1 files changed, 450 insertions, 0 deletions

diff --git a/ltablib.c b/ltablib.c
new file mode 100644
index 0000000..98b2f87
--- /dev/null
+++ b/ltablib.c
@@ -0,0 +1,450 @@
+/*
+** $Id: ltablib.c,v 1.93 2016/02/25 19:41:54 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;
+}
+