| /* |
| ** $Id: ltablib.c,v 1.79 2014/11/02 19:19:04 roberto Exp roberto $ |
| ** 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; |
| } |
| |