lean2/src/frontends/lean/builtin_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/io_state_stream.h"
#include "library/scoped_ext.h"
#include "library/aliases.h"
#include "library/private.h"
#include "library/locals.h"
#include "frontends/lean/parser.h"
namespace lean {
static name g_raw("raw");
static name g_llevel_curly(".{");
static name g_rcurly("}");
static name g_colon(":");
static name g_assign(":=");
static name g_private("[private]");
static name g_inline("[inline]");
static void check_atomic(name const & n) {
if (!n.is_atomic())
throw exception(sstream() << "invalid declaration name '" << n << "', identifier must be atomic");
}
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 = env.add_universe(full_n);
if (!ns.is_anonymous())
env = add_alias(env, n, mk_global_univ(full_n));
}
return env;
}
static void check_in_section(parser const & p) {
if (!in_section(p.env()))
throw exception(sstream() << "invalid command, it must be used in a section");
}
static void 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();
}
}
struct local_scope_if_not_section {
parser & m_p;
local_scope_if_not_section(parser & p):m_p(p) {
if (!in_section(p.env()))
p.push_local_scope();
}
~local_scope_if_not_section() {
if (!in_section(m_p.env()))
m_p.pop_local_scope();
}
};
static void update_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);
});
}
environment variable_cmd_core(parser & p, bool is_axiom, binder_info const & bi) {
name n = p.check_id_next("invalid declaration, identifier expected");
check_atomic(n);
buffer<name> ls_buffer;
buffer<parameter> ps;
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());
local_scope_if_not_section scope(p);
parse_univ_params(p, ls_buffer);
p.set_type_use_placeholder(false);
if (!p.curr_is_token(g_colon))
p.parse_binders(ps);
p.check_token_next(g_colon, "invalid declaration, ':' expected");
expr type = p.parse_scoped_expr(ps);
level_param_names ls;
if (in_section(p.env())) {
ls = to_level_param_names(collect_univ_params(type));
} else {
update_parameters(ls_buffer, collect_univ_params(type), p);
ls = to_list(ls_buffer.begin(), ls_buffer.end());
}
type = p.pi_abstract(ps, type);
type = p.elaborate(type, ls);
if (in_section(p.env())) {
p.add_local_expr(n, mk_local(n, n, type), bi);
return p.env();
} else {
environment env = p.env();
name const & ns = get_namespace(env);
name full_n = ns + n;
if (is_axiom)
env = env.add(check(env, mk_axiom(full_n, ls, type)));
else
env = env.add(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(parser & p) {
return variable_cmd_core(p, false, binder_info());
}
environment axiom_cmd(parser & p) {
return variable_cmd_core(p, true, binder_info());
}
environment implicit_variable_cmd(parser & p) {
check_in_section(p);
return variable_cmd_core(p, false, mk_implicit_binder_info());
}
environment implicit_axiom_cmd(parser & p) {
check_in_section(p);
return variable_cmd_core(p, true, mk_implicit_binder_info());
}
environment cast_variable_cmd(parser & p) {
check_in_section(p);
return variable_cmd_core(p, false, mk_cast_binder_info());
}
// Collect local (section) constants occurring in type and value, sort them, and store in section_ps
static 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));
ls.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));
});
}
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;
}
}
}
// Wrap \c e with the "explicit macro", the idea is to inform the elaborator
// preprocessor, that we do not need create metavariables for implicit arguments
static expr mark_explicit(expr const & e) {
// TODO(Leo)
return e;
}
environment definition_cmd_core(parser & p, bool is_theorem, bool is_opaque) {
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");
name n = p.check_id_next("invalid declaration, identifier expected");
check_atomic(n);
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 scope(p);
parse_univ_params(p, ls_buffer);
p.set_type_use_placeholder(false);
buffer<parameter> ps;
if (!p.curr_is_token(g_colon))
p.parse_binders(ps);
p.check_token_next(g_colon, "invalid declaration, ':' expected");
type = p.parse_scoped_expr(ps);
p.check_token_next(g_assign, "invalid declaration, ':=' expected");
p.set_type_use_placeholder(true);
value = p.parse_scoped_expr(ps);
type = p.pi_abstract(ps, type);
value = p.lambda_abstract(ps, value);
update_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);
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;
}
levels section_ls = to_list(section_ls_buffer.begin(), section_ls_buffer.end());
buffer<expr> section_args;
for (auto const & p : section_ps)
section_args.push_back(p.m_local);
expr ref = mk_app(mark_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(type, value, ls);
type = type_value.first;
value = type_value.second;
env = env.add(check(env, mk_theorem(real_n, ls, type, value)));
} else {
auto type_value = p.elaborate(type, value, ls);
type = type_value.first;
value = type_value.second;
env = env.add(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);
}
environment print_cmd(parser & p) {
if (p.curr() == scanner::token_kind::String) {
p.regular_stream() << p.get_str_val() << "\n";
p.next();
} else if (p.curr_is_token(g_raw)) {
p.next();
expr e = p.parse_expr();
p.regular_stream() << e << "\n";
} else {
throw parser_error("invalid print command", p.pos());
}
return p.env();
}
environment section_cmd(parser & p) {
p.push_local_scope();
return push_scope(p.env(), p.ios());
}
environment namespace_cmd(parser & p) {
name n = p.check_id_next("invalid namespace declaration, identifier expected");
check_atomic(n);
return push_scope(p.env(), p.ios(), n);
}
environment end_scoped_cmd(parser & p) {
if (in_section(p.env()))
p.pop_local_scope();
return pop_scope(p.env());
}
environment check_cmd(parser & p) {
expr e = p.parse_expr();
level_param_names ls = to_level_param_names(collect_univ_params(e));
e = p.elaborate(e, ls);
expr type = type_checker(p.env()).check(e, ls);
p.regular_stream() << e << " : " << type << endl;
return p.env();
}
environment set_line_cmd(parser & p) {
if (!p.curr_is_numeral())
throw parser_error("invalid #setline command, numeral expected", p.pos());
unsigned r = p.get_small_nat();
p.set_line(r);
p.next();
return p.env();
}
cmd_table init_cmd_table() {
cmd_table r;
add_cmd(r, cmd_info("print", "print a string", print_cmd));
add_cmd(r, cmd_info("universe", "declare a global universe level", universe_cmd));
add_cmd(r, cmd_info("section", "open a new section", section_cmd));
add_cmd(r, cmd_info("namespace", "open a new namespace", namespace_cmd));
add_cmd(r, cmd_info("end", "close the current namespace/section", end_scoped_cmd));
add_cmd(r, cmd_info("variable", "declare a new parameter", variable_cmd));
add_cmd(r, cmd_info("{variable}", "declare a new implict parameter", implicit_variable_cmd));
add_cmd(r, cmd_info("[variable]", "declare a new cast parameter", cast_variable_cmd));
add_cmd(r, cmd_info("axiom", "declare a new axiom", axiom_cmd));
add_cmd(r, cmd_info("{axiom}", "declare a new implicit axiom", implicit_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("check", "type check given expression, and display its type", check_cmd));
add_cmd(r, cmd_info("#setline", "modify the current line number, it only affects error/report messages", set_line_cmd));
return r;
}
cmd_table get_builtin_cmds() {
static optional<cmd_table> r;
if (!r)
r = init_cmd_table();
return *r;
}
}