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small optimization in "sort" + new functions "getn" and "foreachi"

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This commit is contained in:
Roberto Ierusalimschy 1998-11-13 14:39:18 -02:00
parent a84bca67fc
commit 8e3bd752bb
1 changed files with 63 additions and 33 deletions
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96
lbuiltin.c
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@ -1,5 +1,5 @@
/*
** $Id: lbuiltin.c,v 1.33 1998/07/12 16:16:43 roberto Exp roberto $
** $Id: lbuiltin.c,v 1.34 1998/08/21 17:43:44 roberto Exp roberto $
** Built-in functions
** See Copyright Notice in lua.h
*/
@ -36,6 +36,35 @@ static void pushstring (TaggedString *s)
}
static int getsize (TObject *t) {
int max = 0;
int i;
Hash *h = avalue(t);
LUA_ASSERT(ttype(t) == LUA_T_ARRAY, "table expected");
for (i = 0; i<nhash(h); i++) {
Node *n = h->node+i;
if (ttype(ref(n)) == LUA_T_NUMBER && ttype(val(n)) != LUA_T_NIL &&
(int)nvalue(ref(n)) > max)
max = nvalue(ref(n));
}
return max;
}
static int getnarg (lua_Object table) {
lua_Object temp;
/* temp = table.n */
lua_pushobject(table); lua_pushstring("n"); temp = lua_rawgettable();
return (lua_isnumber(temp) ? lua_getnumber(temp) :
getsize(luaA_Address(table)));
}
static void getn (void) {
lua_pushnumber(getnarg(luaL_tablearg(1)));
}
static void nextvar (void) {
TObject *o = luaA_Address(luaL_nonnullarg(1));
TaggedString *g;
@ -113,6 +142,26 @@ static void foreach (void) {
}
static void foreachi (void) {
lua_Object ot = luaL_tablearg(1);
Hash *t = avalue(luaA_Address(ot));
TObject f = *luaA_Address(luaL_functionarg(2));
int i;
int n = getnarg(ot);
luaD_checkstack(3); /* for f, ref, and val */
for (i=1; i<=n; i++) {
*(L->stack.top++) = f;
ttype(L->stack.top) = LUA_T_NUMBER;
nvalue(L->stack.top++) = i;
*(L->stack.top++) = *luaH_getint(t, i);
luaD_calln(2, 1);
if (ttype(L->stack.top-1) != LUA_T_NIL)
return;
L->stack.top--;
}
}
static void internaldostring (void)
{
long l;
@ -281,29 +330,6 @@ static void luatag (void)
}
static int getsize (TObject *t) {
int max = 0;
int i;
Hash *h = avalue(t);
LUA_ASSERT(ttype(t) == LUA_T_ARRAY, "table expected");
for (i = 0; i<nhash(h); i++) {
Node *n = h->node+i;
if (ttype(ref(n)) == LUA_T_NUMBER && ttype(val(n)) != LUA_T_NIL &&
(int)nvalue(ref(n)) > max)
max = nvalue(ref(n));
}
return max;
}
static int getnarg (lua_Object table) {
lua_Object temp;
/* temp = table.n */
lua_pushobject(table); lua_pushstring("n"); temp = lua_rawgettable();
return (lua_isnumber(temp) ? lua_getnumber(temp) :
getsize(luaA_Address(table)));
}
static void luaI_call (void) {
lua_Object f = luaL_nonnullarg(1);
lua_Object arg = luaL_tablearg(2);
@ -440,6 +466,7 @@ static int sort_comp (TObject *f, TObject *a, TObject *b) {
** quicksort algorithm from "Programming Pearls", pg. 112
*/
static void auxsort (Hash *a, int l, int u, TObject *f) {
init:
if (u <= l) return; /* 0 or 1 element */
luaD_checkstack(4); /* for pivot, f, a, b (sort_comp) */
if (u-l == 1) { /* only two elements? */
@ -461,8 +488,14 @@ static void auxsort (Hash *a, int l, int u, TObject *f) {
L->stack.top--; /* remove pivot from stack */
swap(a, l, m);
/* a[l..m-1] < a[m] <= a[m+1..u] */
auxsort(a, l, m-1, f);
auxsort(a, m+1, u, f);
if (m-l < u-m) { /* check which "half" is bigger */
auxsort(a, l, m-1, f); /* call recursively the smaller one */
l = m+1; goto init; /* auxsort(a, m+1, u, f); */
}
else {
auxsort(a, m+1, u, f);
u = m-1; goto init; /* auxsort(a, l, m-1, f); */
}
}
}
@ -471,13 +504,8 @@ static void luaB_sort (void) {
int n = getnarg(t);
Hash *a = avalue(luaA_Address(t));
lua_Object func = lua_getparam(2);
TObject *f;
if (func == LUA_NOOBJECT)
f = NULL;
else {
luaL_arg_check(lua_isfunction(func), 2, "function expected");
f = luaA_Address(func);
}
TObject *f = luaA_Address(func);
luaL_arg_check(!f || lua_isfunction(func), 2, "function expected");
auxsort(a, 1, n, f);
lua_pushobject(t);
}
@ -583,7 +611,9 @@ static struct luaL_reg int_funcs[] = {
{"error", luaI_error},
{"_ERRORMESSAGE", error_message},
{"foreach", foreach},
{"foreachi", foreachi},
{"foreachvar", foreachvar},
{"getn", getn},
{"getglobal", getglobal},
{"newtag", newtag},
{"next", next},