lean2/src/frontend/frontend.cpp

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/*
Copyright (c) 2013 Microsoft Corporation. All rights reserved.
Released under Apache 2.0 license as described in the file LICENSE.
Author: Leonardo de Moura
*/
#include <atomic>
#include "map.h"
#include "frontend.h"
#include "environment.h"
#include "operator_info.h"
namespace lean {
/**
\brief Create object for tracking notation/operator declarations.
This object is mainly used for pretty printing.
*/
class notation_declaration : public anonymous_object {
operator_info m_op;
name m_name;
public:
notation_declaration(operator_info const & op, name const & n):m_op(op), m_name(n) {}
virtual ~notation_declaration() {}
static char const * g_keyword;
virtual char const * keyword() const { return g_keyword; }
virtual format pp(environment const &) const {
char const * cmd;
switch (m_op.get_fixity()) {
case fixity::Infixl: cmd = "Infixl"; break;
case fixity::Infixr: cmd = "Infixr"; break;
case fixity::Prefix: cmd = "Prefix"; break;
case fixity::Postfix: cmd = "Postfix"; break;
case fixity::Mixfixl: cmd = "Mixfixl"; break;
case fixity::Mixfixr: cmd = "Mixfixr"; break;
case fixity::Mixfixc: cmd = "Mixfixc"; break;
}
format r = highlight_command(format(cmd));
if (m_op.get_precedence() != 0)
r += format{space(), format(m_op.get_precedence())};
for (auto p : m_op.get_op_name_parts())
r += format{space(), format(p)};
r += format{space(), format(m_name)};
return r;
}
};
char const * notation_declaration::g_keyword = "Notation";
/** \brief Implementation of the Lean frontend */
struct frontend::imp {
// Remark: only named objects are stored in the dictionary.
typedef std::unordered_map<name, operator_info, name_hash, name_eq> operator_table;
typedef std::unordered_map<name, unsigned, name_hash, name_eq> implicit_table;
std::atomic<unsigned> m_num_children;
std::shared_ptr<imp> m_parent;
environment m_env;
operator_table m_nud; // nud table for Pratt's parser
operator_table m_led; // led table for Pratt's parser
operator_table m_name_to_operator; // map internal names to operators (this is used for pretty printing)
implicit_table m_implicit_table; // track the number of implicit arguments for a symbol.
bool has_children() const { return m_num_children > 0; }
void inc_children() { m_num_children++; }
void dec_children() { m_num_children--; }
bool has_parent() const { return m_parent != nullptr; }
/** \brief Return the nud operator for the given symbol. */
operator_info find_nud(name const & n) const {
auto it = m_nud.find(n);
if (it != m_nud.end())
return it->second;
else if (has_parent())
return m_parent->find_nud(n);
else
return operator_info();
}
/** \brief Return the led operator for the given symbol. */
operator_info find_led(name const & n) const {
auto it = m_led.find(n);
if (it != m_led.end())
return it->second;
else if (has_parent())
return m_parent->find_led(n);
else
return operator_info();
}
/**
\brief Return true if the given operator is defined in this
frontend object (parent frontends are ignored).
*/
bool defined_here(operator_info const & n, bool led) const {
if (led)
return m_led.find(n.get_op_name()) != m_led.end();
else
return m_nud.find(n.get_op_name()) != m_nud.end();
}
/** \brief Return the led/nud operator for the given symbol. */
operator_info find_op(name const & n, bool led) const {
return led ? find_led(n) : find_nud(n);
}
/** \brief Insert a new led/nud operator. */
void insert_op(operator_info const & op, bool led) {
if (led)
insert(m_led, op.get_op_name(), op);
else
insert(m_nud, op.get_op_name(), op);
}
/** \brief Find the operator that is used as notation for the given internal symbol. */
operator_info find_op_for(name const & n) const {
auto it = m_name_to_operator.find(n);
if (it != m_name_to_operator.end())
return it->second;
else if (has_parent())
return m_parent->find_op_for(n);
else
return operator_info();
}
void diagnostic_msg(char const * msg) {
// TODO
}
void report_op_redefined(operator_info const & old_op, operator_info const & new_op) {
// TODO
}
/** \brief Remove all internal operators that are associated with the given operator symbol (aka notation) */
void remove_bindings(operator_info const & op) {
for (name const & n : op.get_internal_names()) {
if (has_parent() && !is_nil(m_parent->find_op_for(n))) {
// parent has a binding for n... we must hide it.
insert(m_name_to_operator, n, operator_info());
} else {
m_name_to_operator.erase(n);
}
}
}
/** \brief Register the new operator in the tables for parsing and pretty printing. */
void register_new_op(operator_info new_op, name const & n, bool led) {
new_op.add_internal_name(n);
insert_op(new_op, led);
insert(m_name_to_operator, n, new_op);
}
/**
\brief Add a new operator and save information as object.
If the new operator does not conflict with existing operators,
then we just register it.
If it conflicts, there are two options:
1) It is an overload (we just add the internal name \c n as
new option.
2) It is a real conflict, and report the issue in the
diagnostic channel, and override the existing operator (aka notation).
*/
void add_op(operator_info new_op, name const & n, bool led) {
name const & opn = new_op.get_op_name();
operator_info old_op = find_op(opn, led);
if (is_nil(old_op)) {
register_new_op(new_op, n, led);
} else if (old_op == new_op) {
// overload
if (defined_here(old_op, led)) {
old_op.add_internal_name(n);
} else {
// we must copy the operator because it was defined in
// a parent frontend.
new_op = old_op.copy();
register_new_op(new_op, n, led);
}
} else {
report_op_redefined(old_op, new_op);
remove_bindings(old_op);
register_new_op(new_op, n, led);
}
m_env.add_anonymous_object(new notation_declaration(new_op, n));
}
void add_infixl(name const & opn, unsigned precedence, name const & n) {
add_op(infixl(opn, precedence), n, true);
}
void add_infixr(name const & opn, unsigned precedence, name const & n) {
add_op(infixr(opn, precedence), n, true);
}
void add_prefix(name const & opn, unsigned precedence, name const & n) {
add_op(prefix(opn, precedence), n, false);
}
void add_postfix(name const & opn, unsigned precedence, name const & n) {
add_op(postfix(opn, precedence), n, true);
}
imp():
m_num_children(0) {
}
explicit imp(std::shared_ptr<imp> const & parent):
m_num_children(0),
m_parent(parent),
m_env(m_parent->m_env.mk_child()) {
m_parent->inc_children();
}
~imp() {
if (m_parent)
m_parent->dec_children();
}
};
frontend::frontend():
m_imp(new imp()) {
}
frontend::frontend(imp * new_ptr):
m_imp(new_ptr) {
}
frontend::frontend(std::shared_ptr<imp> const & ptr):
m_imp(ptr) {
}
frontend::~frontend() {
}
frontend frontend::mk_child() const {
return frontend(new imp(m_imp));
}
bool frontend::has_children() const {
return m_imp->has_children();
}
bool frontend::has_parent() const {
return m_imp->has_parent();
}
frontend frontend::parent() const {
lean_assert(has_parent());
return frontend(m_imp->m_parent);
}
environment const & frontend::env() const { return m_imp->m_env; }
level frontend::add_uvar(name const & n, level const & l) { return m_imp->m_env.add_uvar(n, l); }
level frontend::add_uvar(name const & n) { return m_imp->m_env.add_uvar(n); }
level frontend::get_uvar(name const & n) const { return m_imp->m_env.get_uvar(n); }
void frontend::add_infixl(name const & opn, unsigned p, name const & n) { m_imp->add_infixl(opn, p, n); }
void frontend::add_infixr(name const & opn, unsigned p, name const & n) { m_imp->add_infixr(opn, p, n); }
void frontend::add_prefix(name const & opn, unsigned p, name const & n) { m_imp->add_prefix(opn, p, n); }
void frontend::add_postfix(name const & opn, unsigned p, name const & n) { m_imp->add_postfix(opn, p, n); }
void frontend::display(std::ostream & out) const { m_imp->m_env.display(out); }
}