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| 1 /* |
| 2 ** $Id: ltablib.c,v 1.65 2013/03/07 18:17:24 roberto Exp $ |
| 3 ** Library for Table Manipulation |
| 4 ** See Copyright Notice in lua.h |
| 5 */ |
| 6 |
| 7 |
| 8 #include <stddef.h> |
| 9 |
| 10 #define ltablib_c |
| 11 #define LUA_LIB |
| 12 |
| 13 #include "lua.h" |
| 14 |
| 15 #include "lauxlib.h" |
| 16 #include "lualib.h" |
| 17 |
| 18 |
| 19 #define aux_getn(L,n) (luaL_checktype(L, n, LUA_TTABLE), luaL_len(L, n)) |
| 20 |
| 21 |
| 22 |
| 23 #if defined(LUA_COMPAT_MAXN) |
| 24 static int maxn (lua_State *L) { |
| 25 lua_Number max = 0; |
| 26 luaL_checktype(L, 1, LUA_TTABLE); |
| 27 lua_pushnil(L); /* first key */ |
| 28 while (lua_next(L, 1)) { |
| 29 lua_pop(L, 1); /* remove value */ |
| 30 if (lua_type(L, -1) == LUA_TNUMBER) { |
| 31 lua_Number v = lua_tonumber(L, -1); |
| 32 if (v > max) max = v; |
| 33 } |
| 34 } |
| 35 lua_pushnumber(L, max); |
| 36 return 1; |
| 37 } |
| 38 #endif |
| 39 |
| 40 |
| 41 static int tinsert (lua_State *L) { |
| 42 int e = aux_getn(L, 1) + 1; /* first empty element */ |
| 43 int pos; /* where to insert new element */ |
| 44 switch (lua_gettop(L)) { |
| 45 case 2: { /* called with only 2 arguments */ |
| 46 pos = e; /* insert new element at the end */ |
| 47 break; |
| 48 } |
| 49 case 3: { |
| 50 int i; |
| 51 pos = luaL_checkint(L, 2); /* 2nd argument is the position */ |
| 52 luaL_argcheck(L, 1 <= pos && pos <= e, 2, "position out of bounds"); |
| 53 for (i = e; i > pos; i--) { /* move up elements */ |
| 54 lua_rawgeti(L, 1, i-1); |
| 55 lua_rawseti(L, 1, i); /* t[i] = t[i-1] */ |
| 56 } |
| 57 break; |
| 58 } |
| 59 default: { |
| 60 return luaL_error(L, "wrong number of arguments to " LUA_QL("insert")); |
| 61 } |
| 62 } |
| 63 lua_rawseti(L, 1, pos); /* t[pos] = v */ |
| 64 return 0; |
| 65 } |
| 66 |
| 67 |
| 68 static int tremove (lua_State *L) { |
| 69 int size = aux_getn(L, 1); |
| 70 int pos = luaL_optint(L, 2, size); |
| 71 if (pos != size) /* validate 'pos' if given */ |
| 72 luaL_argcheck(L, 1 <= pos && pos <= size + 1, 1, "position out of bounds"); |
| 73 lua_rawgeti(L, 1, pos); /* result = t[pos] */ |
| 74 for ( ; pos < size; pos++) { |
| 75 lua_rawgeti(L, 1, pos+1); |
| 76 lua_rawseti(L, 1, pos); /* t[pos] = t[pos+1] */ |
| 77 } |
| 78 lua_pushnil(L); |
| 79 lua_rawseti(L, 1, pos); /* t[pos] = nil */ |
| 80 return 1; |
| 81 } |
| 82 |
| 83 |
| 84 static void addfield (lua_State *L, luaL_Buffer *b, int i) { |
| 85 lua_rawgeti(L, 1, i); |
| 86 if (!lua_isstring(L, -1)) |
| 87 luaL_error(L, "invalid value (%s) at index %d in table for " |
| 88 LUA_QL("concat"), luaL_typename(L, -1), i); |
| 89 luaL_addvalue(b); |
| 90 } |
| 91 |
| 92 |
| 93 static int tconcat (lua_State *L) { |
| 94 luaL_Buffer b; |
| 95 size_t lsep; |
| 96 int i, last; |
| 97 const char *sep = luaL_optlstring(L, 2, "", &lsep); |
| 98 luaL_checktype(L, 1, LUA_TTABLE); |
| 99 i = luaL_optint(L, 3, 1); |
| 100 last = luaL_opt(L, luaL_checkint, 4, luaL_len(L, 1)); |
| 101 luaL_buffinit(L, &b); |
| 102 for (; i < last; i++) { |
| 103 addfield(L, &b, i); |
| 104 luaL_addlstring(&b, sep, lsep); |
| 105 } |
| 106 if (i == last) /* add last value (if interval was not empty) */ |
| 107 addfield(L, &b, i); |
| 108 luaL_pushresult(&b); |
| 109 return 1; |
| 110 } |
| 111 |
| 112 |
| 113 /* |
| 114 ** {====================================================== |
| 115 ** Pack/unpack |
| 116 ** ======================================================= |
| 117 */ |
| 118 |
| 119 static int pack (lua_State *L) { |
| 120 int n = lua_gettop(L); /* number of elements to pack */ |
| 121 lua_createtable(L, n, 1); /* create result table */ |
| 122 lua_pushinteger(L, n); |
| 123 lua_setfield(L, -2, "n"); /* t.n = number of elements */ |
| 124 if (n > 0) { /* at least one element? */ |
| 125 int i; |
| 126 lua_pushvalue(L, 1); |
| 127 lua_rawseti(L, -2, 1); /* insert first element */ |
| 128 lua_replace(L, 1); /* move table into index 1 */ |
| 129 for (i = n; i >= 2; i--) /* assign other elements */ |
| 130 lua_rawseti(L, 1, i); |
| 131 } |
| 132 return 1; /* return table */ |
| 133 } |
| 134 |
| 135 |
| 136 static int unpack (lua_State *L) { |
| 137 int i, e, n; |
| 138 luaL_checktype(L, 1, LUA_TTABLE); |
| 139 i = luaL_optint(L, 2, 1); |
| 140 e = luaL_opt(L, luaL_checkint, 3, luaL_len(L, 1)); |
| 141 if (i > e) return 0; /* empty range */ |
| 142 n = e - i + 1; /* number of elements */ |
| 143 if (n <= 0 || !lua_checkstack(L, n)) /* n <= 0 means arith. overflow */ |
| 144 return luaL_error(L, "too many results to unpack"); |
| 145 lua_rawgeti(L, 1, i); /* push arg[i] (avoiding overflow problems) */ |
| 146 while (i++ < e) /* push arg[i + 1...e] */ |
| 147 lua_rawgeti(L, 1, i); |
| 148 return n; |
| 149 } |
| 150 |
| 151 /* }====================================================== */ |
| 152 |
| 153 |
| 154 |
| 155 /* |
| 156 ** {====================================================== |
| 157 ** Quicksort |
| 158 ** (based on `Algorithms in MODULA-3', Robert Sedgewick; |
| 159 ** Addison-Wesley, 1993.) |
| 160 ** ======================================================= |
| 161 */ |
| 162 |
| 163 |
| 164 static void set2 (lua_State *L, int i, int j) { |
| 165 lua_rawseti(L, 1, i); |
| 166 lua_rawseti(L, 1, j); |
| 167 } |
| 168 |
| 169 static int sort_comp (lua_State *L, int a, int b) { |
| 170 if (!lua_isnil(L, 2)) { /* function? */ |
| 171 int res; |
| 172 lua_pushvalue(L, 2); |
| 173 lua_pushvalue(L, a-1); /* -1 to compensate function */ |
| 174 lua_pushvalue(L, b-2); /* -2 to compensate function and `a' */ |
| 175 lua_call(L, 2, 1); |
| 176 res = lua_toboolean(L, -1); |
| 177 lua_pop(L, 1); |
| 178 return res; |
| 179 } |
| 180 else /* a < b? */ |
| 181 return lua_compare(L, a, b, LUA_OPLT); |
| 182 } |
| 183 |
| 184 static void auxsort (lua_State *L, int l, int u) { |
| 185 while (l < u) { /* for tail recursion */ |
| 186 int i, j; |
| 187 /* sort elements a[l], a[(l+u)/2] and a[u] */ |
| 188 lua_rawgeti(L, 1, l); |
| 189 lua_rawgeti(L, 1, u); |
| 190 if (sort_comp(L, -1, -2)) /* a[u] < a[l]? */ |
| 191 set2(L, l, u); /* swap a[l] - a[u] */ |
| 192 else |
| 193 lua_pop(L, 2); |
| 194 if (u-l == 1) break; /* only 2 elements */ |
| 195 i = (l+u)/2; |
| 196 lua_rawgeti(L, 1, i); |
| 197 lua_rawgeti(L, 1, l); |
| 198 if (sort_comp(L, -2, -1)) /* a[i]<a[l]? */ |
| 199 set2(L, i, l); |
| 200 else { |
| 201 lua_pop(L, 1); /* remove a[l] */ |
| 202 lua_rawgeti(L, 1, u); |
| 203 if (sort_comp(L, -1, -2)) /* a[u]<a[i]? */ |
| 204 set2(L, i, u); |
| 205 else |
| 206 lua_pop(L, 2); |
| 207 } |
| 208 if (u-l == 2) break; /* only 3 elements */ |
| 209 lua_rawgeti(L, 1, i); /* Pivot */ |
| 210 lua_pushvalue(L, -1); |
| 211 lua_rawgeti(L, 1, u-1); |
| 212 set2(L, i, u-1); |
| 213 /* a[l] <= P == a[u-1] <= a[u], only need to sort from l+1 to u-2 */ |
| 214 i = l; j = u-1; |
| 215 for (;;) { /* invariant: a[l..i] <= P <= a[j..u] */ |
| 216 /* repeat ++i until a[i] >= P */ |
| 217 while (lua_rawgeti(L, 1, ++i), sort_comp(L, -1, -2)) { |
| 218 if (i>=u) luaL_error(L, "invalid order function for sorting"); |
| 219 lua_pop(L, 1); /* remove a[i] */ |
| 220 } |
| 221 /* repeat --j until a[j] <= P */ |
| 222 while (lua_rawgeti(L, 1, --j), sort_comp(L, -3, -1)) { |
| 223 if (j<=l) luaL_error(L, "invalid order function for sorting"); |
| 224 lua_pop(L, 1); /* remove a[j] */ |
| 225 } |
| 226 if (j<i) { |
| 227 lua_pop(L, 3); /* pop pivot, a[i], a[j] */ |
| 228 break; |
| 229 } |
| 230 set2(L, i, j); |
| 231 } |
| 232 lua_rawgeti(L, 1, u-1); |
| 233 lua_rawgeti(L, 1, i); |
| 234 set2(L, u-1, i); /* swap pivot (a[u-1]) with a[i] */ |
| 235 /* a[l..i-1] <= a[i] == P <= a[i+1..u] */ |
| 236 /* adjust so that smaller half is in [j..i] and larger one in [l..u] */ |
| 237 if (i-l < u-i) { |
| 238 j=l; i=i-1; l=i+2; |
| 239 } |
| 240 else { |
| 241 j=i+1; i=u; u=j-2; |
| 242 } |
| 243 auxsort(L, j, i); /* call recursively the smaller one */ |
| 244 } /* repeat the routine for the larger one */ |
| 245 } |
| 246 |
| 247 static int sort (lua_State *L) { |
| 248 int n = aux_getn(L, 1); |
| 249 luaL_checkstack(L, 40, ""); /* assume array is smaller than 2^40 */ |
| 250 if (!lua_isnoneornil(L, 2)) /* is there a 2nd argument? */ |
| 251 luaL_checktype(L, 2, LUA_TFUNCTION); |
| 252 lua_settop(L, 2); /* make sure there is two arguments */ |
| 253 auxsort(L, 1, n); |
| 254 return 0; |
| 255 } |
| 256 |
| 257 /* }====================================================== */ |
| 258 |
| 259 |
| 260 static const luaL_Reg tab_funcs[] = { |
| 261 {"concat", tconcat}, |
| 262 #if defined(LUA_COMPAT_MAXN) |
| 263 {"maxn", maxn}, |
| 264 #endif |
| 265 {"insert", tinsert}, |
| 266 {"pack", pack}, |
| 267 {"unpack", unpack}, |
| 268 {"remove", tremove}, |
| 269 {"sort", sort}, |
| 270 {NULL, NULL} |
| 271 }; |
| 272 |
| 273 |
| 274 LUAMOD_API int luaopen_table (lua_State *L) { |
| 275 luaL_newlib(L, tab_funcs); |
| 276 #if defined(LUA_COMPAT_UNPACK) |
| 277 /* _G.unpack = table.unpack */ |
| 278 lua_getfield(L, -1, "unpack"); |
| 279 lua_setglobal(L, "unpack"); |
| 280 #endif |
| 281 return 1; |
| 282 } |
| 283 |
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