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** $Id: ltablib.c,v 1.38.1.3 2008/02/14 16:46:58 roberto Exp $
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** Library for Table Manipulation
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** See Copyright Notice in lua.h
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#define aux_getn(L,n) (luaL_checktype(L, n, LUA_TTABLE), luaL_getn(L, n))
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static int foreachi (lua_State *L) {
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int n = aux_getn(L, 1);
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luaL_checktype(L, 2, LUA_TFUNCTION);
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for (i=1; i <= n; i++) {
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lua_pushvalue(L, 2); /* function */
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lua_pushinteger(L, i); /* 1st argument */
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lua_rawgeti(L, 1, i); /* 2nd argument */
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if (!lua_isnil(L, -1))
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lua_pop(L, 1); /* remove nil result */
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static int foreach (lua_State *L) {
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luaL_checktype(L, 1, LUA_TTABLE);
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luaL_checktype(L, 2, LUA_TFUNCTION);
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lua_pushnil(L); /* first key */
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while (lua_next(L, 1)) {
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lua_pushvalue(L, 2); /* function */
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lua_pushvalue(L, -3); /* key */
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lua_pushvalue(L, -3); /* value */
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if (!lua_isnil(L, -1))
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lua_pop(L, 2); /* remove value and result */
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static int maxn (lua_State *L) {
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luaL_checktype(L, 1, LUA_TTABLE);
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lua_pushnil(L); /* first key */
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while (lua_next(L, 1)) {
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lua_pop(L, 1); /* remove value */
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if (lua_type(L, -1) == LUA_TNUMBER) {
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lua_Number v = lua_tonumber(L, -1);
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lua_pushnumber(L, max);
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static int getn (lua_State *L) {
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lua_pushinteger(L, aux_getn(L, 1));
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static int setn (lua_State *L) {
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luaL_checktype(L, 1, LUA_TTABLE);
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luaL_setn(L, 1, luaL_checkint(L, 2));
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luaL_error(L, LUA_QL("setn") " is obsolete");
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static int tinsert (lua_State *L) {
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int e = aux_getn(L, 1) + 1; /* first empty element */
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int pos; /* where to insert new element */
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switch (lua_gettop(L)) {
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case 2: { /* called with only 2 arguments */
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pos = e; /* insert new element at the end */
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pos = luaL_checkint(L, 2); /* 2nd argument is the position */
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if (pos > e) e = pos; /* `grow' array if necessary */
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for (i = e; i > pos; i--) { /* move up elements */
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lua_rawgeti(L, 1, i-1);
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lua_rawseti(L, 1, i); /* t[i] = t[i-1] */
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return luaL_error(L, "wrong number of arguments to " LUA_QL("insert"));
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luaL_setn(L, 1, e); /* new size */
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lua_rawseti(L, 1, pos); /* t[pos] = v */
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static int tremove (lua_State *L) {
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int e = aux_getn(L, 1);
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int pos = luaL_optint(L, 2, e);
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if (!(1 <= pos && pos <= e)) /* position is outside bounds? */
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return 0; /* nothing to remove */
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luaL_setn(L, 1, e - 1); /* t.n = n-1 */
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lua_rawgeti(L, 1, pos); /* result = t[pos] */
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for ( ;pos<e; pos++) {
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lua_rawgeti(L, 1, pos+1);
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lua_rawseti(L, 1, pos); /* t[pos] = t[pos+1] */
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lua_rawseti(L, 1, e); /* t[e] = nil */
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static void addfield (lua_State *L, luaL_Buffer *b, int i) {
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lua_rawgeti(L, 1, i);
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if (!lua_isstring(L, -1))
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luaL_error(L, "invalid value (%s) at index %d in table for "
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LUA_QL("concat"), luaL_typename(L, -1), i);
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static int tconcat (lua_State *L) {
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const char *sep = luaL_optlstring(L, 2, "", &lsep);
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luaL_checktype(L, 1, LUA_TTABLE);
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i = luaL_optint(L, 3, 1);
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last = luaL_opt(L, luaL_checkint, 4, luaL_getn(L, 1));
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luaL_buffinit(L, &b);
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for (; i < last; i++) {
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luaL_addlstring(&b, sep, lsep);
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if (i == last) /* add last value (if interval was not empty) */
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** {======================================================
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** (based on `Algorithms in MODULA-3', Robert Sedgewick;
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** Addison-Wesley, 1993.)
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static void set2 (lua_State *L, int i, int j) {
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lua_rawseti(L, 1, i);
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lua_rawseti(L, 1, j);
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static int sort_comp (lua_State *L, int a, int b) {
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if (!lua_isnil(L, 2)) { /* function? */
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lua_pushvalue(L, a-1); /* -1 to compensate function */
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lua_pushvalue(L, b-2); /* -2 to compensate function and `a' */
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res = lua_toboolean(L, -1);
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return lua_lessthan(L, a, b);
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static void auxsort (lua_State *L, int l, int u) {
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while (l < u) { /* for tail recursion */
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/* sort elements a[l], a[(l+u)/2] and a[u] */
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lua_rawgeti(L, 1, l);
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lua_rawgeti(L, 1, u);
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if (sort_comp(L, -1, -2)) /* a[u] < a[l]? */
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set2(L, l, u); /* swap a[l] - a[u] */
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if (u-l == 1) break; /* only 2 elements */
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lua_rawgeti(L, 1, i);
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lua_rawgeti(L, 1, l);
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if (sort_comp(L, -2, -1)) /* a[i]<a[l]? */
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lua_pop(L, 1); /* remove a[l] */
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lua_rawgeti(L, 1, u);
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if (sort_comp(L, -1, -2)) /* a[u]<a[i]? */
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if (u-l == 2) break; /* only 3 elements */
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lua_rawgeti(L, 1, i); /* Pivot */
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lua_pushvalue(L, -1);
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lua_rawgeti(L, 1, u-1);
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/* a[l] <= P == a[u-1] <= a[u], only need to sort from l+1 to u-2 */
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for (;;) { /* invariant: a[l..i] <= P <= a[j..u] */
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/* repeat ++i until a[i] >= P */
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while (lua_rawgeti(L, 1, ++i), sort_comp(L, -1, -2)) {
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if (i>u) luaL_error(L, "invalid order function for sorting");
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lua_pop(L, 1); /* remove a[i] */
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/* repeat --j until a[j] <= P */
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while (lua_rawgeti(L, 1, --j), sort_comp(L, -3, -1)) {
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if (j<l) luaL_error(L, "invalid order function for sorting");
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lua_pop(L, 1); /* remove a[j] */
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lua_pop(L, 3); /* pop pivot, a[i], a[j] */
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lua_rawgeti(L, 1, u-1);
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lua_rawgeti(L, 1, i);
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set2(L, u-1, i); /* swap pivot (a[u-1]) with a[i] */
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/* a[l..i-1] <= a[i] == P <= a[i+1..u] */
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/* adjust so that smaller half is in [j..i] and larger one in [l..u] */
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auxsort(L, j, i); /* call recursively the smaller one */
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} /* repeat the routine for the larger one */
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static int sort (lua_State *L) {
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int n = aux_getn(L, 1);
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luaL_checkstack(L, 40, ""); /* assume array is smaller than 2^40 */
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if (!lua_isnoneornil(L, 2)) /* is there a 2nd argument? */
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luaL_checktype(L, 2, LUA_TFUNCTION);
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lua_settop(L, 2); /* make sure there is two arguments */
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/* }====================================================== */
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static const luaL_Reg tab_funcs[] = {
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{"foreach", foreach},
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{"foreachi", foreachi},
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LUALIB_API int luaopen_table (lua_State *L) {
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luaL_register(L, LUA_TABLIBNAME, tab_funcs);