/*** $Id: ltablib.c,v 1.38 2005/10/23 17:38:15 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1, LUA_TTABLE);#ifndef luaL_setn  luaL_setn(L, 1, luaL_checkint(L, 2));#else  luaL_error(L, LUA_QL("setn") " is obsolete");#endif  lua_pushvalue(L, 1);  return 1;}static int tinsert (lua_State *L) {  int e = aux_getn(L, 1) + 1;  /* first empty element */  int pos;  /* where to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 (e == 0) return 0;  /* table is `empty' */  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 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++) {    lua_rawgeti(L, 1, i);    luaL_argcheck(L, lua_isstring(L, -1), 1, "table contains non-strings");    luaL_addvalue(&b);    if (i != last)      luaL_addlstring(&b, sep, lsep);  }  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;}