111 lines
3.8 KiB
C++
111 lines
3.8 KiB
C++
/*
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Copyright (c) 2014 Microsoft Corporation. All rights reserved.
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Released under Apache 2.0 license as described in the file LICENSE.
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Author: Leonardo de Moura
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*/
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#include "kernel/find_fn.h"
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#include "kernel/instantiate.h"
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#include "kernel/type_checker.h"
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#include "kernel/inductive/inductive.h"
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namespace lean {
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/** \brief Return true if environment has a constructor named \c c that returns
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an element of the inductive datatype named \c I, and \c c must have \c nparams parameters.
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*/
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bool has_constructor(environment const & env, name const & c, name const & I, unsigned nparams) {
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auto d = env.find(c);
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if (!d || d->is_definition())
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return false;
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expr type = d->get_type();
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unsigned i = 0;
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while (is_pi(type)) {
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i++;
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type = binding_body(type);
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}
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if (i != nparams)
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return false;
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type = get_app_fn(type);
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return is_constant(type) && const_name(type) == I;
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}
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bool has_unit_decls(environment const & env) {
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return has_constructor(env, name{"unit", "star"}, "unit", 0);
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}
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bool has_eq_decls(environment const & env) {
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return has_constructor(env, name{"eq", "refl"}, "eq", 2);
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}
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bool has_heq_decls(environment const & env) {
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return has_constructor(env, name{"heq", "refl"}, "heq", 2);
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}
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bool has_prod_decls(environment const & env) {
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return has_constructor(env, name{"prod", "mk"}, "prod", 4);
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}
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bool is_recursive_datatype(environment const & env, name const & n) {
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optional<inductive::inductive_decls> decls = inductive::is_inductive_decl(env, n);
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if (!decls)
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return false;
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for (inductive::inductive_decl const & decl : std::get<2>(*decls)) {
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for (inductive::intro_rule const & intro : inductive::inductive_decl_intros(decl)) {
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expr type = inductive::intro_rule_type(intro);
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while (is_pi(type)) {
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if (find(binding_domain(type), [&](expr const & e, unsigned) {
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return is_constant(e) && const_name(e) == n; })) {
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return true;
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}
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type = binding_body(type);
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}
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}
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}
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return false;
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}
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level get_datatype_level(expr ind_type) {
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while (is_pi(ind_type))
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ind_type = binding_body(ind_type);
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return sort_level(ind_type);
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}
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bool is_inductive_predicate(environment const & env, name const & n) {
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if (!env.impredicative())
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return false; // environment does not have Prop
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if (!inductive::is_inductive_decl(env, n))
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return false; // n is not inductive datatype
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return is_zero(get_datatype_level(env.get(n).get_type()));
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}
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expr instantiate_univ_param (expr const & e, name const & p, level const & l) {
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return instantiate_univ_params(e, to_list(p), to_list(l));
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}
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expr to_telescope(name_generator & ngen, expr type, buffer<expr> & telescope, optional<binder_info> const & binfo) {
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while (is_pi(type)) {
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expr local;
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if (binfo)
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local = mk_local(ngen.next(), binding_name(type), binding_domain(type), *binfo);
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else
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local = mk_local(ngen.next(), binding_name(type), binding_domain(type), binding_info(type));
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telescope.push_back(local);
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type = instantiate(binding_body(type), local);
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}
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return type;
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}
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expr to_telescope(type_checker & tc, expr type, buffer<expr> & telescope, optional<binder_info> const & binfo) {
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type = tc.whnf(type).first;
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while (is_pi(type)) {
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expr local;
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if (binfo)
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local = mk_local(tc.mk_fresh_name(), binding_name(type), binding_domain(type), *binfo);
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else
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local = mk_local(tc.mk_fresh_name(), binding_name(type), binding_domain(type), binding_info(type));
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telescope.push_back(local);
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type = tc.whnf(instantiate(binding_body(type), local)).first;
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}
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return type;
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}
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}
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