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-rw-r--r--lua-5.3.5/ltablib.c450
1 files changed, 450 insertions, 0 deletions
diff --git a/lua-5.3.5/ltablib.c b/lua-5.3.5/ltablib.c
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+++ b/lua-5.3.5/ltablib.c
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+/*
+** $Id: ltablib.c,v 1.93.1.1 2017/04/19 17:20:42 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 <string.h>
+
+#include "lua.h"
+
+#include "lauxlib.h"
+#include "lualib.h"
+
+
+/*
+** Operations that an object must define to mimic a table
+** (some functions only need some of them)
+*/
+#define TAB_R 1 /* read */
+#define TAB_W 2 /* write */
+#define TAB_L 4 /* length */
+#define TAB_RW (TAB_R | TAB_W) /* read/write */
+
+
+#define aux_getn(L,n,w) (checktab(L, n, (w) | TAB_L), luaL_len(L, n))
+
+
+static int checkfield (lua_State *L, const char *key, int n) {
+ lua_pushstring(L, key);
+ return (lua_rawget(L, -n) != LUA_TNIL);
+}
+
+
+/*
+** Check that 'arg' either is a table or can behave like one (that is,
+** has a metatable with the required metamethods)
+*/
+static void checktab (lua_State *L, int arg, int what) {
+ if (lua_type(L, arg) != LUA_TTABLE) { /* is it not a table? */
+ int n = 1; /* number of elements to pop */
+ if (lua_getmetatable(L, arg) && /* must have metatable */
+ (!(what & TAB_R) || checkfield(L, "__index", ++n)) &&
+ (!(what & TAB_W) || checkfield(L, "__newindex", ++n)) &&
+ (!(what & TAB_L) || checkfield(L, "__len", ++n))) {
+ lua_pop(L, n); /* pop metatable and tested metamethods */
+ }
+ else
+ luaL_checktype(L, arg, LUA_TTABLE); /* force an error */
+ }
+}
+
+
+#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) {
+ lua_Integer e = aux_getn(L, 1, TAB_RW) + 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 */
+ lua_geti(L, 1, i - 1);
+ lua_seti(L, 1, i); /* t[i] = t[i - 1] */
+ }
+ break;
+ }
+ default: {
+ return luaL_error(L, "wrong number of arguments to 'insert'");
+ }
+ }
+ lua_seti(L, 1, pos); /* t[pos] = v */
+ return 0;
+}
+
+
+static int tremove (lua_State *L) {
+ lua_Integer size = aux_getn(L, 1, TAB_RW);
+ 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");
+ lua_geti(L, 1, pos); /* result = t[pos] */
+ for ( ; pos < size; pos++) {
+ lua_geti(L, 1, pos + 1);
+ lua_seti(L, 1, pos); /* t[pos] = t[pos + 1] */
+ }
+ lua_pushnil(L);
+ lua_seti(L, 1, pos); /* t[pos] = nil */
+ return 1;
+}
+
+
+/*
+** Copy elements (1[f], ..., 1[e]) into (tt[t], tt[t+1], ...). Whenever
+** possible, copy in increasing order, which is better for rehashing.
+** "possible" means destination after original range, or smaller
+** than origin, or copying to another table.
+*/
+static int tmove (lua_State *L) {
+ 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 */
+ checktab(L, 1, TAB_R);
+ checktab(L, tt, TAB_W);
+ if (e >= f) { /* otherwise, nothing to move */
+ lua_Integer n, i;
+ 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 > e || t <= f || (tt != 1 && !lua_compare(L, 1, tt, LUA_OPEQ))) {
+ for (i = 0; i < n; i++) {
+ lua_geti(L, 1, f + i);
+ lua_seti(L, tt, t + i);
+ }
+ }
+ else {
+ for (i = n - 1; i >= 0; i--) {
+ lua_geti(L, 1, f + i);
+ lua_seti(L, tt, t + i);
+ }
+ }
+ }
+ lua_pushvalue(L, tt); /* return destination table */
+ return 1;
+}
+
+
+static void addfield (lua_State *L, luaL_Buffer *b, lua_Integer i) {
+ lua_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) {
+ luaL_Buffer b;
+ lua_Integer last = aux_getn(L, 1, TAB_R);
+ size_t lsep;
+ const char *sep = luaL_optlstring(L, 2, "", &lsep);
+ lua_Integer i = luaL_optinteger(L, 3, 1);
+ last = luaL_optinteger(L, 4, last);
+ luaL_buffinit(L, &b);
+ for (; i < last; i++) {
+ addfield(L, &b, i);
+ luaL_addlstring(&b, sep, lsep);
+ }
+ if (i == last) /* add last value (if interval was not empty) */
+ addfield(L, &b, 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_seti(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) {
+ lua_Unsigned n;
+ lua_Integer i = luaL_optinteger(L, 2, 1);
+ lua_Integer 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");
+ for (; i < e; i++) { /* push arg[i..e - 1] (to avoid overflows) */
+ lua_geti(L, 1, i);
+ }
+ lua_geti(L, 1, e); /* push last element */
+ return (int)n;
+}
+
+/* }====================================================== */
+
+
+
+/*
+** {======================================================
+** Quicksort
+** (based on 'Algorithms in MODULA-3', Robert Sedgewick;
+** Addison-Wesley, 1993.)
+** =======================================================
+*/
+
+
+/* type for array indices */
+typedef unsigned int IdxT;
+
+
+/*
+** Produce a "random" 'unsigned int' to randomize pivot choice. This
+** macro is used only when 'sort' detects a big imbalance in the result
+** of a partition. (If you don't want/need this "randomness", ~0 is a
+** good choice.)
+*/
+#if !defined(l_randomizePivot) /* { */
+
+#include <time.h>
+
+/* size of 'e' measured in number of 'unsigned int's */
+#define sof(e) (sizeof(e) / sizeof(unsigned int))
+
+/*
+** Use 'time' and 'clock' as sources of "randomness". Because we don't
+** know the types 'clock_t' and 'time_t', we cannot cast them to
+** anything without risking overflows. A safe way to use their values
+** is to copy them to an array of a known type and use the array values.
+*/
+static unsigned int l_randomizePivot (void) {
+ clock_t c = clock();
+ time_t t = time(NULL);
+ unsigned int buff[sof(c) + sof(t)];
+ unsigned int i, rnd = 0;
+ memcpy(buff, &c, sof(c) * sizeof(unsigned int));
+ memcpy(buff + sof(c), &t, sof(t) * sizeof(unsigned int));
+ for (i = 0; i < sof(buff); i++)
+ rnd += buff[i];
+ return rnd;
+}
+
+#endif /* } */
+
+
+/* arrays larger than 'RANLIMIT' may use randomized pivots */
+#define RANLIMIT 100u
+
+
+static void set2 (lua_State *L, IdxT i, IdxT j) {
+ lua_seti(L, 1, i);
+ lua_seti(L, 1, j);
+}
+
+
+/*
+** Return true iff value at stack index 'a' is less than the value at
+** index 'b' (according to the order of the sort).
+*/
+static int sort_comp (lua_State *L, int a, int b) {
+ if (lua_isnil(L, 2)) /* no function? */
+ return lua_compare(L, a, b, LUA_OPLT); /* a < b */
+ else { /* function */
+ int res;
+ lua_pushvalue(L, 2); /* push function */
+ 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); /* call function */
+ res = lua_toboolean(L, -1); /* get result */
+ lua_pop(L, 1); /* pop result */
+ return res;
+ }
+}
+
+
+/*
+** Does the partition: Pivot P is at the top of the stack.
+** precondition: a[lo] <= P == a[up-1] <= a[up],
+** so it only needs to do the partition from lo + 1 to up - 2.
+** Pos-condition: a[lo .. i - 1] <= a[i] == P <= a[i + 1 .. up]
+** returns 'i'.
+*/
+static IdxT partition (lua_State *L, IdxT lo, IdxT up) {
+ IdxT i = lo; /* will be incremented before first use */
+ IdxT j = up - 1; /* will be decremented before first use */
+ /* loop invariant: a[lo .. i] <= P <= a[j .. up] */
+ for (;;) {
+ /* next loop: repeat ++i while a[i] < P */
+ while (lua_geti(L, 1, ++i), sort_comp(L, -1, -2)) {
+ if (i == up - 1) /* a[i] < P but a[up - 1] == P ?? */
+ luaL_error(L, "invalid order function for sorting");
+ lua_pop(L, 1); /* remove a[i] */
+ }
+ /* after the loop, a[i] >= P and a[lo .. i - 1] < P */
+ /* next loop: repeat --j while P < a[j] */
+ while (lua_geti(L, 1, --j), sort_comp(L, -3, -1)) {
+ if (j < i) /* j < i but a[j] > P ?? */
+ luaL_error(L, "invalid order function for sorting");
+ lua_pop(L, 1); /* remove a[j] */
+ }
+ /* after the loop, a[j] <= P and a[j + 1 .. up] >= P */
+ if (j < i) { /* no elements out of place? */
+ /* a[lo .. i - 1] <= P <= a[j + 1 .. i .. up] */
+ lua_pop(L, 1); /* pop a[j] */
+ /* swap pivot (a[up - 1]) with a[i] to satisfy pos-condition */
+ set2(L, up - 1, i);
+ return i;
+ }
+ /* otherwise, swap a[i] - a[j] to restore invariant and repeat */
+ set2(L, i, j);
+ }
+}
+
+
+/*
+** Choose an element in the middle (2nd-3th quarters) of [lo,up]
+** "randomized" by 'rnd'
+*/
+static IdxT choosePivot (IdxT lo, IdxT up, unsigned int rnd) {
+ IdxT r4 = (up - lo) / 4; /* range/4 */
+ IdxT p = rnd % (r4 * 2) + (lo + r4);
+ lua_assert(lo + r4 <= p && p <= up - r4);
+ return p;
+}
+
+
+/*
+** QuickSort algorithm (recursive function)
+*/
+static void auxsort (lua_State *L, IdxT lo, IdxT up,
+ unsigned int rnd) {
+ while (lo < up) { /* loop for tail recursion */
+ IdxT p; /* Pivot index */
+ IdxT n; /* to be used later */
+ /* sort elements 'lo', 'p', and 'up' */
+ lua_geti(L, 1, lo);
+ lua_geti(L, 1, up);
+ if (sort_comp(L, -1, -2)) /* a[up] < a[lo]? */
+ set2(L, lo, up); /* swap a[lo] - a[up] */
+ else
+ lua_pop(L, 2); /* remove both values */
+ if (up - lo == 1) /* only 2 elements? */
+ return; /* already sorted */
+ if (up - lo < RANLIMIT || rnd == 0) /* small interval or no randomize? */
+ p = (lo + up)/2; /* middle element is a good pivot */
+ else /* for larger intervals, it is worth a random pivot */
+ p = choosePivot(lo, up, rnd);
+ lua_geti(L, 1, p);
+ lua_geti(L, 1, lo);
+ if (sort_comp(L, -2, -1)) /* a[p] < a[lo]? */
+ set2(L, p, lo); /* swap a[p] - a[lo] */
+ else {
+ lua_pop(L, 1); /* remove a[lo] */
+ lua_geti(L, 1, up);
+ if (sort_comp(L, -1, -2)) /* a[up] < a[p]? */
+ set2(L, p, up); /* swap a[up] - a[p] */
+ else
+ lua_pop(L, 2);
+ }
+ if (up - lo == 2) /* only 3 elements? */
+ return; /* already sorted */
+ lua_geti(L, 1, p); /* get middle element (Pivot) */
+ lua_pushvalue(L, -1); /* push Pivot */
+ lua_geti(L, 1, up - 1); /* push a[up - 1] */
+ set2(L, p, up - 1); /* swap Pivot (a[p]) with a[up - 1] */
+ p = partition(L, lo, up);
+ /* a[lo .. p - 1] <= a[p] == P <= a[p + 1 .. up] */
+ if (p - lo < up - p) { /* lower interval is smaller? */
+ auxsort(L, lo, p - 1, rnd); /* call recursively for lower interval */
+ n = p - lo; /* size of smaller interval */
+ lo = p + 1; /* tail call for [p + 1 .. up] (upper interval) */
+ }
+ else {
+ auxsort(L, p + 1, up, rnd); /* call recursively for upper interval */
+ n = up - p; /* size of smaller interval */
+ up = p - 1; /* tail call for [lo .. p - 1] (lower interval) */
+ }
+ if ((up - lo) / 128 > n) /* partition too imbalanced? */
+ rnd = l_randomizePivot(); /* try a new randomization */
+ } /* tail call auxsort(L, lo, up, rnd) */
+}
+
+
+static int sort (lua_State *L) {
+ lua_Integer n = aux_getn(L, 1, TAB_RW);
+ if (n > 1) { /* non-trivial interval? */
+ luaL_argcheck(L, n < INT_MAX, 1, "array too big");
+ if (!lua_isnoneornil(L, 2)) /* is there a 2nd argument? */
+ luaL_checktype(L, 2, LUA_TFUNCTION); /* must be a function */
+ lua_settop(L, 2); /* make sure there are two arguments */
+ auxsort(L, 1, (IdxT)n, 0);
+ }
+ 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;
+}
+