lean4-htt/src/bindings/lua/expr.cpp
Leonardo de Moura feeb6d9105 feat(bindings/lua): add goal object to Lua API
Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>
2013-11-25 20:51:47 -08:00

480 lines
16 KiB
C++

/*
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 <sstream>
#include <lua.hpp>
#include <utility>
#include "util/debug.h"
#include "util/name.h"
#include "util/buffer.h"
#include "util/sexpr/options.h"
#include "util/sstream.h"
#include "kernel/expr.h"
#include "kernel/instantiate.h"
#include "kernel/abstract.h"
#include "kernel/formatter.h"
#include "kernel/for_each_fn.h"
#include "kernel/free_vars.h"
#include "kernel/occurs.h"
#include "kernel/metavar.h"
#include "library/expr_lt.h"
#include "library/arith/nat.h"
#include "library/arith/int.h"
#include "library/arith/real.h"
#include "bindings/lua/util.h"
#include "bindings/lua/name.h"
#include "bindings/lua/options.h"
#include "bindings/lua/level.h"
#include "bindings/lua/local_context.h"
#include "bindings/lua/formatter.h"
#include "bindings/lua/numerics.h"
namespace lean {
DECL_UDATA(expr)
expr & to_nonnull_expr(lua_State * L, int idx) {
expr & r = to_expr(L, idx);
if (!r)
throw exception("non-null Lean expression expected");
return r;
}
expr & to_app(lua_State * L, int idx) {
expr & r = to_nonnull_expr(L, idx);
if (!is_app(r))
throw exception("Lean application expression expected");
return r;
}
static int expr_tostring(lua_State * L) {
std::ostringstream out;
expr & e = to_expr(L, 1);
if (e) {
formatter fmt = get_global_formatter(L);
options opts = get_global_options(L);
out << mk_pair(fmt(to_expr(L, 1), opts), opts);
} else {
out << "<null-expr>";
}
lua_pushstring(L, out.str().c_str());
return 1;
}
static int expr_eq(lua_State * L) {
lua_pushboolean(L, to_expr(L, 1) == to_expr(L, 2));
return 1;
}
static int expr_lt(lua_State * L) {
lua_pushboolean(L, to_expr(L, 1) < to_expr(L, 2));
return 1;
}
static int expr_mk_constant(lua_State * L) {
return push_expr(L, mk_constant(to_name_ext(L, 1)));
}
static int expr_mk_var(lua_State * L) {
return push_expr(L, mk_var(luaL_checkinteger(L, 1)));
}
static int expr_mk_app(lua_State * L) {
int nargs = lua_gettop(L);
if (nargs < 2)
throw exception("application must have at least two arguments");
buffer<expr> args;
for (int i = 1; i <= nargs; i++)
args.push_back(to_nonnull_expr(L, i));
return push_expr(L, mk_app(args));
}
static int expr_mk_eq(lua_State * L) {
return push_expr(L, mk_eq(to_nonnull_expr(L, 1), to_nonnull_expr(L, 2)));
}
static int expr_mk_lambda(lua_State * L) {
return push_expr(L, mk_lambda(to_name_ext(L, 1), to_nonnull_expr(L, 2), to_nonnull_expr(L, 3)));
}
static int expr_mk_pi(lua_State * L) {
return push_expr(L, mk_pi(to_name_ext(L, 1), to_nonnull_expr(L, 2), to_nonnull_expr(L, 3)));
}
static int expr_mk_arrow(lua_State * L) {
return push_expr(L, mk_arrow(to_nonnull_expr(L, 1), to_nonnull_expr(L, 2)));
}
static int expr_mk_let(lua_State * L) {
int nargs = lua_gettop(L);
if (nargs == 3)
return push_expr(L, mk_let(to_name_ext(L, 1), expr(), to_nonnull_expr(L, 2), to_nonnull_expr(L, 3)));
else
return push_expr(L, mk_let(to_name_ext(L, 1), to_nonnull_expr(L, 2), to_nonnull_expr(L, 3), to_nonnull_expr(L, 4)));
}
static expr get_expr_from_table(lua_State * L, int t, int i) {
lua_pushvalue(L, t); // push table to the top
lua_pushinteger(L, i);
lua_gettable(L, -2);
expr r = to_nonnull_expr(L, -1);
lua_pop(L, 2); // remove table and value
return r;
}
// t is a table of pairs {{a1, b1}, ..., {ak, bk}}
// Each ai and bi is an expression
static std::pair<expr, expr> get_expr_pair_from_table(lua_State * L, int t, int i) {
lua_pushvalue(L, t); // push table on the top
lua_pushinteger(L, i);
lua_gettable(L, -2); // now table {ai, bi} is on the top
if (!lua_istable(L, -1) || objlen(L, -1) != 2)
throw exception("arg #1 must be of the form '{{expr, expr}, ...}'");
expr ai = get_expr_from_table(L, -1, 1);
expr bi = get_expr_from_table(L, -1, 2);
lua_pop(L, 2); // pop table {ai, bi} and t from stack
return mk_pair(ai, bi);
}
typedef expr (*MkAbst1)(expr const & n, expr const & t, expr const & b);
typedef expr (*MkAbst2)(name const & n, expr const & t, expr const & b);
template<MkAbst1 F1, MkAbst2 F2>
int expr_abst(lua_State * L) {
int nargs = lua_gettop(L);
if (nargs < 2)
throw exception("function must have at least 2 arguments");
if (nargs == 2) {
if (!lua_istable(L, 1))
throw exception("function expects arg #1 to be of the form '{{expr, expr}, ...}'");
int len = objlen(L, 1);
if (len == 0)
throw exception("function expects arg #1 to be a non-empty table");
expr r = to_nonnull_expr(L, 2);
for (int i = len; i >= 1; i--) {
auto p = get_expr_pair_from_table(L, 1, i);
r = F1(p.first, p.second, r);
}
return push_expr(L, r);
} else {
if (nargs % 2 == 0)
throw exception("function must have an odd number of arguments");
expr r = to_nonnull_expr(L, nargs);
for (int i = nargs - 1; i >= 1; i-=2) {
if (is_expr(L, i - 1))
r = F1(to_nonnull_expr(L, i - 1), to_nonnull_expr(L, i), r);
else
r = F2(to_name_ext(L, i - 1), to_nonnull_expr(L, i), r);
}
return push_expr(L, r);
}
}
static int expr_fun(lua_State * L) { return expr_abst<Fun, Fun>(L); }
static int expr_pi(lua_State * L) { return expr_abst<Pi, Pi>(L); }
static int expr_let(lua_State * L) { return expr_abst<Let, Let>(L); }
static int expr_type(lua_State * L) {
int nargs = lua_gettop(L);
if (nargs == 0)
return push_expr(L, Type());
else
return push_expr(L, Type(to_level(L, 1)));
}
static int expr_mk_metavar(lua_State * L) {
int nargs = lua_gettop(L);
if (nargs == 1)
return push_expr(L, mk_metavar(to_name_ext(L, 1)));
else
return push_expr(L, mk_metavar(to_name_ext(L, 1), to_local_context(L, 2)));
}
static int expr_is_null(lua_State * L) {
lua_pushboolean(L, !to_expr(L, 1));
return 1;
}
static int expr_get_kind(lua_State * L) {
lua_pushinteger(L, static_cast<int>(to_nonnull_expr(L, 1).kind()));
return 1;
}
#define EXPR_PRED(P) \
static int expr_ ## P(lua_State * L) { \
lua_pushboolean(L, P(to_nonnull_expr(L, 1))); \
return 1; \
}
EXPR_PRED(is_constant)
EXPR_PRED(is_var)
EXPR_PRED(is_app)
EXPR_PRED(is_eq)
EXPR_PRED(is_lambda)
EXPR_PRED(is_pi)
EXPR_PRED(is_abstraction)
EXPR_PRED(is_let)
EXPR_PRED(is_value)
EXPR_PRED(is_metavar)
EXPR_PRED(has_free_vars)
EXPR_PRED(closed)
EXPR_PRED(has_metavar)
/**
\brief Iterator (closure base function) for application args. See \c expr_args
*/
static int expr_next_arg(lua_State * L) {
expr & e = to_expr(L, lua_upvalueindex(1));
unsigned i = lua_tointeger(L, lua_upvalueindex(2));
if (i >= num_args(e)) {
lua_pushnil(L);
} else {
lua_pushinteger(L, i + 1);
lua_replace(L, lua_upvalueindex(2)); // update closure
push_expr(L, arg(e, i));
}
return 1;
}
static int expr_args(lua_State * L) {
expr & e = to_app(L, 1);
push_expr(L, e); // upvalue(1): expr
lua_pushinteger(L, 0); // upvalue(2): index
lua_pushcclosure(L, &safe_function<expr_next_arg>, 2); // create closure with 2 upvalues
return 1;
}
static int expr_num_args(lua_State * L) {
lua_pushinteger(L, num_args(to_app(L, 1)));
return 1;
}
static int expr_arg(lua_State * L) {
expr & e = to_app(L, 1);
int i = luaL_checkinteger(L, 2);
if (i >= static_cast<int>(num_args(e)) || i < 0)
throw exception(sstream() << "invalid application argument #" << i << ", application has " << num_args(e) << " arguments");
return push_expr(L, arg(e, i));
}
static int expr_fields(lua_State * L) {
expr & e = to_nonnull_expr(L, 1);
switch (e.kind()) {
case expr_kind::Var: lua_pushinteger(L, var_idx(e)); return 1;
case expr_kind::Constant: return push_name(L, const_name(e));
case expr_kind::Type: return push_level(L, ty_level(e));
case expr_kind::Value:
if (is_nat_value(e)) {
return push_mpz(L, nat_value_numeral(e));
} else if (is_int_value(e)) {
return push_mpz(L, int_value_numeral(e));
} else if (is_real_value(e)) {
return push_mpq(L, real_value_numeral(e));
} else {
return 0;
}
case expr_kind::App: lua_pushinteger(L, num_args(e)); expr_args(L); return 2;
case expr_kind::Eq: push_expr(L, eq_lhs(e)); push_expr(L, eq_rhs(e)); return 2;
case expr_kind::Lambda:
case expr_kind::Pi: push_name(L, abst_name(e)); push_expr(L, abst_domain(e)); push_expr(L, abst_body(e)); return 3;
case expr_kind::Let: push_name(L, let_name(e)); push_expr(L, let_type(e)); push_expr(L, let_value(e)); push_expr(L, let_body(e)); return 4;
case expr_kind::MetaVar: push_name(L, metavar_name(e)); push_local_context(L, metavar_lctx(e)); return 2;
}
lean_unreachable(); // LCOV_EXCL_LINE
return 0; // LCOV_EXCL_LINE
}
static int expr_for_each(lua_State * L) {
expr & e = to_nonnull_expr(L, 1); // expr
luaL_checktype(L, 2, LUA_TFUNCTION); // user-fun
auto f = [&](expr const & a, unsigned offset) {
lua_pushvalue(L, 2); // push user-fun
push_expr(L, a);
lua_pushinteger(L, offset);
pcall(L, 2, 1, 0);
bool r = true;
if (lua_isboolean(L, -1))
r = lua_toboolean(L, -1);
lua_pop(L, 1);
return r;
};
for_each_fn<decltype(f)> proc(f);
proc(e);
return 0;
}
static int expr_has_free_var(lua_State * L) {
int nargs = lua_gettop(L);
if (nargs == 2)
lua_pushboolean(L, has_free_var(to_expr(L, 1), luaL_checkinteger(L, 2)));
else
lua_pushboolean(L, has_free_var(to_expr(L, 1), luaL_checkinteger(L, 2), luaL_checkinteger(L, 3)));
return 1;
}
static int expr_lift_free_vars(lua_State * L) {
int nargs = lua_gettop(L);
if (nargs == 2)
return push_expr(L, lift_free_vars(to_expr(L, 1), luaL_checkinteger(L, 2)));
else
return push_expr(L, lift_free_vars(to_expr(L, 1), luaL_checkinteger(L, 2), luaL_checkinteger(L, 3)));
}
static int expr_lower_free_vars(lua_State * L) {
int nargs = lua_gettop(L);
if (nargs == 2)
return push_expr(L, lower_free_vars(to_expr(L, 1), luaL_checkinteger(L, 2)));
else
return push_expr(L, lower_free_vars(to_expr(L, 1), luaL_checkinteger(L, 2), luaL_checkinteger(L, 3)));
}
// Copy Lua table/array elements to r
static void copy_lua_array(lua_State * L, int tidx, buffer<expr> & r) {
luaL_checktype(L, tidx, LUA_TTABLE);
int n = objlen(L, tidx);
for (int i = 1; i <= n; i++) {
lua_rawgeti(L, tidx, i);
r.push_back(to_expr(L, -1));
lua_pop(L, 1);
}
}
static int expr_instantiate(lua_State * L) {
expr const & e = to_expr(L, 1);
if (is_expr(L, 2)) {
return push_expr(L, instantiate(e, to_expr(L, 2)));
} else {
buffer<expr> s;
copy_lua_array(L, 2, s);
return push_expr(L, instantiate(e, s.size(), s.data()));
}
}
static int expr_abstract(lua_State * L) {
expr const & e = to_expr(L, 1);
if (is_expr(L, 2)) {
expr const & e2 = to_expr(L, 2);
return push_expr(L, abstract(e, 1, &e2));
} else {
buffer<expr> s;
copy_lua_array(L, 2, s);
return push_expr(L, abstract(e, s.size(), s.data()));
}
}
static int expr_occurs(lua_State * L) {
lua_pushboolean(L, occurs(to_expr(L, 1), to_expr(L, 2)));
return 1;
}
static int expr_is_eqp(lua_State * L) {
lua_pushboolean(L, is_eqp(to_expr(L, 1), to_expr(L, 2)));
return 1;
}
static int expr_hash(lua_State * L) {
lua_pushinteger(L, to_expr(L, 1).hash());
return 1;
}
static const struct luaL_Reg expr_m[] = {
{"__gc", expr_gc}, // never throws
{"__tostring", safe_function<expr_tostring>},
{"__eq", safe_function<expr_eq>},
{"__lt", safe_function<expr_lt>},
{"__call", safe_function<expr_mk_app>},
{"kind", safe_function<expr_get_kind>},
{"is_null", safe_function<expr_is_null>},
{"is_var", safe_function<expr_is_var>},
{"is_constant", safe_function<expr_is_constant>},
{"is_app", safe_function<expr_is_app>},
{"is_eq", safe_function<expr_is_eq>},
{"is_lambda", safe_function<expr_is_lambda>},
{"is_pi", safe_function<expr_is_pi>},
{"is_abstraction", safe_function<expr_is_abstraction>},
{"is_let", safe_function<expr_is_let>},
{"is_value", safe_function<expr_is_value>},
{"is_metavar", safe_function<expr_is_metavar>},
{"fields", safe_function<expr_fields>},
{"data", safe_function<expr_fields>},
{"args", safe_function<expr_args>},
{"num_args", safe_function<expr_num_args>},
{"arg", safe_function<expr_arg>},
{"for_each", safe_function<expr_for_each>},
{"has_free_vars", safe_function<expr_has_free_vars>},
{"closed", safe_function<expr_closed>},
{"has_free_var", safe_function<expr_has_free_var>},
{"lift_free_vars", safe_function<expr_lift_free_vars>},
{"lower_free_vars", safe_function<expr_lower_free_vars>},
{"instantiate", safe_function<expr_instantiate>},
{"abstract", safe_function<expr_abstract>},
{"occurs", safe_function<expr_occurs>},
{"has_metavar", safe_function<expr_has_metavar>},
{"is_eqp", safe_function<expr_is_eqp>},
{"hash", safe_function<expr_hash>},
{0, 0}
};
static int mk_nat_value(lua_State * L) {
mpz v = to_mpz_ext(L, 1);
if (v < 0)
throw exception("arg #1 must be non-negative");
return push_expr(L, mk_nat_value(v));
}
static int mk_int_value(lua_State * L) {
return push_expr(L, mk_int_value(to_mpz_ext(L, 1)));
}
static int mk_real_value(lua_State * L) {
return push_expr(L, mk_real_value(to_mpq_ext(L, 1)));
}
void open_expr(lua_State * L) {
luaL_newmetatable(L, expr_mt);
lua_pushvalue(L, -1);
lua_setfield(L, -2, "__index");
setfuncs(L, expr_m, 0);
SET_GLOBAL_FUN(expr_mk_constant, "mk_constant");
SET_GLOBAL_FUN(expr_mk_constant, "Const");
SET_GLOBAL_FUN(expr_mk_var, "mk_var");
SET_GLOBAL_FUN(expr_mk_var, "Var");
SET_GLOBAL_FUN(expr_mk_app, "mk_app");
SET_GLOBAL_FUN(expr_mk_eq, "mk_eq");
SET_GLOBAL_FUN(expr_mk_eq, "Eq");
SET_GLOBAL_FUN(expr_mk_lambda, "mk_lambda");
SET_GLOBAL_FUN(expr_mk_pi, "mk_pi");
SET_GLOBAL_FUN(expr_mk_arrow, "mk_arrow");
SET_GLOBAL_FUN(expr_mk_let, "mk_let");
SET_GLOBAL_FUN(expr_fun, "fun");
SET_GLOBAL_FUN(expr_fun, "Fun");
SET_GLOBAL_FUN(expr_pi, "Pi");
SET_GLOBAL_FUN(expr_let, "Let");
SET_GLOBAL_FUN(expr_type, "mk_type");
SET_GLOBAL_FUN(expr_type, "Type");
SET_GLOBAL_FUN(expr_mk_metavar, "mk_metavar");
SET_GLOBAL_FUN(expr_pred, "is_expr");
SET_GLOBAL_FUN(mk_nat_value, "mk_nat_value");
SET_GLOBAL_FUN(mk_nat_value, "nVal");
SET_GLOBAL_FUN(mk_int_value, "mk_int_value");
SET_GLOBAL_FUN(mk_int_value, "iVal");
SET_GLOBAL_FUN(mk_real_value, "mk_real_value");
SET_GLOBAL_FUN(mk_real_value, "rVal");
lua_newtable(L);
SET_ENUM("Var", expr_kind::Var);
SET_ENUM("Constant", expr_kind::Constant);
SET_ENUM("Type", expr_kind::Type);
SET_ENUM("Value", expr_kind::Value);
SET_ENUM("App", expr_kind::App);
SET_ENUM("Eq", expr_kind::Eq);
SET_ENUM("Lambda", expr_kind::Lambda);
SET_ENUM("Pi", expr_kind::Pi);
SET_ENUM("Let", expr_kind::Let);
SET_ENUM("MetaVar", expr_kind::MetaVar);
lua_setglobal(L, "expr_kind");
}
}