From 26605b51971d2f899ce55214a86d799a310fd010 Mon Sep 17 00:00:00 2001 From: Matthew Wild Date: Fri, 18 Mar 2022 15:21:25 +0000 Subject: util.table: Backport table.move() from Lua 5.4 One difference is that 5.4 accepts "table-like" values (for this and other table.*() functions), but that would require additional backporting work. --- util-src/table.c | 42 ++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 42 insertions(+) diff --git a/util-src/table.c b/util-src/table.c index 9a9553fc..0756a256 100644 --- a/util-src/table.c +++ b/util-src/table.c @@ -1,11 +1,17 @@ #include #include +#ifndef LUA_MAXINTEGER +#include +#define LUA_MAXINTEGER PTRDIFF_MAX +#endif + static int Lcreate_table(lua_State *L) { lua_createtable(L, luaL_checkinteger(L, 1), luaL_checkinteger(L, 2)); return 1; } +/* COMPAT: w/ Lua pre-5.4 */ static int Lpack(lua_State *L) { unsigned int n_args = lua_gettop(L); lua_createtable(L, n_args, 1); @@ -20,6 +26,40 @@ static int Lpack(lua_State *L) { return 1; } +/* COMPAT: w/ Lua pre-5.4 */ +static int Lmove (lua_State *L) { + lua_Integer f = luaL_checkinteger(L, 2); + lua_Integer e = luaL_checkinteger(L, 3); + lua_Integer t = luaL_checkinteger(L, 4); + + int tt = !lua_isnoneornil(L, 5) ? 5 : 1; /* destination table */ + luaL_checktype(L, 1, LUA_TTABLE); + luaL_checktype(L, tt, LUA_TTABLE); + + if (e >= f) { /* otherwise, nothing to move */ + lua_Integer n, i; + luaL_argcheck(L, f > 0 || e < LUA_MAXINTEGER + f, 3, + "too many elements to move"); + n = e - f + 1; /* number of elements to move */ + luaL_argcheck(L, t <= LUA_MAXINTEGER - n + 1, 4, + "destination wrap around"); + if (t > e || t <= f || (tt != 1 && !lua_compare(L, 1, tt, LUA_OPEQ))) { + for (i = 0; i < n; i++) { + lua_rawgeti(L, 1, f + i); + lua_rawseti(L, tt, t + i); + } + } else { + for (i = n - 1; i >= 0; i--) { + lua_rawgeti(L, 1, f + i); + lua_rawseti(L, tt, t + i); + } + } + } + + lua_pushvalue(L, tt); /* return destination table */ + return 1; +} + int luaopen_util_table(lua_State *L) { #if (LUA_VERSION_NUM > 501) luaL_checkversion(L); @@ -29,5 +69,7 @@ int luaopen_util_table(lua_State *L) { lua_setfield(L, -2, "create"); lua_pushcfunction(L, Lpack); lua_setfield(L, -2, "pack"); + lua_pushcfunction(L, Lmove); + lua_setfield(L, -2, "move"); return 1; } -- cgit v1.2.3