lean2/src/frontends/lean/decl_cmds.cpp

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/*
Copyright (c) 2014 Microsoft Corporation. All rights reserved.
Released under Apache 2.0 license as described in the file LICENSE.
Author: Leonardo de Moura
*/
#include <algorithm>
#include "util/sstream.h"
#include "kernel/type_checker.h"
#include "library/scoped_ext.h"
#include "library/aliases.h"
#include "library/private.h"
#include "library/placeholder.h"
#include "library/locals.h"
#include "library/explicit.h"
#include "frontends/lean/parser.h"
#include "frontends/lean/util.h"
namespace lean {
static name g_llevel_curly(".{");
static name g_lcurly("{");
static name g_rcurly("}");
static name g_lbracket("[");
static name g_rbracket("]");
static name g_colon(":");
static name g_assign(":=");
static name g_private("[private]");
static name g_inline("[inline]");
environment universe_cmd(parser & p) {
name n = p.check_id_next("invalid universe declaration, identifier expected");
check_atomic(n);
environment env = p.env();
if (in_section(env)) {
p.add_local_level(n, mk_param_univ(n));
} else {
name const & ns = get_namespace(env);
name full_n = ns + n;
env = module::add_universe(env, full_n);
if (!ns.is_anonymous())
env = add_alias(env, n, mk_global_univ(full_n));
}
return env;
}
binder_info parse_open_binder_info(parser & p) {
if (p.curr_is_token(g_lcurly)) {
check_in_section(p);
p.next();
return mk_implicit_binder_info();
} else if (p.curr_is_token(g_lbracket)) {
check_in_section(p);
p.next();
return mk_cast_binder_info();
} else {
return binder_info();
}
}
void parse_close_binder_info(parser & p, binder_info const & bi) {
if (bi.is_implicit()) {
p.check_token_next(g_rcurly, "invalid declaration, '}' expected");
} else if (bi.is_cast()) {
p.check_token_next(g_rbracket, "invalid declaration, ']' expected");
}
}
bool parse_univ_params(parser & p, buffer<name> & ps) {
if (p.curr_is_token(g_llevel_curly)) {
p.next();
while (!p.curr_is_token(g_rcurly)) {
name l = p.check_id_next("invalid universe parameter, identifier expected");
p.add_local_level(l, mk_param_univ(l));
ps.push_back(l);
}
p.next();
return true;
} else{
return false;
}
}
void update_univ_parameters(buffer<name> & ls_buffer, name_set const & found, parser const & p) {
unsigned old_sz = ls_buffer.size();
found.for_each([&](name const & n) {
if (std::find(ls_buffer.begin(), ls_buffer.begin() + old_sz, n) == ls_buffer.begin() + old_sz)
ls_buffer.push_back(n);
});
std::sort(ls_buffer.begin(), ls_buffer.end(), [&](name const & n1, name const & n2) {
return p.get_local_level_index(n1) < p.get_local_level_index(n2);
});
}
static environment declare_var(parser & p, environment env,
name const & n, level_param_names const & ls, expr const & type,
bool is_axiom, binder_info const & bi, pos_info const & pos) {
if (in_section(p.env())) {
p.add_local_expr(n, p.save_pos(mk_local(n, type), pos), bi);
return env;
} else {
name const & ns = get_namespace(env);
name full_n = ns + n;
if (is_axiom)
env = module::add(env, check(env, mk_axiom(full_n, ls, type)));
else
env = module::add(env, check(env, mk_var_decl(full_n, ls, type)));
if (!ns.is_anonymous())
env = add_alias(env, n, mk_constant(full_n));
return env;
}
}
environment variable_cmd_core(parser & p, bool is_axiom) {
auto pos = p.pos();
binder_info bi = parse_open_binder_info(p);
name n = p.check_id_next("invalid declaration, identifier expected");
check_atomic(n);
buffer<name> ls_buffer;
if (p.curr_is_token(g_llevel_curly) && in_section(p.env()))
throw parser_error("invalid declaration, axioms/parameters occurring in sections cannot be universe polymorphic", p.pos());
optional<parser::local_scope> scope1;
if (!in_section(p.env()))
scope1.emplace(p);
parse_univ_params(p, ls_buffer);
parser::param_universe_scope scope2(p);
expr type;
if (!p.curr_is_token(g_colon)) {
buffer<parameter> ps;
auto lenv = p.parse_binders(ps);
p.check_token_next(g_colon, "invalid declaration, ':' expected");
type = p.parse_scoped_expr(ps, lenv);
type = p.pi_abstract(ps, type);
} else {
p.next();
type = p.parse_expr();
}
parse_close_binder_info(p, bi);
level_param_names ls;
if (in_section(p.env())) {
ls = to_level_param_names(collect_univ_params(type));
} else {
update_univ_parameters(ls_buffer, collect_univ_params(type), p);
ls = to_list(ls_buffer.begin(), ls_buffer.end());
}
type = p.elaborate(type);
return declare_var(p, p.env(), n, ls, type, is_axiom, bi, pos);
}
environment variable_cmd(parser & p) {
return variable_cmd_core(p, false);
}
environment axiom_cmd(parser & p) {
return variable_cmd_core(p, true);
}
// Sort local_names by order of occurrence in the section, and copy the associated parameters to section_ps
void mk_section_params(name_set const & local_names, parser const & p, buffer<parameter> & section_ps) {
local_names.for_each([&](name const & n) {
section_ps.push_back(*p.get_local(n));
});
std::sort(section_ps.begin(), section_ps.end(), [&](parameter const & p1, parameter const & p2) {
return p.get_local_index(mlocal_name(p1.m_local)) < p.get_local_index(mlocal_name(p2.m_local));
});
}
// Collect local (section) constants occurring in type and value, sort them, and store in section_ps
void collect_section_locals(expr const & type, expr const & value, parser const & p, buffer<parameter> & section_ps) {
name_set ls = collect_locals(type, collect_locals(value));
return mk_section_params(ls, p, section_ps);
}
static void parse_modifiers(parser & p, bool & is_private, bool & is_opaque) {
while (true) {
if (p.curr_is_token(g_private)) {
is_private = true;
p.next();
} else if (p.curr_is_token(g_inline)) {
is_opaque = false;
p.next();
} else {
break;
}
}
}
// Return the levels in \c ls that are defined in the section
levels collect_section_levels(level_param_names const & ls, parser & p) {
buffer<level> section_ls_buffer;
for (name const & l : ls) {
if (p.get_local_level_index(l))
section_ls_buffer.push_back(mk_param_univ(l));
else
break;
}
return to_list(section_ls_buffer.begin(), section_ls_buffer.end());
}
environment definition_cmd_core(parser & p, bool is_theorem, bool is_opaque) {
name n = p.check_id_next("invalid declaration, identifier expected");
check_atomic(n);
bool is_private = false;
parse_modifiers(p, is_private, is_opaque);
if (is_theorem && !is_opaque)
throw exception("invalid theorem declaration, theorems cannot be transparent");
environment env = p.env();
name real_n; // real name for this declaration
if (is_private) {
auto env_n = add_private_name(env, n, optional<unsigned>(hash(p.pos().first, p.pos().second)));
env = env_n.first;
real_n = env_n.second;
} else {
name const & ns = get_namespace(env);
real_n = ns + n;
}
buffer<name> ls_buffer;
expr type, value;
level_param_names ls;
{
parser::local_scope scope1(p);
parse_univ_params(p, ls_buffer);
if (p.curr_is_token(g_assign)) {
auto pos = p.pos();
p.next();
type = p.save_pos(mk_expr_placeholder(), pos);
value = p.parse_expr();
} else if (p.curr_is_token(g_colon)) {
p.next();
{
parser::param_universe_scope scope2(p);
type = p.parse_expr();
}
p.check_token_next(g_assign, "invalid declaration, ':=' expected");
value = p.parse_expr();
} else {
buffer<parameter> ps;
optional<local_environment> lenv;
{
parser::param_universe_scope scope2(p);
lenv = p.parse_binders(ps);
p.check_token_next(g_colon, "invalid declaration, ':' expected");
type = p.parse_scoped_expr(ps, *lenv);
}
p.check_token_next(g_assign, "invalid declaration, ':=' expected");
value = p.parse_scoped_expr(ps, *lenv);
type = p.pi_abstract(ps, type);
value = p.lambda_abstract(ps, value);
}
update_univ_parameters(ls_buffer, collect_univ_params(value, collect_univ_params(type)), p);
ls = to_list(ls_buffer.begin(), ls_buffer.end());
}
if (in_section(env)) {
buffer<parameter> section_ps;
collect_section_locals(type, value, p, section_ps);
type = p.pi_abstract(section_ps, type);
value = p.lambda_abstract(section_ps, value);
levels section_ls = collect_section_levels(ls, p);
buffer<expr> section_args;
for (auto const & p : section_ps)
section_args.push_back(p.m_local);
expr ref = mk_app(mk_explicit(mk_constant(real_n, section_ls)), section_args);
p.add_local_expr(n, ref);
} else {
if (real_n != n)
env = add_alias(env, n, mk_constant(real_n));
}
if (is_theorem) {
// TODO(Leo): delay theorems
auto type_value = p.elaborate(n, type, value);
type = type_value.first;
value = type_value.second;
env = module::add(env, check(env, mk_theorem(real_n, ls, type, value)));
} else {
auto type_value = p.elaborate(n, type, value);
type = type_value.first;
value = type_value.second;
env = module::add(env, check(env, mk_definition(env, real_n, ls, type, value, is_opaque)));
}
return env;
}
environment definition_cmd(parser & p) {
return definition_cmd_core(p, false, true);
}
environment abbreviation_cmd(parser & p) {
return definition_cmd_core(p, false, false);
}
environment theorem_cmd(parser & p) {
return definition_cmd_core(p, true, true);
}
static environment variables_cmd(parser & p) {
auto pos = p.pos();
buffer<name> ids;
binder_info bi = parse_open_binder_info(p);
while (!p.curr_is_token(g_colon)) {
name id = p.check_id_next("invalid parameters declaration, identifier expected");
check_atomic(id);
ids.push_back(id);
}
p.next();
optional<parser::local_scope> scope1;
if (!in_section(p.env()))
scope1.emplace(p);
parser::param_universe_scope scope2(p);
expr type = p.parse_expr();
parse_close_binder_info(p, bi);
level_param_names ls = to_level_param_names(collect_univ_params(type));
type = p.elaborate(type);
environment env = p.env();
for (auto id : ids)
env = declare_var(p, env, id, ls, type, true, bi, pos);
return env;
}
void register_decl_cmds(cmd_table & r) {
add_cmd(r, cmd_info("universe", "declare a global universe level", universe_cmd));
add_cmd(r, cmd_info("variable", "declare a new parameter", variable_cmd));
add_cmd(r, cmd_info("axiom", "declare a new axiom", axiom_cmd));
add_cmd(r, cmd_info("definition", "add new definition", definition_cmd));
add_cmd(r, cmd_info("abbreviation", "add new abbreviation (aka transparent definition)", abbreviation_cmd));
add_cmd(r, cmd_info("theorem", "add new theorem", theorem_cmd));
add_cmd(r, cmd_info("variables", "declare new parameters", variables_cmd));
}
}