commit 76a73cb2eef71eac3c93e9263443131164ee9fb9
parent aa3da1605ceb50fe8353ecb7d03b6f074e131284
Author: Roberto Ierusalimschy <roberto@inf.puc-rio.br>
Date: Mon, 1 Jul 2002 16:25:06 -0300
new `getn' (and `setn')
Diffstat:
| M | ltablib.c | | | 127 | ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++------------------- |
1 file changed, 97 insertions(+), 30 deletions(-)
diff --git a/ltablib.c b/ltablib.c
@@ -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;
}
