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21d3294c | 1 | /* |
2 | ** $Id: ltablib.c,v 1.38.1.3 2008/02/14 16:46:58 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_getn(L, n)) | |
20 | ||
21 | ||
22 | static int foreachi (lua_State *L) { | |
23 | int i; | |
24 | int n = aux_getn(L, 1); | |
25 | luaL_checktype(L, 2, LUA_TFUNCTION); | |
26 | for (i=1; i <= n; i++) { | |
27 | lua_pushvalue(L, 2); /* function */ | |
28 | lua_pushinteger(L, i); /* 1st argument */ | |
29 | lua_rawgeti(L, 1, i); /* 2nd argument */ | |
30 | lua_call(L, 2, 1); | |
31 | if (!lua_isnil(L, -1)) | |
32 | return 1; | |
33 | lua_pop(L, 1); /* remove nil result */ | |
34 | } | |
35 | return 0; | |
36 | } | |
37 | ||
38 | ||
39 | static int foreach (lua_State *L) { | |
40 | luaL_checktype(L, 1, LUA_TTABLE); | |
41 | luaL_checktype(L, 2, LUA_TFUNCTION); | |
42 | lua_pushnil(L); /* first key */ | |
43 | while (lua_next(L, 1)) { | |
44 | lua_pushvalue(L, 2); /* function */ | |
45 | lua_pushvalue(L, -3); /* key */ | |
46 | lua_pushvalue(L, -3); /* value */ | |
47 | lua_call(L, 2, 1); | |
48 | if (!lua_isnil(L, -1)) | |
49 | return 1; | |
50 | lua_pop(L, 2); /* remove value and result */ | |
51 | } | |
52 | return 0; | |
53 | } | |
54 | ||
55 | ||
56 | static int maxn (lua_State *L) { | |
57 | lua_Number max = 0; | |
58 | luaL_checktype(L, 1, LUA_TTABLE); | |
59 | lua_pushnil(L); /* first key */ | |
60 | while (lua_next(L, 1)) { | |
61 | lua_pop(L, 1); /* remove value */ | |
62 | if (lua_type(L, -1) == LUA_TNUMBER) { | |
63 | lua_Number v = lua_tonumber(L, -1); | |
64 | if (v > max) max = v; | |
65 | } | |
66 | } | |
67 | lua_pushnumber(L, max); | |
68 | return 1; | |
69 | } | |
70 | ||
71 | ||
72 | static int getn (lua_State *L) { | |
73 | lua_pushinteger(L, aux_getn(L, 1)); | |
74 | return 1; | |
75 | } | |
76 | ||
77 | ||
78 | static int setn (lua_State *L) { | |
79 | luaL_checktype(L, 1, LUA_TTABLE); | |
80 | #ifndef luaL_setn | |
81 | luaL_setn(L, 1, luaL_checkint(L, 2)); | |
82 | #else | |
83 | luaL_error(L, LUA_QL("setn") " is obsolete"); | |
84 | #endif | |
85 | lua_pushvalue(L, 1); | |
86 | return 1; | |
87 | } | |
88 | ||
89 | ||
90 | static int tinsert (lua_State *L) { | |
91 | int e = aux_getn(L, 1) + 1; /* first empty element */ | |
92 | int pos; /* where to insert new element */ | |
93 | switch (lua_gettop(L)) { | |
94 | case 2: { /* called with only 2 arguments */ | |
95 | pos = e; /* insert new element at the end */ | |
96 | break; | |
97 | } | |
98 | case 3: { | |
99 | int i; | |
100 | pos = luaL_checkint(L, 2); /* 2nd argument is the position */ | |
101 | if (pos > e) e = pos; /* `grow' array if necessary */ | |
102 | for (i = e; i > pos; i--) { /* move up elements */ | |
103 | lua_rawgeti(L, 1, i-1); | |
104 | lua_rawseti(L, 1, i); /* t[i] = t[i-1] */ | |
105 | } | |
106 | break; | |
107 | } | |
108 | default: { | |
109 | return luaL_error(L, "wrong number of arguments to " LUA_QL("insert")); | |
110 | } | |
111 | } | |
112 | luaL_setn(L, 1, e); /* new size */ | |
113 | lua_rawseti(L, 1, pos); /* t[pos] = v */ | |
114 | return 0; | |
115 | } | |
116 | ||
117 | ||
118 | static int tremove (lua_State *L) { | |
119 | int e = aux_getn(L, 1); | |
120 | int pos = luaL_optint(L, 2, e); | |
121 | if (!(1 <= pos && pos <= e)) /* position is outside bounds? */ | |
122 | return 0; /* nothing to remove */ | |
123 | luaL_setn(L, 1, e - 1); /* t.n = n-1 */ | |
124 | lua_rawgeti(L, 1, pos); /* result = t[pos] */ | |
125 | for ( ;pos<e; pos++) { | |
126 | lua_rawgeti(L, 1, pos+1); | |
127 | lua_rawseti(L, 1, pos); /* t[pos] = t[pos+1] */ | |
128 | } | |
129 | lua_pushnil(L); | |
130 | lua_rawseti(L, 1, e); /* t[e] = nil */ | |
131 | return 1; | |
132 | } | |
133 | ||
134 | ||
135 | static void addfield (lua_State *L, luaL_Buffer *b, int i) { | |
136 | lua_rawgeti(L, 1, i); | |
137 | if (!lua_isstring(L, -1)) | |
138 | luaL_error(L, "invalid value (%s) at index %d in table for " | |
139 | LUA_QL("concat"), luaL_typename(L, -1), i); | |
140 | luaL_addvalue(b); | |
141 | } | |
142 | ||
143 | ||
144 | static int tconcat (lua_State *L) { | |
145 | luaL_Buffer b; | |
146 | size_t lsep; | |
147 | int i, last; | |
148 | const char *sep = luaL_optlstring(L, 2, "", &lsep); | |
149 | luaL_checktype(L, 1, LUA_TTABLE); | |
150 | i = luaL_optint(L, 3, 1); | |
151 | last = luaL_opt(L, luaL_checkint, 4, luaL_getn(L, 1)); | |
152 | luaL_buffinit(L, &b); | |
153 | for (; i < last; i++) { | |
154 | addfield(L, &b, i); | |
155 | luaL_addlstring(&b, sep, lsep); | |
156 | } | |
157 | if (i == last) /* add last value (if interval was not empty) */ | |
158 | addfield(L, &b, i); | |
159 | luaL_pushresult(&b); | |
160 | return 1; | |
161 | } | |
162 | ||
163 | ||
164 | ||
165 | /* | |
166 | ** {====================================================== | |
167 | ** Quicksort | |
168 | ** (based on `Algorithms in MODULA-3', Robert Sedgewick; | |
169 | ** Addison-Wesley, 1993.) | |
170 | */ | |
171 | ||
172 | ||
173 | static void set2 (lua_State *L, int i, int j) { | |
174 | lua_rawseti(L, 1, i); | |
175 | lua_rawseti(L, 1, j); | |
176 | } | |
177 | ||
178 | static int sort_comp (lua_State *L, int a, int b) { | |
179 | if (!lua_isnil(L, 2)) { /* function? */ | |
180 | int res; | |
181 | lua_pushvalue(L, 2); | |
182 | lua_pushvalue(L, a-1); /* -1 to compensate function */ | |
183 | lua_pushvalue(L, b-2); /* -2 to compensate function and `a' */ | |
184 | lua_call(L, 2, 1); | |
185 | res = lua_toboolean(L, -1); | |
186 | lua_pop(L, 1); | |
187 | return res; | |
188 | } | |
189 | else /* a < b? */ | |
190 | return lua_lessthan(L, a, b); | |
191 | } | |
192 | ||
193 | static void auxsort (lua_State *L, int l, int u) { | |
194 | while (l < u) { /* for tail recursion */ | |
195 | int i, j; | |
196 | /* sort elements a[l], a[(l+u)/2] and a[u] */ | |
197 | lua_rawgeti(L, 1, l); | |
198 | lua_rawgeti(L, 1, u); | |
199 | if (sort_comp(L, -1, -2)) /* a[u] < a[l]? */ | |
200 | set2(L, l, u); /* swap a[l] - a[u] */ | |
201 | else | |
202 | lua_pop(L, 2); | |
203 | if (u-l == 1) break; /* only 2 elements */ | |
204 | i = (l+u)/2; | |
205 | lua_rawgeti(L, 1, i); | |
206 | lua_rawgeti(L, 1, l); | |
207 | if (sort_comp(L, -2, -1)) /* a[i]<a[l]? */ | |
208 | set2(L, i, l); | |
209 | else { | |
210 | lua_pop(L, 1); /* remove a[l] */ | |
211 | lua_rawgeti(L, 1, u); | |
212 | if (sort_comp(L, -1, -2)) /* a[u]<a[i]? */ | |
213 | set2(L, i, u); | |
214 | else | |
215 | lua_pop(L, 2); | |
216 | } | |
217 | if (u-l == 2) break; /* only 3 elements */ | |
218 | lua_rawgeti(L, 1, i); /* Pivot */ | |
219 | lua_pushvalue(L, -1); | |
220 | lua_rawgeti(L, 1, u-1); | |
221 | set2(L, i, u-1); | |
222 | /* a[l] <= P == a[u-1] <= a[u], only need to sort from l+1 to u-2 */ | |
223 | i = l; j = u-1; | |
224 | for (;;) { /* invariant: a[l..i] <= P <= a[j..u] */ | |
225 | /* repeat ++i until a[i] >= P */ | |
226 | while (lua_rawgeti(L, 1, ++i), sort_comp(L, -1, -2)) { | |
227 | if (i>u) luaL_error(L, "invalid order function for sorting"); | |
228 | lua_pop(L, 1); /* remove a[i] */ | |
229 | } | |
230 | /* repeat --j until a[j] <= P */ | |
231 | while (lua_rawgeti(L, 1, --j), sort_comp(L, -3, -1)) { | |
232 | if (j<l) luaL_error(L, "invalid order function for sorting"); | |
233 | lua_pop(L, 1); /* remove a[j] */ | |
234 | } | |
235 | if (j<i) { | |
236 | lua_pop(L, 3); /* pop pivot, a[i], a[j] */ | |
237 | break; | |
238 | } | |
239 | set2(L, i, j); | |
240 | } | |
241 | lua_rawgeti(L, 1, u-1); | |
242 | lua_rawgeti(L, 1, i); | |
243 | set2(L, u-1, i); /* swap pivot (a[u-1]) with a[i] */ | |
244 | /* a[l..i-1] <= a[i] == P <= a[i+1..u] */ | |
245 | /* adjust so that smaller half is in [j..i] and larger one in [l..u] */ | |
246 | if (i-l < u-i) { | |
247 | j=l; i=i-1; l=i+2; | |
248 | } | |
249 | else { | |
250 | j=i+1; i=u; u=j-2; | |
251 | } | |
252 | auxsort(L, j, i); /* call recursively the smaller one */ | |
253 | } /* repeat the routine for the larger one */ | |
254 | } | |
255 | ||
256 | static int sort (lua_State *L) { | |
257 | int n = aux_getn(L, 1); | |
258 | luaL_checkstack(L, 40, ""); /* assume array is smaller than 2^40 */ | |
259 | if (!lua_isnoneornil(L, 2)) /* is there a 2nd argument? */ | |
260 | luaL_checktype(L, 2, LUA_TFUNCTION); | |
261 | lua_settop(L, 2); /* make sure there is two arguments */ | |
262 | auxsort(L, 1, n); | |
263 | return 0; | |
264 | } | |
265 | ||
266 | /* }====================================================== */ | |
267 | ||
268 | ||
269 | static const luaL_Reg tab_funcs[] = { | |
270 | {"concat", tconcat}, | |
271 | {"foreach", foreach}, | |
272 | {"foreachi", foreachi}, | |
273 | {"getn", getn}, | |
274 | {"maxn", maxn}, | |
275 | {"insert", tinsert}, | |
276 | {"remove", tremove}, | |
277 | {"setn", setn}, | |
278 | {"sort", sort}, | |
279 | {NULL, NULL} | |
280 | }; | |
281 | ||
282 | ||
283 | LUALIB_API int luaopen_table (lua_State *L) { | |
284 | luaL_register(L, LUA_TABLIBNAME, tab_funcs); | |
285 | return 1; | |
286 | } | |
287 |