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rlm@1:   luaL_error(L, LUA_QL("setn") " is obsolete");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