ltablib.c
(5.0.3)
/*
** $Id: ltablib.c,v 1.21 2003/04/03 13:35:34 roberto Exp $
** Library for Table Manipulation
** See Copyright Notice in lua.h
*/
#include <stddef.h>
#define ltablib_c
#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 luaB_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_pushnumber(L, (lua_Number)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 luaB_foreach (lua_State *L) {
luaL_checktype(L, 1, LUA_TTABLE);
luaL_checktype(L, 2, LUA_TFUNCTION);
lua_pushnil(L); /* first key */
for (;;) {
if (lua_next(L, 1) == 0)
return 0;
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 */
}
}
static int luaB_getn (lua_State *L) {
lua_pushnumber(L, (lua_Number)aux_getn(L, 1));
return 1;
}
static int luaB_setn (lua_State *L) {
luaL_checktype(L, 1, LUA_TTABLE);
luaL_setn(L, 1, luaL_checkint(L, 2));
return 0;
}
static int luaB_tinsert (lua_State *L) {
int v = lua_gettop(L); /* number of arguments */
int n = aux_getn(L, 1) + 1;
int pos; /* where to insert new element */
if (v == 2) /* called with only 2 arguments */
pos = n; /* insert new element at the end */
else {
pos = luaL_checkint(L, 2); /* 2nd argument is the position */
if (pos > n) n = pos; /* `grow' array if necessary */
v = 3; /* function may be called with more than 3 args */
}
luaL_setn(L, 1, n); /* new size */
while (--n >= pos) { /* move up elements */
lua_rawgeti(L, 1, n);
lua_rawseti(L, 1, n+1); /* t[n+1] = t[n] */
}
lua_pushvalue(L, v);
lua_rawseti(L, 1, pos); /* t[pos] = v */
return 0;
}
static int luaB_tremove (lua_State *L) {
int n = aux_getn(L, 1);
int pos = luaL_optint(L, 2, n);
if (n <= 0) return 0; /* table is `empty' */
luaL_setn(L, 1, n-1); /* t.n = n-1 */
lua_rawgeti(L, 1, pos); /* result = t[pos] */
for ( ;pos<n; pos++) {
lua_rawgeti(L, 1, pos+1);
lua_rawseti(L, 1, pos); /* t[pos] = t[pos+1] */
}
lua_pushnil(L);
lua_rawseti(L, 1, n); /* t[n] = nil */
return 1;
}
static int str_concat (lua_State *L) {
luaL_Buffer b;
size_t lsep;
const char *sep = luaL_optlstring(L, 2, "", &lsep);
int i = luaL_optint(L, 3, 1);
int n = luaL_optint(L, 4, 0);
luaL_checktype(L, 1, LUA_TTABLE);
if (n == 0) n = luaL_getn(L, 1);
luaL_buffinit(L, &b);
for (; i <= n; i++) {
lua_rawgeti(L, 1, i);
luaL_argcheck(L, lua_isstring(L, -1), 1, "table contains non-strings");
luaL_addvalue(&b);
if (i != n)
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 luaB_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", str_concat},
{"foreach", luaB_foreach},
{"foreachi", luaB_foreachi},
{"getn", luaB_getn},
{"setn", luaB_setn},
{"sort", luaB_sort},
{"insert", luaB_tinsert},
{"remove", luaB_tremove},
{NULL, NULL}
};
LUALIB_API int luaopen_table (lua_State *L) {
luaL_openlib(L, LUA_TABLIBNAME, tab_funcs, 0);
return 1;
}