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

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

src/bindings/lua/CMakeLists.txt

@@ -1,3 +1,3 @@
-add_library(lua util.cpp name.cpp numerics.cpp options.cpp sexpr.cpp leanlua_state.cpp)
+add_library(lua util.cpp name.cpp numerics.cpp options.cpp sexpr.cpp format.cpp leanlua_state.cpp)
 target_link_libraries(lua ${LEAN_LIBS})
 

src/bindings/lua/format.cpp

@@ -0,0 +1,140 @@
+/*
+Copyright (c) 2013 Microsoft Corporation. All rights reserved.
+Released under Apache 2.0 license as described in the file LICENSE.
+
+Author: Leonardo de Moura
+*/
+#ifdef LEAN_USE_LUA
+#include <sstream>
+#include <lua.hpp>
+#include <cstring>
+#include "util/debug.h"
+#include "util/sexpr/format.h"
+#include "bindings/lua/util.h"
+#include "bindings/lua/name.h"
+#include "bindings/lua/numerics.h"
+
+namespace lean {
+constexpr char const * format_mt = "format.mt";
+
+int push_format(lua_State * L, format const & e) {
+    void * mem = lua_newuserdata(L, sizeof(format));
+    new (mem) format(e);
+    luaL_getmetatable(L, format_mt);
+    lua_setmetatable(L, -2);
+    return 1;
+}
+
+bool is_format(lua_State * L, int idx) {
+    return testudata(L, idx, format_mt);
+}
+
+format & to_format(lua_State * L, int idx) {
+    return *static_cast<format*>(luaL_checkudata(L, idx, format_mt));
+}
+
+format to_format_elem(lua_State * L, int idx) {
+    if (is_format(L, idx))
+        return to_format(L, idx);
+    else if (lua_isnumber(L, idx))
+        return format(static_cast<int>(lua_tonumber(L, idx)));
+    else if (is_name(L, idx))
+        return format(to_name(L, idx));
+    else if (is_mpz(L, idx))
+        return format(to_mpz(L, idx));
+    else if (is_mpq(L, idx))
+        return format(to_mpq(L, idx));
+    else
+        return format(lua_tostring(L, idx));
+}
+
+static int format_gc(lua_State * L) {
+    to_format(L, 1).~format();
+    return 0;
+}
+
+static int format_tostring(lua_State * L) {
+    std::ostringstream out;
+    out << to_format(L, 1);
+    lua_pushfstring(L, out.str().c_str());
+    return 1;
+}
+
+static int format_concat(lua_State * L) {
+    return push_format(L, compose(to_format_elem(L, 1), to_format_elem(L, 2)));
+}
+
+static int mk_format(lua_State * L) {
+    format r;
+    int nargs = lua_gettop(L);
+    if (nargs == 0) {
+        r = format();
+    } else {
+        int i = nargs;
+        r = to_format_elem(L, i);
+        i--;
+        for (; i >= 1; i--) {
+            r = compose(to_format_elem(L, i), r);
+        }
+    }
+    return push_format(L, r);
+}
+
+static int format_nest(lua_State * L) {
+    return push_format(L, nest(luaL_checkinteger(L, 2), to_format(L, 1)));
+}
+
+static int format_group(lua_State * L) {
+    return push_format(L, group(to_format(L, 1)));
+}
+
+static int format_highlight(lua_State * L) {
+    char const * color_str = luaL_checkstring(L, 2);
+    format::format_color color;
+    if (strcmp(color_str, "red") == 0) {
+        color = format::RED;
+    } else if (strcmp(color_str, "green") == 0) {
+        color = format::GREEN;
+    } else if (strcmp(color_str, "orange") == 0) {
+        color = format::ORANGE;
+    } else if (strcmp(color_str, "blue") == 0) {
+        color = format::BLUE;
+    } else if (strcmp(color_str, "cyan") == 0) {
+        color = format::CYAN;
+    } else if (strcmp(color_str, "grey") == 0) {
+        color = format::GREY;
+    } else {
+        return luaL_error(L, "unknown color '%'", color_str);
+    }
+    return push_format(L, highlight(to_format(L, 1), color));
+}
+
+static int format_line(lua_State * L) { return push_format(L, line()); }
+static int format_space(lua_State * L) { return push_format(L, space()); }
+
+static const struct luaL_Reg format_m[] = {
+    {"__gc",            format_gc}, // never throws
+    {"__tostring",      safe_function<format_tostring>},
+    {"__concat",        safe_function<format_concat>},
+    {"nest",            safe_function<format_nest>},
+    {"group",           safe_function<format_group>},
+    {"highlight",       safe_function<format_highlight>},
+    {0, 0}
+};
+
+void open_format(lua_State * L) {
+    luaL_newmetatable(L, format_mt);
+    lua_pushvalue(L, -1);
+    lua_setfield(L, -2, "__index");
+    setfuncs(L, format_m, 0);
+
+    lua_pushcfunction(L, safe_function<mk_format>);
+    lua_setglobal(L, "format");
+
+    lua_pushcfunction(L, safe_function<format_line>);
+    lua_setglobal(L, "line");
+    lua_pushcfunction(L, safe_function<format_space>);
+    lua_setglobal(L, "space");
+}
+}
+#endif

src/bindings/lua/format.h

@@ -0,0 +1,16 @@
+/*
+Copyright (c) 2013 Microsoft Corporation. All rights reserved.
+Released under Apache 2.0 license as described in the file LICENSE.
+
+Author: Leonardo de Moura
+*/
+#ifdef LEAN_USE_LUA
+#include <lua.hpp>
+namespace lean {
+class format;
+void open_format(lua_State * L);
+bool is_format(lua_State * L, int idx);
+format & to_format(lua_State * L, int idx);
+int push_format(lua_State * L, format const & o);
+}
+#endif

src/bindings/lua/leanlua_state.cpp

@@ -19,6 +19,7 @@ Author: Leonardo de Moura
 #include "bindings/lua/numerics.h"
 #include "bindings/lua/options.h"
 #include "bindings/lua/sexpr.h"
+#include "bindings/lua/format.h"
 
 extern "C" void * lua_realloc(void *, void * q, size_t, size_t new_size) { return lean::realloc(q, new_size); }
 
@@ -37,6 +38,7 @@ struct leanlua_state::imp {
         lean::open_mpq(m_state);
         lean::open_options(m_state);
         lean::open_sexpr(m_state);
+        lean::open_format(m_state);
     }
 
     ~imp() {

tests/lua/format1.lua

@@ -0,0 +1,4 @@
+
+
+f = format(format("hello"):highlight('red'), line(), 1):group() .. space() .. (line() .. format("world")):nest(4)
+print(f)