feat(lua): expose environment objects in the Lua bindings

Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>

src/bindings/lua/CMakeLists.txt

@@ -1,5 +1,5 @@
 add_library(lua util.cpp lua_exception.cpp name.cpp numerics.cpp
 options.cpp sexpr.cpp format.cpp level.cpp local_context.cpp expr.cpp
-context.cpp leanlua_state.cpp)
+context.cpp environment.cpp leanlua_state.cpp)
 
 target_link_libraries(lua ${LEAN_LIBS})

src/bindings/lua/environment.cpp

@@ -0,0 +1,132 @@
+/*
+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 "kernel/environment.h"
+#include "bindings/lua/util.h"
+#include "bindings/lua/name.h"
+#include "bindings/lua/level.h"
+#include "bindings/lua/expr.h"
+#include "bindings/lua/context.h"
+
+namespace lean {
+constexpr char const * environment_mt = "environment.mt";
+
+bool is_environment(lua_State * L, int idx) {
+    return testudata(L, idx, environment_mt);
+}
+
+environment & to_environment(lua_State * L, int idx) {
+    return *static_cast<environment*>(luaL_checkudata(L, idx, environment_mt));
+}
+
+static int environment_gc(lua_State * L) {
+    to_environment(L, 1).~environment();
+    return 0;
+}
+
+static int mk_environment(lua_State * L) {
+    void * mem = lua_newuserdata(L, sizeof(environment));
+    new (mem) environment();
+    luaL_getmetatable(L, environment_mt);
+    lua_setmetatable(L, -2);
+    return 1;
+}
+
+static int environment_add_uvar(lua_State * L) {
+    int nargs = lua_gettop(L);
+    if (nargs == 2)
+        to_environment(L, 1).add_uvar(to_name_ext(L, 2));
+    else
+        to_environment(L, 1).add_uvar(to_name_ext(L, 2), to_level(L, 3));
+    return 0;
+}
+
+static int environment_is_ge(lua_State * L) {
+    lua_pushboolean(L, to_environment(L, 1).is_ge(to_level(L, 2), to_level(L, 3)));
+    return 1;
+}
+
+static int environment_get_uvar(lua_State * L) {
+    return push_level(L, to_environment(L, 1).get_uvar(to_name_ext(L, 2)));
+}
+
+static int environment_add_definition(lua_State * L) {
+    int nargs = lua_gettop(L);
+    if (nargs == 3) {
+        to_environment(L, 1).add_definition(to_name_ext(L, 2), to_nonnull_expr(L, 3));
+    } else if (nargs == 4) {
+        if (is_expr(L, 4))
+            to_environment(L, 1).add_definition(to_name_ext(L, 2), to_nonnull_expr(L, 3), to_nonnull_expr(L, 4));
+        else
+            to_environment(L, 1).add_definition(to_name_ext(L, 2), to_nonnull_expr(L, 3), lua_toboolean(L, 4));
+    } else {
+        to_environment(L, 1).add_definition(to_name_ext(L, 2), to_nonnull_expr(L, 3), to_nonnull_expr(L, 4), lua_toboolean(L, 5));
+    }
+    return 0;
+}
+
+static int environment_add_theorem(lua_State * L) {
+    to_environment(L, 1).add_theorem(to_name_ext(L, 2), to_nonnull_expr(L, 3), to_nonnull_expr(L, 4));
+    return 0;
+}
+
+static int environment_add_var(lua_State * L) {
+    to_environment(L, 1).add_var(to_name_ext(L, 2), to_nonnull_expr(L, 3));
+    return 0;
+}
+
+static int environment_add_axiom(lua_State * L) {
+    to_environment(L, 1).add_axiom(to_name_ext(L, 2), to_nonnull_expr(L, 3));
+    return 0;
+}
+
+static int environment_check_type(lua_State * L) {
+    int nargs = lua_gettop(L);
+    if (nargs == 2)
+        return push_expr(L, to_environment(L, 1).infer_type(to_nonnull_expr(L, 2)));
+    else
+        return push_expr(L, to_environment(L, 1).infer_type(to_nonnull_expr(L, 2), to_context(L, 3)));
+}
+
+static int environment_normalize(lua_State * L) {
+    int nargs = lua_gettop(L);
+    if (nargs == 2)
+        return push_expr(L, to_environment(L, 1).normalize(to_nonnull_expr(L, 2)));
+    else
+        return push_expr(L, to_environment(L, 1).normalize(to_nonnull_expr(L, 2), to_context(L, 3)));
+}
+
+static int environment_pred(lua_State * L) {
+    lua_pushboolean(L, is_environment(L, 1));
+    return 1;
+}
+
+static const struct luaL_Reg environment_m[] = {
+    {"__gc",           environment_gc}, // never throws
+    {"add_uvar",       safe_function<environment_add_uvar>},
+    {"is_ge",          safe_function<environment_is_ge>},
+    {"get_uvar",       safe_function<environment_get_uvar>},
+    {"add_definition", safe_function<environment_add_definition>},
+    {"add_theorem",    safe_function<environment_add_theorem>},
+    {"add_var",        safe_function<environment_add_var>},
+    {"add_axiom",      safe_function<environment_add_axiom>},
+    {"check_type",     safe_function<environment_check_type>},
+    {"normalize",      safe_function<environment_normalize>},
+    {0, 0}
+};
+
+void open_environment(lua_State * L) {
+    luaL_newmetatable(L, environment_mt);
+    lua_pushvalue(L, -1);
+    lua_setfield(L, -2, "__index");
+    setfuncs(L, environment_m, 0);
+
+    set_global_function<mk_environment>(L, "environment");
+    set_global_function<environment_pred>(L, "is_environment");
+}
+}

src/bindings/lua/environment.h

@@ -0,0 +1,15 @@
+/*
+Copyright (c) 2013 Microsoft Corporation. All rights reserved.
+Released under Apache 2.0 license as described in the file LICENSE.
+
+Author: Leonardo de Moura
+*/
+#pragma once
+#include <lua.hpp>
+namespace lean {
+class environment;
+void open_environment(lua_State * L);
+bool is_environment(lua_State * L, int idx);
+environment & to_environment(lua_State * L, int idx);
+int push_environment(lua_State * L, environment const & o);
+}

src/bindings/lua/leanlua_state.cpp

@@ -22,6 +22,7 @@ Author: Leonardo de Moura
 #include "bindings/lua/local_context.h"
 #include "bindings/lua/expr.h"
 #include "bindings/lua/context.h"
+#include "bindings/lua/environment.h"
 #include "bindings/lua/lean.lua"
 
 extern "C" void * lua_realloc(void *, void * q, size_t, size_t new_size) { return lean::realloc(q, new_size); }
@@ -50,6 +51,7 @@ struct leanlua_state::imp {
         lean::open_local_context(m_state);
         lean::open_expr(m_state);
         lean::open_context(m_state);
+        lean::open_environment(m_state);
         dostring(g_leanlua_extra);
     }
 

tests/lua/env1.lua

@@ -0,0 +1,9 @@
+e = environment()
+assert(is_environment(e))
+e:add_uvar("M")
+print(e:get_uvar("M"))
+e:add_var("N", Type())
+N, M = Consts("N M")
+e:add_var("a", N)
+x, a = Consts("x, a")
+print(e:check_type(fun(x, M, a)))