lean4-htt/src/frontends/lean/decl_util.cpp
2019-03-15 15:04:40 -07:00

581 lines
23 KiB
C++

/*
Copyright (c) 2016 Microsoft Corporation. All rights reserved.
Released under Apache 2.0 license as described in the file LICENSE.
Author: Leonardo de Moura
*/
#include <algorithm>
#include "kernel/instantiate.h"
#include "kernel/abstract.h"
#include "kernel/for_each_fn.h"
#include "kernel/replace_fn.h"
#include "library/locals.h"
#include "library/class.h"
#include "library/trace.h"
#include "library/placeholder.h"
#include "library/protected.h"
#include "library/private.h"
#include "library/aliases.h"
#include "library/explicit.h"
#include "library/reducible.h"
#include "library/aux_match.h"
#include "frontends/lean/util.h"
#include "frontends/lean/decl_util.h"
#include "frontends/lean/tokens.h"
#include "frontends/lean/decl_attributes.h"
#include "frontends/lean/parser.h"
#include "frontends/lean/elaborator.h"
namespace lean {
bool parse_univ_params(parser & p, buffer<name> & lp_names) {
if (p.curr_is_token(get_lcurly_tk())) {
p.next();
while (!p.curr_is_token(get_rcurly_tk())) {
auto pos0 = p.pos();
name l = p.check_atomic_id_next("invalid declaration, identifier expected");
lp_names.push_back(l);
p.add_local_level(l, mk_univ_param(l));
if (p.pos() == pos0) break;
}
p.next();
return true;
} else {
return false;
}
}
name synthesize_instance_name(parser & p, expr const & type, declaration_name_scope & scope, pos_info const & c_pos) {
name c_name;
expr it = type;
while (is_pi(it)) it = binding_body(it);
expr const & C = unwrap_pos(get_app_fn(it));
name ns = get_namespace(p.env());
if (is_constant(C) && !ns.is_anonymous()) {
c_name = const_name(C);
scope.set_name(c_name);
} else if (is_constant(C) && is_app(it) && is_constant(unwrap_pos(get_app_fn(app_arg(it))))) {
c_name = const_name(unwrap_pos(get_app_fn(app_arg(it)))) + const_name(C);
scope.set_name(c_name);
} else {
p.maybe_throw_error({"failed to synthesize instance name, name should be provided explicitly", c_pos});
c_name = mk_unused_name(p.env(), "_inst");
}
return c_name;
}
expr parse_single_header(parser & p, declaration_name_scope & scope, buffer <name> & lp_names, buffer <expr> & params,
bool is_example, bool is_instance) {
auto c_pos = p.pos();
name c_name;
if (is_example) {
c_name = "_example";
scope.set_name(c_name);
} else {
if (!is_instance)
parse_univ_params(p, lp_names);
if (!is_instance || p.curr_is_identifier()) {
c_name = p.check_decl_id_next("invalid declaration, identifier expected");
scope.set_name(c_name);
}
}
p.parse_optional_binders(params, /* allow_default */ true, /* explicit delimiters */ true);
for (expr const & param : params)
p.add_local(param);
expr type;
if (p.curr_is_token(get_colon_tk())) {
p.next();
type = p.parse_expr();
} else {
type = p.save_pos(mk_expr_placeholder(), c_pos);
}
if (is_instance && c_name.is_anonymous()) {
if (used_match_idx())
throw parser_error("invalid instance, pattern matching cannot be used in the type of anonymous instance declarations", c_pos);
c_name = synthesize_instance_name(p, type, scope, c_pos);
}
lean_assert(!c_name.is_anonymous());
return p.save_pos(mk_local(c_name, type), c_pos);
}
void parse_mutual_header(parser & p, buffer <name> & lp_names, buffer <expr> & cs, buffer <expr> & params) {
parse_univ_params(p, lp_names);
while (true) {
auto c_pos = p.pos();
name c_name = p.check_decl_id_next("invalid mutual declaration, identifier expected");
cs.push_back(p.save_pos(mk_local(c_name, mk_expr_placeholder()), c_pos));
if (!p.curr_is_token(get_comma_tk()))
break;
p.next();
}
if (cs.size() < 2) {
throw parser_error("invalid mutual declaration, must provide more than one identifier (separated by commas)", p.pos());
}
p.parse_optional_binders(params, /* allow_default */ true, /* explicit delimiters */ true);
for (expr const & param : params)
p.add_local(param);
for (expr const & c : cs)
p.add_local(c);
}
pair<expr, decl_attributes> parse_inner_header(parser & p, name const & c_expected) {
decl_attributes attrs;
p.check_token_next(get_with_tk(), "invalid mutual declaration, 'with' expected");
attrs.parse(p);
auto id_pos = p.pos();
name n = p.check_decl_id_next("invalid mutual declaration, identifier expected");
if (c_expected != n)
throw parser_error(sstream() << "invalid mutual declaration, '" << c_expected << "' expected",
id_pos);
/* Remark: if this is a private definition, the private prefix must have been set
before invoking this procedure. */
declaration_name_scope scope(n);
p.check_token_next(get_colon_tk(), "invalid mutual declaration, ':' expected");
return mk_pair(p.parse_expr(), attrs);
}
/** \brief Version of collect_locals(expr const & e, collected_locals & ls) that ignores local constants occurring in
tactics. */
void collect_locals_ignoring_tactics(expr const & e, collected_locals & ls) {
if (!has_local(e)) return;
for_each(e, [&](expr const & e, unsigned) {
if (!has_local(e)) return false;
if (is_local(e)) ls.insert(e);
return true;
});
}
name_set collect_univ_params_ignoring_tactics(expr const & e, name_set const & ls) {
if (!has_param_univ(e)) return ls;
name_set r = ls;
for_each(e, [&](expr const & e, unsigned) {
if (!has_param_univ(e)) {
return false;
} else if (is_sort(e)) {
collect_univ_params_core(sort_level(e), r);
} else if (is_constant(e)) {
for (auto const & l : const_levels(e))
collect_univ_params_core(l, r);
}
return true;
});
return r;
}
/** \brief Collect annonymous instances in section/namespace declarations such as:
variable [decidable_eq A]
Instances are included only if all section variables/parameters they reference have already
been included. For variables in out_param position, the logic is inverted: If the instance is
included, we also include those arguments.
*/
void collect_annonymous_inst_implicit(parser const & p, collected_locals & locals) {
buffer<pair<name, expr>> entries;
to_buffer(p.get_local_entries(), entries);
type_context_old ctx(p.env());
unsigned i = entries.size();
while (i > 0) {
--i;
auto const & entry = entries[i];
expr l = unwrap_pos(entry.second);
if (is_local(l) && !locals.contains(l) && is_inst_implicit(local_info_p(l)) &&
// remark: remove the following condition condition, if we want to auto inclusion also for non anonymous ones.
is_anonymous_inst_name(entry.first)) {
expr type = local_type_p(l);
buffer<expr> C_args;
expr C = get_app_args(type, C_args);
if (!is_const(C))
continue;
expr it2 = ctx.infer(C);
collected_locals new_locals;
bool ok = true;
for (expr & C_arg : C_args) {
it2 = ctx.relaxed_whnf(it2);
lean_assert(is_pi(it2));
expr const & d = binding_domain(it2);
if (is_local_p(C_arg) && is_class_out_param(d)) {
new_locals.insert(unwrap_pos(C_arg));
} else {
for_each(C_arg, [&](expr const & e, unsigned) {
if (!ok) return false; // stop
if (is_local(e) && !(locals.contains(e) || new_locals.contains(e)))
ok = false;
return true;
});
}
it2 = instantiate(binding_body(it2), C_arg);
}
if (ok) {
for (auto & l : new_locals.get_collected()) {
locals.insert(l);
}
locals.insert(l);
}
}
}
}
/** \brief Sort local names by order of occurrence, and copy the associated parameters to ps */
void sort_locals(buffer<expr> const & locals, parser const & p, buffer<expr> & ps) {
buffer<expr> extra;
name_set explicit_param_names;
for (expr const & p : ps) {
explicit_param_names.insert(local_name_p(p));
}
for (expr const & l : locals) {
// we only copy the locals that are in p's local context
if (p.is_local_decl_user_name(l) && !explicit_param_names.contains(local_name_p(l)))
extra.push_back(l);
}
std::sort(extra.begin(), extra.end(), [&](expr const & p1, expr const & p2) {
bool is_var1 = p.is_local_variable(p1);
bool is_var2 = p.is_local_variable(p2);
if (!is_var1 && is_var2)
return true;
else if (is_var1 && !is_var2)
return false;
else
return p.get_local_index(p1) < p.get_local_index(p2);
});
buffer<expr> new_ps;
new_ps.append(extra);
new_ps.append(ps);
ps.clear();
ps.append(new_ps);
}
/** TODO(Leo): mark as static */
void update_univ_parameters(parser & p, buffer<name> & lp_names, name_set const & found) {
unsigned old_sz = lp_names.size();
found.for_each([&](name const & n) {
if (std::find(lp_names.begin(), lp_names.begin() + old_sz, n) == lp_names.begin() + old_sz)
lp_names.push_back(n);
});
std::sort(lp_names.begin(), lp_names.end(), [&](name const & n1, name const & n2) {
return p.get_local_level_index(n1) < p.get_local_level_index(n2);
});
}
expr replace_locals_preserving_pos_info(expr const & e, unsigned sz, expr const * from, expr const * to) {
return replace_locals(e, sz, from, to);
}
expr replace_locals_preserving_pos_info(expr const & e, buffer<expr> const & from, buffer<expr> const & to) {
lean_assert(from.size() == to.size());
return replace_locals_preserving_pos_info(e, from.size(), from.data(), to.data());
}
expr replace_local_preserving_pos_info(expr const & e, expr const & from, expr const & to) {
return replace_locals_preserving_pos_info(e, 1, &from, &to);
}
void collect_implicit_locals(parser & p, buffer<name> & lp_names, buffer<expr> & params, buffer<expr> const & all_exprs) {
collected_locals locals;
buffer<expr> include_vars;
name_set lp_found;
name_set given_params;
/* Process variables included using the 'include' command */
p.get_include_variables(include_vars);
for (expr const & param : include_vars) {
expr up = unwrap_pos(param);
if (is_local(up)) {
collect_locals_ignoring_tactics(local_type(up), locals);
lp_found = collect_univ_params_ignoring_tactics(local_type(up), lp_found);
locals.insert(up);
}
}
/* Process explicit parameters */
for (expr const & param : params) {
collect_locals_ignoring_tactics(local_type_p(param), locals);
lp_found = collect_univ_params_ignoring_tactics(local_type_p(param), lp_found);
locals.insert(param);
given_params.insert(local_name_p(param));
}
/* Process expressions used to define declaration. */
for (expr const & e : all_exprs) {
collect_locals_ignoring_tactics(e, locals);
lp_found = collect_univ_params_ignoring_tactics(e, lp_found);
}
collect_annonymous_inst_implicit(p, locals);
sort_locals(locals.get_collected(), p, params);
update_univ_parameters(p, lp_names, lp_found);
/* Add as_is annotation to section variables and parameters */
buffer<expr> old_params;
for (unsigned i = 0; i < params.size(); i++) {
expr & param = params[i];
old_params.push_back(param);
expr type = local_type_p(param);
expr new_type = replace_locals_preserving_pos_info(type, i, old_params.data(), params.data());
if (!given_params.contains(local_name_p(param))) {
new_type = copy_pos(type, mk_as_is(new_type));
}
param = copy_pos(param, update_local_p(param, new_type));
}
}
void collect_implicit_locals(parser & p, buffer<name> & lp_names, buffer<expr> & params, std::initializer_list<expr> const & all_exprs) {
buffer<expr> tmp; tmp.append(all_exprs.size(), all_exprs.begin());
collect_implicit_locals(p, lp_names, params, tmp);
}
void collect_implicit_locals(parser & p, buffer<name> & lp_names, buffer<expr> & params, expr const & e) {
buffer<expr> all_exprs; all_exprs.push_back(e);
collect_implicit_locals(p, lp_names, params, all_exprs);
}
void elaborate_params(elaborator & elab, buffer<expr> const & params, buffer<expr> & new_params) {
for (unsigned i = 0; i < params.size(); i++) {
expr const & param = params[i];
expr type = replace_locals_preserving_pos_info(local_type_p(param), i, params.data(), new_params.data());
expr new_type = elab.elaborate_type(type);
expr new_param = elab.push_local(local_pp_name_p(param), new_type, local_info_p(param));
new_params.push_back(new_param);
}
}
environment add_local_ref(parser & p, environment const & env, name const & c_name, name const & c_real_name, buffer<name> const & lp_names, buffer<expr> const & var_params) {
buffer<expr> params;
buffer<name> lps;
for (name const & u : lp_names) {
if (!p.is_local_level(u)) {
/* Stop, it is a definition parameter */
break;
} else if (p.is_local_level_variable(u)) {
/* Stop, it is a parser universe variable (i.e., it has been declared using the `universe variable` command */
break;
} else {
lps.push_back(u);
}
}
for (expr const & e : var_params) {
if (!p.is_local_decl(e)) {
/* Stop, it is a definition parameter */
break;
} else if (p.is_local_variable(e)) {
/* Stop, it is a parser variable (i.e., it has been declared using the `variable` command */
break;
} else {
/* It is a parser parameter (i.e., it has been declared with the `parameter` command */
params.push_back(e);
}
}
if (lps.empty() && params.empty()) return env;
/*
Procedures such as `collect_implicit_locals` wrap parameter types with the `as_is` annotation.
So, we remove these annotations before creating the local reference using `mk_local_ref`.
Remark: the resulting object is wrapped with the macro `as_atomic`.
Remark: The local constants created here and `collect_implicit_locals` are not structurally
equal. That is, `l : ty` is not structurally equal to `l : as_is ty`, but they are definitionally
equal, and moreover the collection method relies on the fact that they have the same internal
id.
*/
buffer<expr> new_params;
for (unsigned i = 0; i < params.size(); i++) {
expr & param = params[i];
expr type = local_type_p(param);
if (is_as_is(type))
type = get_as_is_arg(type);
expr new_type = replace_locals_preserving_pos_info(type, i, params.data(), new_params.data());
new_params.push_back(copy_pos(param, update_local_p(param, new_type)));
}
expr ref = mk_local_ref(c_real_name, lparams_to_levels(names(lps)), new_params);
return p.add_local_ref(env, c_name, ref);
}
environment add_alias(environment const & env, bool is_protected, name const & c_name, name const & c_real_name) {
if (c_name != c_real_name) {
if (is_protected)
return add_expr_alias_rec(env, get_protected_shortest_name(c_real_name), c_real_name);
else
return add_expr_alias_rec(env, c_name, c_real_name);
} else {
return env;
}
}
struct definition_info {
name m_prefix; // prefix for local names
name m_actual_prefix; // actual prefix used to create kernel declaration names. m_prefix and m_actual_prefix are different for scoped/private declarations.
bool m_is_private{true}; // pattern matching outside of definitions should generate private names
/* m_is_unsafe_decl == true iff declaration uses `unsafe` keyword */
bool m_is_unsafe_decl{false};
/* m_is_unsafe == true iff the current subexpression can use unsafe declarations and code.
Remark: a regular (i.e., safe) declaration provided by the user may contain a unsafe subexpression (e.g., tactic).
*/
bool m_is_unsafe{false}; // true iff current block
bool m_is_noncomputable{false};
bool m_is_lemma{false};
bool m_aux_lemmas{false};
bool m_gen_code{true};
unsigned m_next_match_idx{1};
};
MK_THREAD_LOCAL_GET_DEF(definition_info, get_definition_info);
declaration_info_scope::declaration_info_scope(name const & ns, decl_cmd_kind kind, decl_modifiers const & modifiers, bool is_extern) {
definition_info & info = get_definition_info();
lean_assert(info.m_prefix.is_anonymous());
info.m_prefix = name(); // prefix is used to create local name
/* Remark: if info.m_actual_prefix is not `anonymous`, then it has already been set using private_name_scope */
if (info.m_actual_prefix.is_anonymous()) {
info.m_actual_prefix = ns;
}
info.m_is_private = modifiers.m_is_private;
info.m_is_unsafe_decl = modifiers.m_is_unsafe;
info.m_is_unsafe = modifiers.m_is_unsafe;
info.m_is_noncomputable = modifiers.m_is_noncomputable;
info.m_is_lemma = kind == decl_cmd_kind::Theorem;
info.m_aux_lemmas = kind != decl_cmd_kind::Theorem && !modifiers.m_is_unsafe;
info.m_gen_code = !is_extern;
info.m_next_match_idx = 1;
}
declaration_info_scope::declaration_info_scope(parser const & p, decl_cmd_kind kind, decl_modifiers const & modifiers, bool is_extern):
declaration_info_scope(get_namespace(p.env()), kind, modifiers, is_extern) {}
declaration_info_scope::declaration_info_scope(parser const & p, decl_cmd_kind kind, cmd_meta const & meta):
declaration_info_scope(p, kind, meta.m_modifiers, static_cast<bool>(meta.m_attrs.get_attribute(p.env(), "extern"))) {}
declaration_info_scope::~declaration_info_scope() {
get_definition_info() = definition_info();
}
bool declaration_info_scope::gen_aux_lemmas() const {
return get_definition_info().m_aux_lemmas;
}
equations_header mk_equations_header(names const & ns, names const & actual_ns) {
equations_header h;
h.m_num_fns = length(ns);
h.m_fn_names = ns;
h.m_fn_actual_names = actual_ns;
h.m_is_private = get_definition_info().m_is_private;
h.m_is_unsafe = get_definition_info().m_is_unsafe;
h.m_is_noncomputable = get_definition_info().m_is_noncomputable;
h.m_is_lemma = get_definition_info().m_is_lemma;
h.m_aux_lemmas = get_definition_info().m_aux_lemmas;
h.m_gen_code = get_definition_info().m_gen_code;
return h;
}
equations_header mk_equations_header(name const & n, name const & actual_n) {
return mk_equations_header(names(n), names(actual_n));
}
equations_header mk_match_header(name const & n, name const & actual_n) {
equations_header h = mk_equations_header(names(n), names(actual_n));
h.m_gen_code = false;
return h;
}
/* Auxiliary function for creating names for auxiliary declarations.
We avoid propagating the suffix `_main` used by the top-level equations
to the nested declarations. */
static name mk_decl_name(name const & prefix, name const & n) {
if (!prefix.is_atomic() && prefix.is_string() && prefix.get_string() == "_main") {
return prefix.get_prefix() + n;
} else {
return prefix + n;
}
}
bool used_match_idx() {
return get_definition_info().m_next_match_idx > 1;
}
declaration_name_scope::declaration_name_scope() {
definition_info & info = get_definition_info();
m_old_prefix = info.m_prefix;
m_old_actual_prefix = info.m_actual_prefix;
m_old_next_match_idx = info.m_next_match_idx;
info.m_next_match_idx = 1;
}
void declaration_name_scope::set_name(name const & n) {
lean_assert(m_name.is_anonymous());
definition_info & info = get_definition_info();
info.m_prefix = mk_decl_name(info.m_prefix, n);
info.m_actual_prefix = mk_decl_name(info.m_actual_prefix, n);
m_name = info.m_prefix;
m_actual_name = info.m_actual_prefix;
}
declaration_name_scope::declaration_name_scope(name const & n) {
definition_info & info = get_definition_info();
m_old_prefix = info.m_prefix;
m_old_actual_prefix = info.m_actual_prefix;
m_old_next_match_idx = info.m_next_match_idx;
info.m_prefix = mk_decl_name(info.m_prefix, n);
info.m_actual_prefix = mk_decl_name(info.m_actual_prefix, n);
info.m_next_match_idx = 1;
m_name = info.m_prefix;
m_actual_name = info.m_actual_prefix;
}
declaration_name_scope::~declaration_name_scope() {
definition_info & info = get_definition_info();
info.m_prefix = m_old_prefix;
info.m_actual_prefix = m_old_actual_prefix;
info.m_next_match_idx = m_old_next_match_idx;
}
private_name_scope::private_name_scope(bool is_private, environment & env) {
definition_info & info = get_definition_info();
m_old_actual_prefix = info.m_prefix;
m_old_is_private = info.m_is_private;
if (is_private) {
name prv_prefix;
std::tie(env, prv_prefix) = mk_private_prefix(env);
info.m_is_private = true;
info.m_actual_prefix = prv_prefix;
}
}
private_name_scope::~private_name_scope() {
definition_info & info = get_definition_info();
info.m_actual_prefix = m_old_actual_prefix;
info.m_is_private = m_old_is_private;
}
match_definition_scope::match_definition_scope(environment const & env) {
definition_info & info = get_definition_info();
while (true) {
m_name = mk_decl_name(info.m_prefix, mk_aux_match_suffix(info.m_next_match_idx));
m_actual_name = mk_decl_name(info.m_actual_prefix, mk_aux_match_suffix(info.m_next_match_idx));
info.m_next_match_idx++;
if (empty(get_expr_aliases(env, m_name))) {
/* Make sure we don't introduce aliases.
This is important when match-expressions are used in several parameters in a section.
Example:
parameter P : match ... end
parameter Q : match ... end
*/
break;
}
}
}
unsafe_definition_scope::unsafe_definition_scope() {
definition_info & info = get_definition_info();
m_old_is_unsafe = info.m_is_unsafe;
info.m_is_unsafe = true;
}
unsafe_definition_scope::~unsafe_definition_scope() {
definition_info & info = get_definition_info();
info.m_is_unsafe = m_old_is_unsafe;
}
restore_decl_unsafe_scope::restore_decl_unsafe_scope() {
definition_info & info = get_definition_info();
m_old_is_unsafe = info.m_is_unsafe;
info.m_is_unsafe = info.m_is_unsafe_decl;
}
restore_decl_unsafe_scope::~restore_decl_unsafe_scope() {
definition_info & info = get_definition_info();
info.m_is_unsafe = m_old_is_unsafe;
}
}