diff options
Diffstat (limited to 'src/ltablib.c')
-rw-r--r-- | src/ltablib.c | 287 |
1 files changed, 287 insertions, 0 deletions
diff --git a/src/ltablib.c b/src/ltablib.c new file mode 100644 index 0000000..b6d9cb4 --- /dev/null +++ b/src/ltablib.c @@ -0,0 +1,287 @@ +/* +** $Id: ltablib.c,v 1.38.1.3 2008/02/14 16:46:58 roberto Exp $ +** Library for Table Manipulation +** See Copyright Notice in lua.h +*/ + + +#include <stddef.h> + +#define ltablib_c +#define LUA_LIB + +#include "lua.h" + +#include "lauxlib.h" +#include "lualib.h" + + +#define aux_getn(L,n) (luaL_checktype(L, n, LUA_TTABLE), luaL_getn(L, n)) + + +static int foreachi (lua_State *L) { + int i; + int n = aux_getn(L, 1); + luaL_checktype(L, 2, LUA_TFUNCTION); + for (i=1; i <= n; i++) { + lua_pushvalue(L, 2); /* function */ + lua_pushinteger(L, i); /* 1st argument */ + lua_rawgeti(L, 1, i); /* 2nd argument */ + lua_call(L, 2, 1); + if (!lua_isnil(L, -1)) + return 1; + lua_pop(L, 1); /* remove nil result */ + } + return 0; +} + + +static int foreach (lua_State *L) { + luaL_checktype(L, 1, LUA_TTABLE); + luaL_checktype(L, 2, LUA_TFUNCTION); + lua_pushnil(L); /* first key */ + while (lua_next(L, 1)) { + lua_pushvalue(L, 2); /* function */ + lua_pushvalue(L, -3); /* key */ + lua_pushvalue(L, -3); /* value */ + lua_call(L, 2, 1); + if (!lua_isnil(L, -1)) + return 1; + lua_pop(L, 2); /* remove value and result */ + } + return 0; +} + + +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; +} + + +static int getn (lua_State *L) { + lua_pushinteger(L, aux_getn(L, 1)); + return 1; +} + + +static int setn (lua_State *L) { + luaL_checktype(L, 1, LUA_TTABLE); +#ifndef luaL_setn + luaL_setn(L, 1, luaL_checkint(L, 2)); +#else + luaL_error(L, LUA_QL("setn") " is obsolete"); +#endif + lua_pushvalue(L, 1); + return 1; +} + + +static int tinsert (lua_State *L) { + int e = aux_getn(L, 1) + 1; /* first empty element */ + int pos; /*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: { + int i; + pos = luaL_checkint(L, 2); /* 2nd argument is the position */ + if (pos > e) e = pos; /* `grow' array if necessary */ + for (i = e; i > pos; i--) { /* move up elements */ + lua_rawgeti(L, 1, i-1); + lua_rawseti(L, 1, i); /* t[i] = t[i-1] */ + } + break; + } + default: { + return luaL_error(L, "wrong number of arguments to " LUA_QL("insert")); + } + } + luaL_setn(L, 1, e); /* new size */ + lua_rawseti(L, 1, pos); /* t[pos] = v */ + return 0; +} + + +static int tremove (lua_State *L) { + int e = aux_getn(L, 1); + int pos = luaL_optint(L, 2, e); + if (!(1 <= pos && pos <= e)) /* position is outside bounds? */ + return 0; /* nothing to remove */ + luaL_setn(L, 1, e - 1); /* t.n = n-1 */ + lua_rawgeti(L, 1, pos); /* result = t[pos] */ + for ( ;pos<e; pos++) { + lua_rawgeti(L, 1, pos+1); + lua_rawseti(L, 1, pos); /* t[pos] = t[pos+1] */ + } + lua_pushnil(L); + lua_rawseti(L, 1, e); /* t[e] = nil */ + return 1; +} + + +static void addfield (lua_State *L, luaL_Buffer *b, int i) { + lua_rawgeti(L, 1, i); + if (!lua_isstring(L, -1)) + luaL_error(L, "invalid value (%s) at index %d in table for " + LUA_QL("concat"), luaL_typename(L, -1), i); + luaL_addvalue(b); +} + + +static int tconcat (lua_State *L) { + luaL_Buffer b; + size_t lsep; + int i, last; + const char *sep = luaL_optlstring(L, 2, "", &lsep); + luaL_checktype(L, 1, LUA_TTABLE); + i = luaL_optint(L, 3, 1); + last = luaL_opt(L, luaL_checkint, 4, luaL_getn(L, 1)); + 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; +} + + + +/* +** {====================================================== +** Quicksort +** (based on `Algorithms in MODULA-3', Robert Sedgewick; +** Addison-Wesley, 1993.) +*/ + + +static void set2 (lua_State *L, int i, int j) { + lua_rawseti(L, 1, i); + lua_rawseti(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_lessthan(L, a, b); +} + +static void auxsort (lua_State *L, int l, int u) { + while (l < u) { /* for tail recursion */ + int i, j; + /* sort elements a[l], a[(l+u)/2] and a[u] */ + lua_rawgeti(L, 1, l); + lua_rawgeti(L, 1, u); + if (sort_comp(L, -1, -2)) /* a[u] < a[l]? */ + set2(L, l, u); /* swap a[l] - a[u] */ + else + lua_pop(L, 2); + if (u-l == 1) break; /* only 2 elements */ + i = (l+u)/2; + lua_rawgeti(L, 1, i); + lua_rawgeti(L, 1, l); + if (sort_comp(L, -2, -1)) /* a[i]<a[l]? */ + set2(L, i, l); + else { + lua_pop(L, 1); /* remove a[l] */ + lua_rawgeti(L, 1, u); + if (sort_comp(L, -1, -2)) /* a[u]<a[i]? */ + set2(L, i, u); + else + lua_pop(L, 2); + } + if (u-l == 2) break; /* only 3 elements */ + lua_rawgeti(L, 1, i); /* Pivot */ + lua_pushvalue(L, -1); + lua_rawgeti(L, 1, u-1); + set2(L, 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 (lua_rawgeti(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 (lua_rawgeti(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, i, j); + } + lua_rawgeti(L, 1, u-1); + lua_rawgeti(L, 1, i); + set2(L, 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, j, i); /* call recursively the smaller one */ + } /* repeat the routine for the larger one */ +} + +static int sort (lua_State *L) { + int n = aux_getn(L, 1); + luaL_checkstack(L, 40, ""); /* assume array is smaller than 2^40 */ + if (!lua_isnoneornil(L, 2)) /* is there a 2nd argument? */ + luaL_checktype(L, 2, LUA_TFUNCTION); + lua_settop(L, 2); /* make sure there is two arguments */ + auxsort(L, 1, n); + return 0; +} + +/* }====================================================== */ + + +static const luaL_Reg tab_funcs[] = { + {"concat", tconcat}, + {"foreach", foreach}, + {"foreachi", foreachi}, + {"getn", getn}, + {"maxn", maxn}, + {"insert", tinsert}, + {"remove", tremove}, + {"setn", setn}, + {"sort", sort}, + {NULL, NULL} +}; + + +LUALIB_API int luaopen_table (lua_State *L) { + luaL_register(L, LUA_TABLIBNAME, tab_funcs); + return 1; +} + |