new `getn' (and `setn')

This commit is contained in:
Roberto Ierusalimschy 2002-07-01 16:25:28 -03:00
parent aa3da1605c
commit 76a73cb2ee
1 changed files with 97 additions and 30 deletions

127
ltablib.c
View File

@ -1,5 +1,5 @@
/*
** $Id: ltablib.c,v 1.7 2002/06/18 15:16:18 roberto Exp roberto $
** $Id: ltablib.c,v 1.8 2002/06/25 19:16:44 roberto Exp roberto $
** Library for Table Manipulation
** See Copyright Notice in lua.h
*/
@ -15,12 +15,57 @@
static int checkint (lua_State *L) {
int n = lua_tonumber(L, -1);
if (n == 0 && !lua_isnumber(L, -1)) n = -1;
lua_pop(L, 1);
return n;
}
static void aux_setn (lua_State *L, int t, int n) {
lua_pushliteral(L, "n");
lua_rawget(L, t);
if (checkint(L) >= 0) {
lua_pushliteral(L, "n"); /* use it */
lua_pushnumber(L, n);
lua_rawset(L, t);
}
else { /* use N */
lua_pushvalue(L, t);
lua_pushnumber(L, n);
lua_rawset(L, lua_upvalueindex(1)); /* N[t] = n */
}
}
static int aux_getn (lua_State *L, int t) {
int n;
luaL_check_type(L, t, LUA_TTABLE);
lua_pushliteral(L, "n"); /* try t.n */
lua_rawget(L, t);
if ((n = checkint(L)) >= 0) return n;
lua_pushvalue(L, t); /* try N[t] */
lua_rawget(L, lua_upvalueindex(1));
if ((n = checkint(L)) >= 0) return n;
else { /* must count elements */
n = 0;
for (;;) {
lua_rawgeti(L, t, ++n);
if (lua_isnil(L, -1)) break;
lua_pop(L, 1);
}
lua_pop(L, 1);
aux_setn(L, t, n - 1);
return n - 1;
}
}
static int luaB_foreachi (lua_State *L) {
int n, i;
luaL_check_type(L, 1, LUA_TTABLE);
int i;
int n = aux_getn(L, 1);
luaL_check_type(L, 2, LUA_TFUNCTION);
n = lua_getn(L, 1);
for (i=1; i<=n; i++) {
lua_pushvalue(L, 2); /* function */
lua_pushnumber(L, i); /* 1st argument */
@ -52,34 +97,32 @@ static int luaB_foreach (lua_State *L) {
}
static void aux_setn (lua_State *L, int t, int n) {
lua_pushliteral(L, "n");
lua_pushnumber(L, n);
lua_rawset(L, t);
static int luaB_getn (lua_State *L) {
lua_pushnumber(L, aux_getn(L, 1));
return 1;
}
static int luaB_getn (lua_State *L) {
static int luaB_setn (lua_State *L) {
luaL_check_type(L, 1, LUA_TTABLE);
lua_pushnumber(L, lua_getn(L, 1));
return 1;
aux_setn(L, 1, luaL_check_int(L, 2));
return 0;
}
static int luaB_tinsert (lua_State *L) {
int v = lua_gettop(L); /* number of arguments */
int n, pos;
luaL_check_type(L, 1, LUA_TTABLE);
n = lua_getn(L, 1);
int n = aux_getn(L, 1) + 1;
int pos; /* where to insert new element */
if (v == 2) /* called with only 2 arguments */
pos = n+1;
pos = n; /* insert new element at the end */
else {
v = 3; /* function may be called with more than 3 args */
pos = luaL_check_int(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 */
}
if (pos > n+1) n = pos-1;
aux_setn(L, 1, n+1); /* t.n = n+1 */
for (; n>=pos; n--) {
aux_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] */
}
@ -90,16 +133,14 @@ static int luaB_tinsert (lua_State *L) {
static int luaB_tremove (lua_State *L) {
int pos, n;
luaL_check_type(L, 1, LUA_TTABLE);
n = lua_getn(L, 1);
pos = luaL_opt_int(L, 2, n);
int n = aux_getn(L, 1);
int pos = luaL_opt_int(L, 2, n);
if (n <= 0) return 0; /* table is `empty' */
aux_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); /* a[pos] = a[pos+1] */
lua_rawseti(L, 1, pos); /* t[pos] = t[pos+1] */
}
lua_pushnil(L);
lua_rawseti(L, 1, n); /* t[n] = nil */
@ -107,6 +148,26 @@ static int luaB_tremove (lua_State *L) {
}
static int str_concat (lua_State *L) {
luaL_Buffer b;
int n = aux_getn(L, 1);
size_t lsep;
const char *sep = luaL_opt_lstr(L, 2, "", &lsep);
int i;
luaL_buffinit(L, &b);
for (i=1; i<=n; i++) {
lua_rawgeti(L, 1, i);
luaL_arg_check(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;
}
/*
** {======================================================
@ -122,8 +183,7 @@ static void set2 (lua_State *L, int i, int j) {
}
static int sort_comp (lua_State *L, int a, int b) {
/* WARNING: the caller (auxsort) must ensure stack space */
if (!lua_isnoneornil(L, 2)) { /* function? */
if (!lua_isnil(L, 2)) { /* function? */
int res;
lua_pushvalue(L, 2);
lua_pushvalue(L, a-1); /* -1 to compensate function */
@ -201,9 +261,8 @@ static void auxsort (lua_State *L, int l, int u) {
}
static int luaB_sort (lua_State *L) {
int n;
luaL_check_type(L, 1, LUA_TTABLE);
n = lua_getn(L, 1);
int n = aux_getn(L, 1);
luaL_check_stack(L, 40, ""); /* assume array is smaller than 2^40 */
if (!lua_isnoneornil(L, 2)) /* is there a 2nd argument? */
luaL_check_type(L, 2, LUA_TFUNCTION);
lua_settop(L, 2); /* make sure there is two arguments */
@ -215,9 +274,11 @@ static int luaB_sort (lua_State *L) {
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},
@ -226,7 +287,13 @@ static const luaL_reg tab_funcs[] = {
LUALIB_API int lua_tablibopen (lua_State *L) {
luaL_opennamedlib(L, LUA_TABLIBNAME, tab_funcs, 0);
lua_newtable(L); /* create N (table to store num. elements in tables) */
lua_pushvalue(L, -1);
lua_setmetatable(L, -2); /* make it its own metatable */
lua_pushliteral(L, "__mode");
lua_pushliteral(L, "k");
lua_rawset(L, -3); /* make it a weak table */
luaL_opennamedlib(L, LUA_TABLIBNAME, tab_funcs, 1);
return 0;
}