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1, LUA_TTABLE); #ifndef luaL_setn luaL_setn(L, 1, luaL_checkint(L, 2)); #else luaL_error(L, LUA_QL("setn") " is obsolete"); #endif lua_pushvalue(L, 1); return 1; } static int tinsert (lua_State *L) { int e = aux_getn(L, 1) + 1; /* first empty element */ int pos; /* where to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