1 /* 2 ** $Id: ltablib.c,v 1.65.1.2 2014/05/07 16:32:55 roberto Exp $ 3 ** Library for Table Manipulation 4 ** See Copyright Notice in lua.h 5 */ 6 7 8 #define ltablib_c 9 #define LUA_LIB 10 11 #include <sys/lua/lua.h> 12 13 #include <sys/lua/lauxlib.h> 14 #include <sys/lua/lualib.h> 15 16 17 #define aux_getn(L,n) (luaL_checktype(L, n, LUA_TTABLE), luaL_len(L, n)) 18 19 20 21 #if defined(LUA_COMPAT_MAXN) 22 static int maxn (lua_State *L) { 23 lua_Number max = 0; 24 luaL_checktype(L, 1, LUA_TTABLE); 25 lua_pushnil(L); /* first key */ 26 while (lua_next(L, 1)) { 27 lua_pop(L, 1); /* remove value */ 28 if (lua_type(L, -1) == LUA_TNUMBER) { 29 lua_Number v = lua_tonumber(L, -1); 30 if (v > max) max = v; 31 } 32 } 33 lua_pushnumber(L, max); 34 return 1; 35 } 36 #endif 37 38 39 static int tinsert (lua_State *L) { 40 int e = aux_getn(L, 1) + 1; /* first empty element */ 41 int pos; /* where to insert new element */ 42 switch (lua_gettop(L)) { 43 case 2: { /* called with only 2 arguments */ 44 pos = e; /* insert new element at the end */ 45 break; 46 } 47 case 3: { 48 int i; 49 pos = luaL_checkint(L, 2); /* 2nd argument is the position */ 50 luaL_argcheck(L, 1 <= pos && pos <= e, 2, "position out of bounds"); 51 for (i = e; i > pos; i--) { /* move up elements */ 52 lua_rawgeti(L, 1, i-1); 53 lua_rawseti(L, 1, i); /* t[i] = t[i-1] */ 54 } 55 break; 56 } 57 default: { 58 return luaL_error(L, "wrong number of arguments to " LUA_QL("insert")); 59 } 60 } 61 lua_rawseti(L, 1, pos); /* t[pos] = v */ 62 return 0; 63 } 64 65 66 static int tremove (lua_State *L) { 67 int size = aux_getn(L, 1); 68 int pos = luaL_optint(L, 2, size); 69 if (pos != size) /* validate 'pos' if given */ 70 luaL_argcheck(L, 1 <= pos && pos <= size + 1, 1, "position out of bounds"); 71 lua_rawgeti(L, 1, pos); /* result = t[pos] */ 72 for ( ; pos < size; pos++) { 73 lua_rawgeti(L, 1, pos+1); 74 lua_rawseti(L, 1, pos); /* t[pos] = t[pos+1] */ 75 } 76 lua_pushnil(L); 77 lua_rawseti(L, 1, pos); /* t[pos] = nil */ 78 return 1; 79 } 80 81 82 static void addfield (lua_State *L, luaL_Buffer *b, int i) { 83 lua_rawgeti(L, 1, i); 84 if (!lua_isstring(L, -1)) 85 luaL_error(L, "invalid value (%s) at index %d in table for " 86 LUA_QL("concat"), luaL_typename(L, -1), i); 87 luaL_addvalue(b); 88 } 89 90 91 static int tconcat (lua_State *L) { 92 luaL_Buffer b; 93 size_t lsep; 94 int i, last; 95 const char *sep = luaL_optlstring(L, 2, "", &lsep); 96 luaL_checktype(L, 1, LUA_TTABLE); 97 i = luaL_optint(L, 3, 1); 98 last = luaL_opt(L, luaL_checkint, 4, luaL_len(L, 1)); 99 luaL_buffinit(L, &b); 100 for (; i < last; i++) { 101 addfield(L, &b, i); 102 luaL_addlstring(&b, sep, lsep); 103 } 104 if (i == last) /* add last value (if interval was not empty) */ 105 addfield(L, &b, i); 106 luaL_pushresult(&b); 107 return 1; 108 } 109 110 111 /* 112 ** {====================================================== 113 ** Pack/unpack 114 ** ======================================================= 115 */ 116 117 static int pack (lua_State *L) { 118 int n = lua_gettop(L); /* number of elements to pack */ 119 lua_createtable(L, n, 1); /* create result table */ 120 lua_pushinteger(L, n); 121 lua_setfield(L, -2, "n"); /* t.n = number of elements */ 122 if (n > 0) { /* at least one element? */ 123 int i; 124 lua_pushvalue(L, 1); 125 lua_rawseti(L, -2, 1); /* insert first element */ 126 lua_replace(L, 1); /* move table into index 1 */ 127 for (i = n; i >= 2; i--) /* assign other elements */ 128 lua_rawseti(L, 1, i); 129 } 130 return 1; /* return table */ 131 } 132 133 134 static int unpack (lua_State *L) { 135 int i, e; 136 unsigned int n; 137 luaL_checktype(L, 1, LUA_TTABLE); 138 i = luaL_optint(L, 2, 1); 139 e = luaL_opt(L, luaL_checkint, 3, luaL_len(L, 1)); 140 if (i > e) return 0; /* empty range */ 141 n = (unsigned int)e - (unsigned int)i; /* number of elements minus 1 */ 142 if (n > (INT_MAX - 10) || !lua_checkstack(L, ++n)) 143 return luaL_error(L, "too many results to unpack"); 144 lua_rawgeti(L, 1, i); /* push arg[i] (avoiding overflow problems) */ 145 while (i++ < e) /* push arg[i + 1...e] */ 146 lua_rawgeti(L, 1, i); 147 return n; 148 } 149 150 /* }====================================================== */ 151 152 153 154 /* 155 ** {====================================================== 156 ** Quicksort 157 ** (based on `Algorithms in MODULA-3', Robert Sedgewick; 158 ** Addison-Wesley, 1993.) 159 ** ======================================================= 160 */ 161 162 163 static void set2 (lua_State *L, int i, int j) { 164 lua_rawseti(L, 1, i); 165 lua_rawseti(L, 1, j); 166 } 167 168 static int sort_comp (lua_State *L, int a, int b) { 169 if (!lua_isnil(L, 2)) { /* function? */ 170 int res; 171 lua_pushvalue(L, 2); 172 lua_pushvalue(L, a-1); /* -1 to compensate function */ 173 lua_pushvalue(L, b-2); /* -2 to compensate function and `a' */ 174 lua_call(L, 2, 1); 175 res = lua_toboolean(L, -1); 176 lua_pop(L, 1); 177 return res; 178 } 179 else /* a < b? */ 180 return lua_compare(L, a, b, LUA_OPLT); 181 } 182 183 static void auxsort (lua_State *L, int l, int u) { 184 while (l < u) { /* for tail recursion */ 185 int i, j; 186 /* sort elements a[l], a[(l+u)/2] and a[u] */ 187 lua_rawgeti(L, 1, l); 188 lua_rawgeti(L, 1, u); 189 if (sort_comp(L, -1, -2)) /* a[u] < a[l]? */ 190 set2(L, l, u); /* swap a[l] - a[u] */ 191 else 192 lua_pop(L, 2); 193 if (u-l == 1) break; /* only 2 elements */ 194 i = (l+u)/2; 195 lua_rawgeti(L, 1, i); 196 lua_rawgeti(L, 1, l); 197 if (sort_comp(L, -2, -1)) /* a[i]<a[l]? */ 198 set2(L, i, l); 199 else { 200 lua_pop(L, 1); /* remove a[l] */ 201 lua_rawgeti(L, 1, u); 202 if (sort_comp(L, -1, -2)) /* a[u]<a[i]? */ 203 set2(L, i, u); 204 else 205 lua_pop(L, 2); 206 } 207 if (u-l == 2) break; /* only 3 elements */ 208 lua_rawgeti(L, 1, i); /* Pivot */ 209 lua_pushvalue(L, -1); 210 lua_rawgeti(L, 1, u-1); 211 set2(L, i, u-1); 212 /* a[l] <= P == a[u-1] <= a[u], only need to sort from l+1 to u-2 */ 213 i = l; j = u-1; 214 for (;;) { /* invariant: a[l..i] <= P <= a[j..u] */ 215 /* repeat ++i until a[i] >= P */ 216 while (lua_rawgeti(L, 1, ++i), sort_comp(L, -1, -2)) { 217 if (i>=u) luaL_error(L, "invalid order function for sorting"); 218 lua_pop(L, 1); /* remove a[i] */ 219 } 220 /* repeat --j until a[j] <= P */ 221 while (lua_rawgeti(L, 1, --j), sort_comp(L, -3, -1)) { 222 if (j<=l) luaL_error(L, "invalid order function for sorting"); 223 lua_pop(L, 1); /* remove a[j] */ 224 } 225 if (j<i) { 226 lua_pop(L, 3); /* pop pivot, a[i], a[j] */ 227 break; 228 } 229 set2(L, i, j); 230 } 231 lua_rawgeti(L, 1, u-1); 232 lua_rawgeti(L, 1, i); 233 set2(L, u-1, i); /* swap pivot (a[u-1]) with a[i] */ 234 /* a[l..i-1] <= a[i] == P <= a[i+1..u] */ 235 /* adjust so that smaller half is in [j..i] and larger one in [l..u] */ 236 if (i-l < u-i) { 237 j=l; i=i-1; l=i+2; 238 } 239 else { 240 j=i+1; i=u; u=j-2; 241 } 242 auxsort(L, j, i); /* call recursively the smaller one */ 243 } /* repeat the routine for the larger one */ 244 } 245 246 static int tsort (lua_State *L) { 247 int n = aux_getn(L, 1); 248 luaL_checkstack(L, 40, ""); /* assume array is smaller than 2^40 */ 249 if (!lua_isnoneornil(L, 2)) /* is there a 2nd argument? */ 250 luaL_checktype(L, 2, LUA_TFUNCTION); 251 lua_settop(L, 2); /* make sure there is two arguments */ 252 auxsort(L, 1, n); 253 return 0; 254 } 255 256 /* }====================================================== */ 257 258 259 static const luaL_Reg tab_funcs[] = { 260 {"concat", tconcat}, 261 #if defined(LUA_COMPAT_MAXN) 262 {"maxn", maxn}, 263 #endif 264 {"insert", tinsert}, 265 {"pack", pack}, 266 {"unpack", unpack}, 267 {"remove", tremove}, 268 {"sort", tsort}, 269 {NULL, NULL} 270 }; 271 272 273 LUAMOD_API int luaopen_table (lua_State *L) { 274 luaL_newlib(L, tab_funcs); 275 #if defined(LUA_COMPAT_UNPACK) 276 /* _G.unpack = table.unpack */ 277 lua_getfield(L, -1, "unpack"); 278 lua_setglobal(L, "unpack"); 279 #endif 280 return 1; 281 } 282 283 #if defined(_KERNEL) 284 285 EXPORT_SYMBOL(luaopen_table); 286 287 #endif 288