lean4-htt/src/library/compiler/rec_fn_macro.cpp

102 lines
3.2 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 <string>
#include "util/sstream.h"
#include "library/kernel_serializer.h"
#include "library/compiler/rec_fn_macro.h"
namespace lean {
static name * g_rec_fn_macro_id = nullptr;
static std::string * g_rec_fn_opcode = nullptr;
name const & get_rec_fn_macro_id() { return *g_rec_fn_macro_id; }
std::string const & get_rec_fn_opcode() { return *g_rec_fn_opcode; }
/** \brief We use a macro to mark recursive function calls. */
class rec_fn_macro_definition_cell : public macro_definition_cell {
name m_name;
void check_macro(expr const & m) const {
if (!is_macro(m) || macro_num_args(m) != 1)
throw exception(sstream() << "invalid recursive function '" << m_name << "' macro, incorrect number of arguments");
}
public:
rec_fn_macro_definition_cell(name const & n):m_name(n) {}
name const & get_rec_fn_name() const { return m_name; }
virtual name get_name() const { return get_rec_fn_macro_id(); }
virtual format pp(formatter const &) const { return format(m_name); }
virtual void display(std::ostream & out) const { out << m_name; }
virtual expr check_type(expr const & m, abstract_type_context &, bool) const {
check_macro(m);
return macro_arg(m, 0);
}
virtual optional<expr> expand(expr const &, abstract_type_context &) const {
return none_expr();
}
virtual void write(serializer & s) const {
s.write_string(get_rec_fn_opcode());
s << m_name;
}
virtual bool operator==(macro_definition_cell const & other) const {
if (auto other_ptr = dynamic_cast<rec_fn_macro_definition_cell const *>(&other)) {
return m_name == other_ptr->m_name;
} else {
return false;
}
}
virtual unsigned hash() const {
return ::lean::hash(m_name.hash(), get_rec_fn_macro_id().hash());
}
};
expr mk_rec_fn_macro(name const & fn_name, expr const & type) {
macro_definition def(new rec_fn_macro_definition_cell(fn_name));
return mk_macro(def, 1, &type);
}
bool is_rec_fn_macro(expr const & e) {
return is_macro(e) && macro_def(e).get_name() == get_rec_fn_macro_id();
}
name const & get_rec_fn_name(expr const & e) {
lean_assert(is_rec_fn_macro(e));
return static_cast<rec_fn_macro_definition_cell const*>(macro_def(e).raw())->get_rec_fn_name();
}
expr const & get_rec_fn_type(expr const & e) {
lean_assert(is_rec_fn_macro(e));
return macro_arg(e, 0);
}
void initialize_rec_fn_macro() {
g_rec_fn_macro_id = new name("rec_fn");
g_rec_fn_opcode = new std::string("RecFn");
register_macro_deserializer(get_rec_fn_opcode(),
[](deserializer & d, unsigned num, expr const * args) {
if (num != 1)
throw corrupted_stream_exception();
name fn;
d >> fn;
return mk_rec_fn_macro(fn, args[0]);
});
}
void finalize_rec_fn_macro() {
delete g_rec_fn_opcode;
delete g_rec_fn_macro_id;
}
}