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fix(library/tactic/constructor_tactic): bug in constructor tactic

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see example (constr_tac2.lean) in comment at issue #500
This commit is contained in:
Leonardo de Moura 2015-04-30 20:18:24 -07:00
parent d18f9c7607
commit 15e52b06df
4 changed files with 31 additions and 27 deletions
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8
src/library/tactic/apply_tactic.cpp
View file

@ -67,8 +67,6 @@ static void remove_redundant_metas(buffer<expr> & metas) {
enum subgoals_action_kind { IgnoreSubgoals, AddRevSubgoals, AddSubgoals, AddAllSubgoals };
static proof_state_seq apply_tactic_core(environment const & env, io_state const & ios, proof_state const & s,
expr const & _e, buffer<constraint> & cs,
bool add_meta, subgoals_action_kind subgoals_action) {
@ -178,6 +176,12 @@ static proof_state_seq apply_tactic_core(environment const & env, io_state const
return apply_tactic_core(env, ios, s, e, cs, add_meta, subgoals_action);
}
proof_state_seq apply_tactic_core(environment const & env, io_state const & ios, proof_state const & s, expr const & e, constraint_seq const & cs) {
buffer<constraint> tmp_cs;
cs.linearize(tmp_cs);
return apply_tactic_core(env, ios, s, e, tmp_cs, true, AddAllSubgoals);
}
tactic eassumption_tactic() {
return tactic([=](environment const & env, io_state const & ios, proof_state const & s) {
goals const & gs = s.get_goals();

1
src/library/tactic/apply_tactic.h
View file

@ -8,6 +8,7 @@ Author: Leonardo de Moura
#include "util/lua.h"
#include "library/tactic/elaborate.h"
namespace lean {
proof_state_seq apply_tactic_core(environment const & env, io_state const & ios, proof_state const & s, expr const & e, constraint_seq const & cs);
tactic apply_tactic(elaborate_fn const & fn, expr const & e);
tactic fapply_tactic(elaborate_fn const & fn, expr const & e);
tactic eassumption_tactic();

42
src/library/tactic/constructor_tactic.cpp
View file

@ -10,6 +10,7 @@ Author: Leonardo de Moura
#include "library/util.h"
#include "library/reducible.h"
#include "library/tactic/expr_to_tactic.h"
#include "library/tactic/apply_tactic.h"
namespace lean {
/**
@ -25,78 +26,69 @@ tactic constructor_tactic(elaborate_fn const & elab, unsigned _i, optional<unsig
goals const & gs = s.get_goals();
if (empty(gs)) {
throw_no_goal_if_enabled(s);
return optional<proof_state>();
return proof_state_seq();
}
if (_i == 0) {
throw_tactic_exception_if_enabled(s, "invalid 'constructor' tactic, index must be greater than zero");
return optional<proof_state>();
return proof_state_seq();
}
constraint_seq cs;
unsigned i = _i - 1;
name_generator ngen = s.get_ngen();
auto tc = mk_type_checker(env, ngen.mk_child(), s.relax_main_opaque());
goal const & g = head(gs);
expr t = tc->whnf(g.get_type()).first;
expr t = tc->whnf(g.get_type(), cs);
buffer<expr> I_args;
expr I = get_app_args(t, I_args);
if (!is_constant(I) || !inductive::is_inductive_decl(env, const_name(I))) {
throw_tactic_exception_if_enabled(s, "invalid 'constructor' tactic, goal is not an inductive datatype");
return none_proof_state();
return proof_state_seq();
}
buffer<name> c_names;
get_intro_rule_names(env, const_name(I), c_names);
if (num_constructors && c_names.size() != *num_constructors) {
throw_tactic_exception_if_enabled(s, sstream() << "invalid 'constructor' tactic, goal is an inductive datatype, "
<< "but it does not have " << *num_constructors << " constructor(s)");
return none_proof_state();
return proof_state_seq();
}
if (i >= c_names.size()) {
throw_tactic_exception_if_enabled(s, sstream() << "invalid 'constructor' tactic, goal is an inductive datatype, "
<< "but it has only " << c_names.size() << " constructor(s)");
return none_proof_state();
return proof_state_seq();
}
expr C = mk_constant(c_names[i], const_levels(I));
unsigned num_params = *inductive::get_num_params(env, const_name(I));
if (I_args.size() < num_params)
return none_proof_state();
return proof_state_seq();
proof_state new_s(s, ngen);
C = mk_app(C, num_params, I_args.data());
expr C_type = tc->whnf(tc->infer(C).first).first;
expr C_type = tc->whnf(tc->infer(C, cs), cs);
bool report_unassigned = true;
bool enforce_type = true;
for (expr const & arg : given_args) {
if (!is_pi(C_type)) {
throw_tactic_exception_if_enabled(s, sstream() << "invalid 'constructor' tactic, "
<< "too many arguments have been provided");
return none_proof_state();
return proof_state_seq();
}
try {
if (auto new_arg = elaborate_with_respect_to(env, ios, elab, new_s, arg, some_expr(binding_domain(C_type)),
report_unassigned, enforce_type)) {
C = mk_app(C, *new_arg);
C_type = tc->whnf(instantiate(binding_body(C_type), *new_arg)).first;
C_type = tc->whnf(instantiate(binding_body(C_type), *new_arg), cs);
} else {
return none_proof_state();
return proof_state_seq();
}
} catch (exception &) {
if (new_s.report_failure())
throw;
return none_proof_state();
return proof_state_seq();
}
}
buffer<goal> new_goals;
while (is_pi(C_type)) {
expr new_type = binding_domain(C_type);
expr new_meta = g.mk_meta(tc->mk_fresh_name(), new_type);
goal new_goal(new_meta, new_type);
new_goals.push_back(new_goal);
C = mk_app(C, new_meta);
C_type = tc->whnf(instantiate(binding_body(C_type), new_meta)).first;
}
substitution new_subst = new_s.get_subst();
assign(new_subst, g, C);
return some_proof_state(proof_state(new_s, to_list(new_goals.begin(), new_goals.end(), tail(gs)), new_subst));
return apply_tactic_core(env, ios, new_s, C, cs);
};
return tactic01(fn);
return tactic(fn);
}
void initialize_constructor_tactic() {

7
tests/lean/run/constr_tac2.lean Normal file
View file

@ -0,0 +1,7 @@
open nat
example (n m : ℕ) (H : n < m) : n < succ m :=
begin
constructor 2,
exact H
end