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comparison lib/lua/lua-5.2.2/ltablib.c @ 1866:41cc4dd3c122

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Lua 5.2.2 added.
author Nomad
date Wed, 16 Oct 2013 13:34:26 +0200
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1848:3b39b70e8e93 1866:41cc4dd3c122
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