feat(library/coercion): add coercion management implementation
Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>
This commit is contained in:
Leonardo de Moura
parent
1cff37a084
commit
2be9bcef78
5 changed files with 455 additions and 10 deletions
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@ -349,6 +349,16 @@ expr const & get_app_fn(expr const & e) {
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return *it;
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}
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unsigned get_app_num_args(expr const & e) {
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expr const * it = &e;
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unsigned n = 0;
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while (is_app(*it)) {
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it = &(app_fn(*it));
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n++;
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}
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return n;
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}
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static name g_default_var_name("a");
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bool is_default_var_name(name const & n) { return n == g_default_var_name; }
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expr mk_arrow(expr const & t, expr const & e) { return mk_pi(g_default_var_name, t, e); }
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@ -604,11 +604,10 @@ expr const & get_app_args(expr const & e, buffer<expr> & args);
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If e is of the form <tt>(...(f a1) ... an)</tt>, then the procedure stores [an, ..., a1] in \c args.
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*/
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expr const & get_app_rev_args(expr const & e, buffer<expr> & args);
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/**
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\brief Given of the form <tt>(...(f a1) ... an)</tt>, return \c f. If \c e is not an application,
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then return \c e.
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*/
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/** \brief Given \c e of the form <tt>(...(f a_1) ... a_n)</tt>, return \c f. If \c e is not an application, then return \c e. */
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expr const & get_app_fn(expr const & e);
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/** \brief Given \c e of the form <tt>(...(f a_1) ... a_n)</tt>, return \c n. If \c e is not an application, then return 0. */
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unsigned get_app_num_args(expr const & e);
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/** \brief Return the name of constant, local, metavar */
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inline name const & named_expr_name(expr const & e) { return is_constant(e) ? const_name(e) : mlocal_name(e); }
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// =======================================
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@ -1,7 +1,7 @@
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add_library(library deep_copy.cpp expr_lt.cpp io_state.cpp occurs.cpp
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kernel_bindings.cpp io_state_stream.cpp bin_app.cpp
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resolve_macro.cpp kernel_serializer.cpp max_sharing.cpp
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normalize.cpp shared_environment.cpp module.cpp)
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normalize.cpp shared_environment.cpp module.cpp coercion.cpp)
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# placeholder.cpp fo_unify.cpp hop_match.cpp)
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target_link_libraries(library ${LEAN_LIBS})
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411
src/library/coercion.cpp
Normal file
411
src/library/coercion.cpp
Normal file
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@ -0,0 +1,411 @@
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/*
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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 <utility>
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#include <string>
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#include "util/rb_map.h"
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#include "util/sstream.h"
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#include "kernel/instantiate.h"
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#include "library/coercion.h"
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#include "library/module.h"
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#include "library/kernel_serializer.h"
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namespace lean {
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enum class coercion_class_kind { User, Sort, Fun };
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/**
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\brief A coercion is a mapping between classes.
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We support three kinds of classes: User, Sort, Function.
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*/
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class coercion_class {
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coercion_class_kind m_kind;
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name m_name; // relevant only if m_kind == User
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coercion_class(coercion_class_kind k, name const & n = name()):m_kind(k), m_name(n) {}
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public:
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coercion_class():m_kind(coercion_class_kind::Sort) {}
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static coercion_class mk_user(name n) { return coercion_class(coercion_class_kind::User, n); }
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static coercion_class mk_sort() { return coercion_class(coercion_class_kind::Sort); }
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static coercion_class mk_fun() { return coercion_class(coercion_class_kind::Fun); }
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friend bool operator==(coercion_class const & c1, coercion_class const & c2) { return c1.m_kind == c2.m_kind && c1.m_name == c2.m_name; }
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friend bool operator!=(coercion_class const & c1, coercion_class const & c2) { return !(c1 == c2); }
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coercion_class_kind kind() const { return m_kind; }
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name get_name() const { return m_name; }
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};
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std::ostream & operator<<(std::ostream & out, coercion_class const & cls) {
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switch (cls.kind()) {
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case coercion_class_kind::User: out << cls.get_name(); break;
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case coercion_class_kind::Sort: out << "Sort-class"; break;
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case coercion_class_kind::Fun: out << "Function-class"; break;
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}
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return out;
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}
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struct coercion_class_cmp_fn {
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int operator()(coercion_class const & c1, coercion_class const & c2) const {
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if (c1.kind() != c2.kind())
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return c1.kind() < c2.kind() ? -1 : 1;
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else
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return quick_cmp(c1.get_name(), c2.get_name());
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}
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};
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struct coercion_info {
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expr m_fun;
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expr m_fun_type;
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level_param_names m_level_params;
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unsigned m_num_args;
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coercion_class m_to;
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coercion_info() {}
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coercion_info(expr const & f, expr const & f_type, level_param_names const & ls, unsigned num, coercion_class const & cls):
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m_fun(f), m_fun_type(f_type), m_level_params(ls), m_num_args(num), m_to(cls) {}
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};
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struct coercion_ext : public environment_extension {
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rb_map<name, list<coercion_info>, name_quick_cmp> m_from;
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rb_map<coercion_class, list<name>, coercion_class_cmp_fn> m_to;
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rb_tree<name, name_quick_cmp> m_coercions;
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};
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struct coercion_ext_reg {
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unsigned m_ext_id;
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coercion_ext_reg() { m_ext_id = environment::register_extension(std::make_shared<coercion_ext>()); }
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};
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static coercion_ext_reg g_ext;
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static coercion_ext const & get_extension(environment const & env) {
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return static_cast<coercion_ext const &>(env.get_extension(g_ext.m_ext_id));
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}
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static environment update(environment const & env, coercion_ext const & ext) {
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return env.update(g_ext.m_ext_id, std::make_shared<coercion_ext>(ext));
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}
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// key used for module serialization
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static std::string g_coercion_key = "coerce";
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static void coercion_reader(deserializer & d, module_idx, shared_environment &,
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std::function<void(asynch_update_fn const &)> &,
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std::function<void(delayed_update_fn const &)> & add_delayed_update) {
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name f, C;
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d >> f >> C;
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add_delayed_update([=](environment const & env, io_state const & ios) -> environment {
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return add_coercion(env, f, C, ios);
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});
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}
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register_module_object_reader_fn g_coercion_reader(g_coercion_key, coercion_reader);
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static void check_pi(name const & f, expr const & t) {
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if (!is_pi(t))
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throw exception(sstream() << "invalid coercion, '" << f << "' is not function");
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}
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/** \brief Return true iff args contains Var(0), Var(1), ..., Var(args.size() - 1) */
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static bool check_var_args(buffer<expr> const & args) {
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for (unsigned i = 0; i < args.size(); i++) {
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if (!is_var(args[i]) || var_idx(args[i]) != i)
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return false;
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}
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return true;
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}
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/** \brief Return true iff param_id(levels[i]) == level_params[i] */
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static bool check_levels(levels ls, level_param_names ps) {
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while (!is_nil(ls) && !is_nil(ps)) {
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if (!is_param(head(ls)))
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return false;
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if (param_id(head(ls)) != head(ps))
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return false;
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ls = tail(ls);
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ps = tail(ps);
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}
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return is_nil(ls) && is_nil(ps);
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}
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optional<coercion_class> type_to_coercion_class(expr const & t) {
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if (is_sort(t)) {
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return optional<coercion_class>(coercion_class::mk_sort());
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} else if (is_pi(t)) {
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return optional<coercion_class>(coercion_class::mk_fun());
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} else {
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expr const & C = get_app_fn(t);
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if (is_constant(C))
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return optional<coercion_class>(coercion_class::mk_user(const_name(C)));
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else
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return optional<coercion_class>();
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}
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}
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static void add_coercion(coercion_ext & ext, name const & C, expr const & f, expr const & f_type,
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level_param_names const & ls, unsigned num_args,
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coercion_class const & cls, io_state const & ios);
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static void add_coercion_trans(coercion_ext & ext, io_state const & ios, name const & C,
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level_param_names const & f_level_params, expr const & f, expr const & f_type, unsigned f_num_args,
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level_param_names const & g_level_params, expr g, expr const & g_type, unsigned g_num_args) {
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expr t = f_type;
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buffer<name> f_arg_names;
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buffer<expr> f_arg_types;
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buffer<expr> args;
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unsigned i = f_num_args;
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while (is_pi(t)) {
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f_arg_names.push_back(binding_name(t));
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f_arg_types.push_back(binding_domain(t));
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t = binding_body(t);
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i--;
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args.push_back(mk_var(i));
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}
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expr f_app = apply_beta(f, args.size(), args.data());
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expr D_app = t;
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buffer<expr> g_args;
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expr D_cnst = get_app_args(D_app, g_args);
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if (g_args.size() != g_num_args)
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return;
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g_args.push_back(f_app);
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if (length(const_levels(D_cnst)) != length(g_level_params))
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return;
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// C >-> D >-> E
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g = instantiate_params(g, g_level_params, const_levels(D_cnst));
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expr gf = apply_beta(g, g_args.size(), g_args.data());
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expr gf_type = g_type;
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while (is_pi(gf_type))
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gf_type = binding_body(gf_type);
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coercion_class new_cls = *type_to_coercion_class(gf_type);
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gf_type = instantiate(instantiate_params(gf_type, g_level_params, const_levels(D_cnst)), g_args.size(), g_args.data());
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i = f_arg_types.size();
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while (i > 0) {
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--i;
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gf = mk_lambda(f_arg_names[i], f_arg_types[i], gf);
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gf_type = mk_pi(f_arg_names[i], f_arg_types[i], gf_type);
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}
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add_coercion(ext, C, gf, gf_type, f_level_params, f_num_args, new_cls, ios);
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}
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static void add_coercion_trans_to(coercion_ext & ext, name const & C, expr const & f, expr const & f_type,
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level_param_names const & ls, unsigned num_args,
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io_state const & ios) {
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// apply transitivity using ext.m_to
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coercion_class C_cls = coercion_class::mk_user(C);
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auto it1 = ext.m_to.find(C_cls);
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if (!it1)
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return;
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for (name const & B : *it1) {
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auto it2 = ext.m_from.find(B);
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lean_assert(*it2);
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for (coercion_info const & info : *it2) {
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if (info.m_to == C_cls) {
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// B >-> C >-> D
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add_coercion_trans(ext, ios, B,
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info.m_level_params, info.m_fun, info.m_fun_type, info.m_num_args,
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ls, f, f_type, num_args);
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break;
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}
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}
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}
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}
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static void add_coercion_trans_from(coercion_ext & ext, name const & C, expr const & f, expr const & f_type,
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level_param_names const & ls, unsigned num_args,
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coercion_class const & cls, io_state const & ios) {
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// apply transitivity using ext.m_from
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if (cls.kind() != coercion_class_kind::User)
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return; // nothing to do Sort and Fun classes are terminal
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name const & D = cls.get_name();
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auto it = ext.m_from.find(D);
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if (!it)
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return;
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for (coercion_info const & D_info : *it) {
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// C >-> D >-> E
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add_coercion_trans(ext, ios, C,
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ls, f, f_type, num_args,
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D_info.m_level_params, D_info.m_fun, D_info.m_fun_type, D_info.m_num_args);
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}
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}
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// Add entry (D, C) to ext.m_to
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static void update_to(coercion_ext & ext, coercion_class const & D, name const & C) {
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auto it = ext.m_to.find(D);
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if (it) {
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ext.m_to.insert(D, list<name>(C, *it));
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} else {
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ext.m_to.insert(D, list<name>(C));
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}
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}
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static void add_coercion(coercion_ext & ext, name const & C, expr const & f, expr const & f_type,
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level_param_names const & ls, unsigned num_args,
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coercion_class const & cls, io_state const & ios) {
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if (cls.kind() == coercion_class_kind::User && C == cls.get_name())
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return;
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auto it = ext.m_from.find(C);
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if (!it) {
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list<coercion_info> infos(coercion_info(f, f_type, ls, num_args, cls));
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ext.m_from.insert(C, infos);
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update_to(ext, cls, C);
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} else {
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list<coercion_info> infos = *it;
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bool found = false;
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for_each(infos, [&](coercion_info const & info) {
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if (info.m_to == cls)
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ios.get_diagnostic_channel() << "replacing the coercion from '" << C << "' to '" << cls << "'";
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if (is_constant(info.m_fun))
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ext.m_coercions.erase(const_name(info.m_fun));
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found = true;
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});
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if (found)
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infos = filter(infos, [&](coercion_info const & info) { return info.m_to != cls; });
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infos = list<coercion_info>(coercion_info(f, f_type, ls, num_args, cls), infos);
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ext.m_from.insert(C, infos);
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if (!found)
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update_to(ext, cls, C);
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}
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if (is_constant(f))
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ext.m_coercions.insert(const_name(f));
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}
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static environment add_coercion(environment env, name const & C, expr const & f, expr const & f_type,
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level_param_names const & ls, unsigned num_args,
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coercion_class const & cls, io_state const & ios) {
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coercion_ext ext = get_extension(env);
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add_coercion_trans_to(ext, C, f, f_type, ls, num_args, ios);
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add_coercion_trans_from(ext, C, f, f_type, ls, num_args, cls, ios);
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add_coercion(ext, C, f, f_type, ls, num_args, cls, ios);
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name const & f_name = const_name(f);
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env = add(env, g_coercion_key, [=](serializer & s) {
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s << f_name << C;
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});
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return update(env, ext);
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}
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environment add_coercion(environment const & env, name const & f, name const & C, io_state const & ios) {
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declaration d = env.get(f);
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unsigned num = 0;
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buffer<expr> args;
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expr t = d.get_type();
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check_pi(f, t);
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while (true) {
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args.clear();
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expr const & C_fn = get_app_rev_args(binding_domain(t), args);
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if (is_constant(C_fn) &&
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const_name(C_fn) == C &&
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num == args.size() &&
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check_var_args(args) &&
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check_levels(const_levels(C_fn), d.get_params())) {
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expr fn = mk_constant(f, const_levels(C_fn));
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optional<coercion_class> cls = type_to_coercion_class(binding_body(t));
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if (!cls)
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throw exception(sstream() << "invalid coercion, '" << f << "' does not have the expected type to be used as a coercion");
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else if (cls->kind() == coercion_class_kind::User && cls->get_name() == C)
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throw exception(sstream() << "invalid coercion, '" << f << "' is a coercion from '" << C << "' on itself");
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return add_coercion(env, C, fn, d.get_type(), d.get_params(), num, *cls, ios);
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}
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t = binding_body(t);
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num++;
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check_pi(f, t);
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}
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}
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environment add_coercion(environment const & env, name const & f, io_state const & ios) {
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declaration d = env.get(f);
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expr t = d.get_type();
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check_pi(f, t);
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while (is_pi(binding_body(t)))
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t = binding_body(t);
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expr C = get_app_fn(binding_domain(t));
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if (!is_constant(C))
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throw exception(sstream() << "invalid coercion, '" << f << "' does not have the expected type to be used as a coercion");
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return add_coercion(env, f, const_name(C), ios);
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}
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bool is_coercion(environment const & env, expr const & f) {
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if (is_constant(f)) {
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coercion_ext const & ext = get_extension(env);
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return ext.m_coercions.contains(const_name(f));
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} else {
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return false;
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}
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}
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bool has_coercions_from(environment const & env, name const & C) {
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coercion_ext const & ext = get_extension(env);
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return ext.m_from.contains(C);
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}
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bool has_coercions_from(environment const & env, expr const & C) {
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expr const & C_fn = get_app_fn(C);
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if (!is_constant(C_fn))
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return false;
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coercion_ext const & ext = get_extension(env);
|
||||
auto it = ext.m_from.find(const_name(C_fn));
|
||||
if (!it)
|
||||
return false;
|
||||
list<coercion_info> const & cs = *it;
|
||||
return
|
||||
head(cs).m_num_args == get_app_num_args(C) &&
|
||||
length(head(cs).m_level_params) == length(const_levels(C_fn));
|
||||
}
|
||||
|
||||
bool has_coercions_to(environment const & env, name const & D) {
|
||||
coercion_ext const & ext = get_extension(env);
|
||||
return ext.m_to.contains(coercion_class::mk_user(D));
|
||||
}
|
||||
|
||||
bool has_coercions_to(environment const & env, expr const & D) {
|
||||
expr const & D_fn = get_app_fn(D);
|
||||
return is_constant(D_fn) && has_coercions_to(env, const_name(D_fn));
|
||||
}
|
||||
|
||||
optional<expr> get_coercion(environment const & env, expr const & C, coercion_class const & D) {
|
||||
buffer<expr> args;
|
||||
expr const & C_fn = get_app_rev_args(C, args);
|
||||
if (!is_constant(C_fn))
|
||||
return none_expr();
|
||||
coercion_ext const & ext = get_extension(env);
|
||||
auto it = ext.m_from.find(const_name(C_fn));
|
||||
if (!it)
|
||||
return none_expr();
|
||||
for (coercion_info const & info : *it) {
|
||||
if (info.m_to == D && info.m_num_args == args.size() && length(info.m_level_params) == length(const_levels(C_fn))) {
|
||||
expr f = instantiate_params(info.m_fun, info.m_level_params, const_levels(C_fn));
|
||||
return some_expr(apply_beta(f, args.size(), args.data()));
|
||||
}
|
||||
}
|
||||
return none_expr();
|
||||
}
|
||||
|
||||
optional<expr> get_coercion(environment const & env, expr const & C, name const & D) {
|
||||
return get_coercion(env, C, coercion_class::mk_user(D));
|
||||
}
|
||||
|
||||
optional<expr> get_coercion_to_sort(environment const & env, expr const & C) {
|
||||
return get_coercion(env, C, coercion_class::mk_sort());
|
||||
}
|
||||
|
||||
optional<expr> get_coercion_to_fun(environment const & env, expr const & C) {
|
||||
return get_coercion(env, C, coercion_class::mk_fun());
|
||||
}
|
||||
|
||||
bool get_user_coercions(environment const & env, expr const & C, buffer<std::pair<expr, name>> & result) {
|
||||
buffer<expr> args;
|
||||
expr const & C_fn = get_app_rev_args(C, args);
|
||||
if (!is_constant(C_fn))
|
||||
return false;
|
||||
coercion_ext const & ext = get_extension(env);
|
||||
auto it = ext.m_from.find(const_name(C_fn));
|
||||
if (!it)
|
||||
return false;
|
||||
bool r = false;
|
||||
for (coercion_info const & info : *it) {
|
||||
if (info.m_to.kind() == coercion_class_kind::User &&
|
||||
info.m_num_args == args.size() &&
|
||||
length(info.m_level_params) == length(const_levels(C_fn))) {
|
||||
expr f = instantiate_params(info.m_fun, info.m_level_params, const_levels(C_fn));
|
||||
expr c = apply_beta(f, args.size(), args.data());
|
||||
result.emplace_back(c, info.m_to.get_name());
|
||||
r = true;
|
||||
}
|
||||
}
|
||||
return r;
|
||||
}
|
||||
}
|
||||
|
|
@ -5,7 +5,11 @@ Released under Apache 2.0 license as described in the file LICENSE.
|
|||
Author: Leonardo de Moura
|
||||
*/
|
||||
#pragma once
|
||||
#include <utility>
|
||||
#include "kernel/environment.h"
|
||||
#include "library/expr_pair.h"
|
||||
#include "library/io_state.h"
|
||||
|
||||
namespace lean {
|
||||
/**
|
||||
\brief Add an new coercion in the given environment.
|
||||
|
|
@ -28,11 +32,32 @@ namespace lean {
|
|||
{l1 ... lk} Pi (x1 : A1) ... (xn : An) (y: C.{l1 ... lk} x1 ... xn), Type.{L}
|
||||
|
||||
\pre \c f is a constant defined in \c env.
|
||||
|
||||
\remark \c ios is used to report warning messages.
|
||||
*/
|
||||
environment add_coercion(environment const & env, expr const & f);
|
||||
environment add_coercion(environment const & env, name & f, io_state const & ios);
|
||||
environment add_coercion(environment const & env, name const & f, name const & C, io_state const & ios);
|
||||
bool is_coercion(environment const & env, expr const & f);
|
||||
list<expr_pair> get_coercions(environment const & env, expr const & from, expr const & from_type);
|
||||
optional<expr> get_coercion(environment const & env, expr const & from, expr const & from_type, expr const & to_type);
|
||||
optional<expr> get_coercion_to_sort(environment const & env, expr const & from, expr const & from_type);
|
||||
optional<expr> get_coercion_to_fun(environment const & env, expr const & from, expr const & from_type);
|
||||
/** \brief Return true iff the given environment has coercions from a user-class named \c C. */
|
||||
bool has_coercions_from(environment const & env, name const & C);
|
||||
bool has_coercions_from(environment const & env, expr const & C);
|
||||
/** \brief Return true iff the given environment has coercions to a user-class named \c D. */
|
||||
bool has_coercions_to(environment const & env, name const & D);
|
||||
bool has_coercions_to(environment const & env, expr const & D);
|
||||
/**
|
||||
\brief Return a coercion (if it exists) from (C_name.{l1 lk} t_1 ... t_n) to the class named D.
|
||||
The coercion is a unary function that takes a term of type (C_name.{l1 lk} t_1 ... t_n) and returns
|
||||
and element of type (D.{L_1 L_o} s_1 ... s_m)
|
||||
*/
|
||||
optional<expr> get_coercion(environment const & env, expr const & C, name const & D);
|
||||
optional<expr> get_coercion_to_sort(environment const & env, expr const & C);
|
||||
optional<expr> get_coercion_to_fun(environment const & env, expr const & C);
|
||||
/**
|
||||
\brief Return all user coercions C >-> D for the type C of the form (C_name.{l1 ... lk} t_1 ... t_n)
|
||||
The result is a pair (coercion, user-class D), and is stored in the result buffer \c result.
|
||||
The Boolean result is true if at least one pair is added to \c result.
|
||||
|
||||
\remark The most recent coercions occur first.
|
||||
*/
|
||||
bool get_user_coercions(environment const & env, expr const & C, buffer<std::pair<expr, name>> & result);
|
||||
}
|
||||
|
|
|
|||
Loading…
Reference in a new issue