osb/source/extern/lua/ltablib.c
2023-06-20 14:33:09 +10:00

360 lines
9.7 KiB
C

/*
** $Id: ltablib.c,v 1.80 2015/01/13 16:27:29 roberto Exp $
** Library for Table Manipulation
** See Copyright Notice in lua.h
*/
#define ltablib_c
#define LUA_LIB
#include "lprefix.h"
#include <limits.h>
#include <stddef.h>
#include "lua.h"
#include "lauxlib.h"
#include "lualib.h"
/*
** Structure with table-access functions
*/
typedef struct {
int (*geti) (lua_State *L, int idx, lua_Integer n);
void (*seti) (lua_State *L, int idx, lua_Integer n);
} TabA;
/*
** Check that 'arg' has a table and set access functions in 'ta' to raw
** or non-raw according to the presence of corresponding metamethods.
*/
static void checktab (lua_State *L, int arg, TabA *ta) {
ta->geti = NULL; ta->seti = NULL;
if (lua_getmetatable(L, arg)) {
lua_pushliteral(L, "__index"); /* 'index' metamethod */
if (lua_rawget(L, -2) != LUA_TNIL)
ta->geti = lua_geti;
lua_pushliteral(L, "__newindex"); /* 'newindex' metamethod */
if (lua_rawget(L, -3) != LUA_TNIL)
ta->seti = lua_seti;
lua_pop(L, 3); /* pop metatable plus both metamethods */
}
if (ta->geti == NULL || ta->seti == NULL) {
luaL_checktype(L, arg, LUA_TTABLE); /* must be table for raw methods */
if (ta->geti == NULL) ta->geti = lua_rawgeti;
if (ta->seti == NULL) ta->seti = lua_rawseti;
}
}
#define aux_getn(L,n,ta) (checktab(L, n, ta), luaL_len(L, n))
#if defined(LUA_COMPAT_MAXN)
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;
}
#endif
static int tinsert (lua_State *L) {
TabA ta;
lua_Integer e = aux_getn(L, 1, &ta) + 1; /* first empty element */
lua_Integer 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: {
lua_Integer i;
pos = luaL_checkinteger(L, 2); /* 2nd argument is the position */
luaL_argcheck(L, 1 <= pos && pos <= e, 2, "position out of bounds");
for (i = e; i > pos; i--) { /* move up elements */
(*ta.geti)(L, 1, i - 1);
(*ta.seti)(L, 1, i); /* t[i] = t[i - 1] */
}
break;
}
default: {
return luaL_error(L, "wrong number of arguments to 'insert'");
}
}
(*ta.seti)(L, 1, pos); /* t[pos] = v */
return 0;
}
static int tremove (lua_State *L) {
TabA ta;
lua_Integer size = aux_getn(L, 1, &ta);
lua_Integer pos = luaL_optinteger(L, 2, size);
if (pos != size) /* validate 'pos' if given */
luaL_argcheck(L, 1 <= pos && pos <= size + 1, 1, "position out of bounds");
(*ta.geti)(L, 1, pos); /* result = t[pos] */
for ( ; pos < size; pos++) {
(*ta.geti)(L, 1, pos + 1);
(*ta.seti)(L, 1, pos); /* t[pos] = t[pos + 1] */
}
lua_pushnil(L);
(*ta.seti)(L, 1, pos); /* t[pos] = nil */
return 1;
}
static int tmove (lua_State *L) {
TabA ta;
lua_Integer f = luaL_checkinteger(L, 2);
lua_Integer e = luaL_checkinteger(L, 3);
lua_Integer t = luaL_checkinteger(L, 4);
int tt = !lua_isnoneornil(L, 5) ? 5 : 1; /* destination table */
if (e >= f) { /* otherwise, nothing to move */
lua_Integer n, i;
ta.geti = (luaL_getmetafield(L, 1, "__index") == LUA_TNIL)
? (luaL_checktype(L, 1, LUA_TTABLE), lua_rawgeti)
: lua_geti;
ta.seti = (luaL_getmetafield(L, tt, "__newindex") == LUA_TNIL)
? (luaL_checktype(L, tt, LUA_TTABLE), lua_rawseti)
: lua_seti;
luaL_argcheck(L, f > 0 || e < LUA_MAXINTEGER + f, 3,
"too many elements to move");
n = e - f + 1; /* number of elements to move */
luaL_argcheck(L, t <= LUA_MAXINTEGER - n + 1, 4,
"destination wrap around");
if (t > f) {
for (i = n - 1; i >= 0; i--) {
(*ta.geti)(L, 1, f + i);
(*ta.seti)(L, tt, t + i);
}
}
else {
for (i = 0; i < n; i++) {
(*ta.geti)(L, 1, f + i);
(*ta.seti)(L, tt, t + i);
}
}
}
lua_pushvalue(L, tt); /* return "to table" */
return 1;
}
static void addfield (lua_State *L, luaL_Buffer *b, TabA *ta, lua_Integer i) {
(*ta->geti)(L, 1, i);
if (!lua_isstring(L, -1))
luaL_error(L, "invalid value (%s) at index %d in table for 'concat'",
luaL_typename(L, -1), i);
luaL_addvalue(b);
}
static int tconcat (lua_State *L) {
TabA ta;
luaL_Buffer b;
size_t lsep;
lua_Integer i, last;
const char *sep = luaL_optlstring(L, 2, "", &lsep);
checktab(L, 1, &ta);
i = luaL_optinteger(L, 3, 1);
last = luaL_opt(L, luaL_checkinteger, 4, luaL_len(L, 1));
luaL_buffinit(L, &b);
for (; i < last; i++) {
addfield(L, &b, &ta, i);
luaL_addlstring(&b, sep, lsep);
}
if (i == last) /* add last value (if interval was not empty) */
addfield(L, &b, &ta, i);
luaL_pushresult(&b);
return 1;
}
/*
** {======================================================
** Pack/unpack
** =======================================================
*/
static int pack (lua_State *L) {
int i;
int n = lua_gettop(L); /* number of elements to pack */
lua_createtable(L, n, 1); /* create result table */
lua_insert(L, 1); /* put it at index 1 */
for (i = n; i >= 1; i--) /* assign elements */
lua_rawseti(L, 1, i);
lua_pushinteger(L, n);
lua_setfield(L, 1, "n"); /* t.n = number of elements */
return 1; /* return table */
}
static int unpack (lua_State *L) {
TabA ta;
lua_Integer i, e;
lua_Unsigned n;
checktab(L, 1, &ta);
i = luaL_optinteger(L, 2, 1);
e = luaL_opt(L, luaL_checkinteger, 3, luaL_len(L, 1));
if (i > e) return 0; /* empty range */
n = (lua_Unsigned)e - i; /* number of elements minus 1 (avoid overflows) */
if (n >= (unsigned int)INT_MAX || !lua_checkstack(L, (int)(++n)))
return luaL_error(L, "too many results to unpack");
do { /* must have at least one element */
(*ta.geti)(L, 1, i); /* push arg[i..e] */
} while (i++ < e);
return (int)n;
}
/* }====================================================== */
/*
** {======================================================
** Quicksort
** (based on 'Algorithms in MODULA-3', Robert Sedgewick;
** Addison-Wesley, 1993.)
** =======================================================
*/
static void set2 (lua_State *L, TabA *ta, int i, int j) {
(*ta->seti)(L, 1, i);
(*ta->seti)(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_compare(L, a, b, LUA_OPLT);
}
static void auxsort (lua_State *L, TabA *ta, int l, int u) {
while (l < u) { /* for tail recursion */
int i, j;
/* sort elements a[l], a[(l+u)/2] and a[u] */
(*ta->geti)(L, 1, l);
(*ta->geti)(L, 1, u);
if (sort_comp(L, -1, -2)) /* a[u] < a[l]? */
set2(L, ta, l, u); /* swap a[l] - a[u] */
else
lua_pop(L, 2);
if (u-l == 1) break; /* only 2 elements */
i = (l+u)/2;
(*ta->geti)(L, 1, i);
(*ta->geti)(L, 1, l);
if (sort_comp(L, -2, -1)) /* a[i]<a[l]? */
set2(L, ta, i, l);
else {
lua_pop(L, 1); /* remove a[l] */
(*ta->geti)(L, 1, u);
if (sort_comp(L, -1, -2)) /* a[u]<a[i]? */
set2(L, ta, i, u);
else
lua_pop(L, 2);
}
if (u-l == 2) break; /* only 3 elements */
(*ta->geti)(L, 1, i); /* Pivot */
lua_pushvalue(L, -1);
(*ta->geti)(L, 1, u-1);
set2(L, ta, 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 ((*ta->geti)(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 ((*ta->geti)(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, ta, i, j);
}
(*ta->geti)(L, 1, u-1);
(*ta->geti)(L, 1, i);
set2(L, ta, 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, ta, j, i); /* call recursively the smaller one */
} /* repeat the routine for the larger one */
}
static int sort (lua_State *L) {
TabA ta;
int n = (int)aux_getn(L, 1, &ta);
luaL_checkstack(L, 50, ""); /* assume array is smaller than 2^50 */
if (!lua_isnoneornil(L, 2)) /* is there a 2nd argument? */
luaL_checktype(L, 2, LUA_TFUNCTION);
lua_settop(L, 2); /* make sure there are two arguments */
auxsort(L, &ta, 1, n);
return 0;
}
/* }====================================================== */
static const luaL_Reg tab_funcs[] = {
{"concat", tconcat},
#if defined(LUA_COMPAT_MAXN)
{"maxn", maxn},
#endif
{"insert", tinsert},
{"pack", pack},
{"unpack", unpack},
{"remove", tremove},
{"move", tmove},
{"sort", sort},
{NULL, NULL}
};
LUAMOD_API int luaopen_table (lua_State *L) {
luaL_newlib(L, tab_funcs);
#if defined(LUA_COMPAT_UNPACK)
/* _G.unpack = table.unpack */
lua_getfield(L, -1, "unpack");
lua_setglobal(L, "unpack");
#endif
return 1;
}