs.size(), cs.data(), to_name_generator(L, 3), unifier_config(to_options(L, 4)));
else
r = unify(env, cs.size(), cs.data(), to_name_generator(L, 3), false, options());
r = unify(env, cs.size(), cs.data(), to_name_generator(L, 3));
}
return push_substitution_seq_it(L, r);
}

29
src/library/unifier.h
View file

@ -15,17 +15,9 @@ Author: Leonardo de Moura
#include "kernel/environment.h"
#include "kernel/metavar.h"
#ifndef LEAN_DEFAULT_UNIFIER_MAX_STEPS
#define LEAN_DEFAULT_UNIFIER_MAX_STEPS 20000
#endif
#ifndef LEAN_DEFAULT_UNIFIER_EXPENSIVE
#define LEAN_DEFAULT_UNIFIER_EXPENSIVE false
#endif
namespace lean {
unsigned get_unifier_max_steps(options const & opts);
bool get_unifier_unfold_opaque(options const & opts);
bool get_unifier_computation(options const & opts);
bool is_simple_meta(expr const & e);
expr mk_aux_metavar_for(name_generator & ngen, expr const & t);
@ -40,16 +32,19 @@ unify_status unify_simple(substitution & s, expr const & lhs, expr const & rhs,
unify_status unify_simple(substitution & s, level const & lhs, level const & rhs, justification const & j);
unify_status unify_simple(substitution & s, constraint const & c);
struct unifier_config {
bool m_use_exceptions;
unsigned m_max_steps;
bool m_computation;
bool m_expensive_classes;
unifier_config(bool use_exceptions = false);
explicit unifier_config(options const & o, bool use_exceptions = false);
};
lazy_list<substitution> unify(environment const & env, unsigned num_cs, constraint const * cs, name_generator const & ngen,
bool use_exception = true, unsigned max_steps = LEAN_DEFAULT_UNIFIER_MAX_STEPS,
bool expensive = LEAN_DEFAULT_UNIFIER_EXPENSIVE);
lazy_list<substitution> unify(environment const & env, unsigned num_cs, constraint const * cs, name_generator const & ngen,
bool use_exception, options const & o);
unifier_config const & c = unifier_config());
lazy_list<substitution> unify(environment const & env, expr const & lhs, expr const & rhs, name_generator const & ngen, bool relax_main_opaque,
substitution const & s = substitution(), unsigned max_steps = LEAN_DEFAULT_UNIFIER_MAX_STEPS,
bool expensive = LEAN_DEFAULT_UNIFIER_MAX_STEPS);
lazy_list<substitution> unify(environment const & env, expr const & lhs, expr const & rhs, name_generator const & ngen,
bool relax_main_opaque, substitution const & s, options const & o);
substitution const & s = substitution(), unifier_config const & c = unifier_config());
/**
The unifier divides the constraints in 8 groups: Simple, Basic, FlexRigid, PluginDelayed, DelayedChoice, ClassInstance, FlexFlex, MaxDelayed

2
tests/lean/run/list_elab1.lean
View file

@ -11,7 +11,7 @@
import data.nat
using nat eq_proofs
set_option unifier.expensive true
inductive list (T : Type) : Type :=
| nil {} : list T
| cons : T → list T → list T

2
tests/lean/run/over_subst.lean
View file

@ -27,7 +27,5 @@ end int
using int
using nat
set_option unifier.expensive true
theorem add_lt_left {a b : int} (H : a < b) (c : int) : c + a < c + b :=
subst (symm (add_assoc c a one)) (add_le_left H c)

4
tests/lean/slow/list_elab2.lean
View file

@ -12,14 +12,12 @@
import logic data.nat
-- import congr
set_option unifier.expensive true
using nat
-- using congr
using eq_proofs
namespace list
-- Type
-- ----
@ -173,7 +171,6 @@ list_induction_on l (refl _)
assume P : append x l = concat l [x],
P ▸ refl _)
set_option unifier.expensive false
theorem append_eq_reverse_cons (x : T) (l : list T) : append x l = reverse (x :: reverse l) :=
list_induction_on l
(calc
@ -190,4 +187,3 @@ list_induction_on l
... = reverse (x :: (reverse (y :: l'))) : refl _)
end
end list