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authorPhilipp Janda <siffiejoe@gmx.net>2015-01-20 01:15:00 +0100
committerPhilipp Janda <siffiejoe@gmx.net>2015-01-20 01:15:00 +0100
commite52c3c4e7af665acd23e63fd3ae85f2c8ae87e49 (patch)
tree3067b1a8578cdddd9bdb1f5b5a3dba13c51a80fc /ltablib.c
parent489cd678823e0981ff2e4d2544b84094ed23c587 (diff)
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use table library from Lua 5.3 sources if available
Diffstat (limited to 'ltablib.c')
-rw-r--r--ltablib.c357
1 files changed, 357 insertions, 0 deletions
diff --git a/ltablib.c b/ltablib.c
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1/*
2** $Id: ltablib.c,v 1.79 2014/11/02 19:19:04 roberto Exp $
3** Library for Table Manipulation
4** See Copyright Notice in lua.h
5*/
6
7#define ltablib_c
8#define LUA_LIB
9
10#include "lprefix.h"
11
12
13#include <limits.h>
14#include <stddef.h>
15
16#include "lua.h"
17
18#include "lauxlib.h"
19#include "lualib.h"
20
21
22
23/*
24** Structure with table-access functions
25*/
26typedef struct {
27 int (*geti) (lua_State *L, int idx, lua_Integer n);
28 void (*seti) (lua_State *L, int idx, lua_Integer n);
29} TabA;
30
31
32/*
33** Check that 'arg' has a table and set access functions in 'ta' to raw
34** or non-raw according to the presence of corresponding metamethods.
35*/
36static void checktab (lua_State *L, int arg, TabA *ta) {
37 ta->geti = NULL; ta->seti = NULL;
38 if (lua_getmetatable(L, arg)) {
39 lua_pushliteral(L, "__index"); /* 'index' metamethod */
40 if (lua_rawget(L, -2) != LUA_TNIL)
41 ta->geti = lua_geti;
42 lua_pushliteral(L, "__newindex"); /* 'newindex' metamethod */
43 if (lua_rawget(L, -3) != LUA_TNIL)
44 ta->seti = lua_seti;
45 lua_pop(L, 3); /* pop metatable plus both metamethods */
46 }
47 if (ta->geti == NULL || ta->seti == NULL) {
48 luaL_checktype(L, arg, LUA_TTABLE); /* must be table for raw methods */
49 if (ta->geti == NULL) ta->geti = lua_rawgeti;
50 if (ta->seti == NULL) ta->seti = lua_rawseti;
51 }
52}
53
54
55#define aux_getn(L,n,ta) (checktab(L, n, ta), luaL_len(L, n))
56
57
58#if defined(LUA_COMPAT_MAXN)
59static int maxn (lua_State *L) {
60 lua_Number max = 0;
61 luaL_checktype(L, 1, LUA_TTABLE);
62 lua_pushnil(L); /* first key */
63 while (lua_next(L, 1)) {
64 lua_pop(L, 1); /* remove value */
65 if (lua_type(L, -1) == LUA_TNUMBER) {
66 lua_Number v = lua_tonumber(L, -1);
67 if (v > max) max = v;
68 }
69 }
70 lua_pushnumber(L, max);
71 return 1;
72}
73#endif
74
75
76static int tinsert (lua_State *L) {
77 TabA ta;
78 lua_Integer e = aux_getn(L, 1, &ta) + 1; /* first empty element */
79 lua_Integer pos; /* where to insert new element */
80 switch (lua_gettop(L)) {
81 case 2: { /* called with only 2 arguments */
82 pos = e; /* insert new element at the end */
83 break;
84 }
85 case 3: {
86 lua_Integer i;
87 pos = luaL_checkinteger(L, 2); /* 2nd argument is the position */
88 luaL_argcheck(L, 1 <= pos && pos <= e, 2, "position out of bounds");
89 for (i = e; i > pos; i--) { /* move up elements */
90 (*ta.geti)(L, 1, i - 1);
91 (*ta.seti)(L, 1, i); /* t[i] = t[i - 1] */
92 }
93 break;
94 }
95 default: {
96 return luaL_error(L, "wrong number of arguments to 'insert'");
97 }
98 }
99 (*ta.seti)(L, 1, pos); /* t[pos] = v */
100 return 0;
101}
102
103
104static int tremove (lua_State *L) {
105 TabA ta;
106 lua_Integer size = aux_getn(L, 1, &ta);
107 lua_Integer pos = luaL_optinteger(L, 2, size);
108 if (pos != size) /* validate 'pos' if given */
109 luaL_argcheck(L, 1 <= pos && pos <= size + 1, 1, "position out of bounds");
110 (*ta.geti)(L, 1, pos); /* result = t[pos] */
111 for ( ; pos < size; pos++) {
112 (*ta.geti)(L, 1, pos + 1);
113 (*ta.seti)(L, 1, pos); /* t[pos] = t[pos + 1] */
114 }
115 lua_pushnil(L);
116 (*ta.seti)(L, 1, pos); /* t[pos] = nil */
117 return 1;
118}
119
120
121static int tmove (lua_State *L) {
122 TabA ta;
123 lua_Integer f = luaL_checkinteger(L, 2);
124 lua_Integer e = luaL_checkinteger(L, 3);
125 lua_Integer t = luaL_checkinteger(L, 4);
126 int tt = !lua_isnoneornil(L, 5) ? 5 : 1; /* destination table */
127 /* the following restriction avoids several problems with overflows */
128 luaL_argcheck(L, f > 0, 2, "initial position must be positive");
129 if (e >= f) { /* otherwise, nothing to move */
130 lua_Integer n, i;
131 ta.geti = (luaL_getmetafield(L, 1, "__index") == LUA_TNIL)
132 ? (luaL_checktype(L, 1, LUA_TTABLE), lua_rawgeti)
133 : lua_geti;
134 ta.seti = (luaL_getmetafield(L, tt, "__newindex") == LUA_TNIL)
135 ? (luaL_checktype(L, tt, LUA_TTABLE), lua_rawseti)
136 : lua_seti;
137 n = e - f + 1; /* number of elements to move */
138 if (t > f) {
139 for (i = n - 1; i >= 0; i--) {
140 (*ta.geti)(L, 1, f + i);
141 (*ta.seti)(L, tt, t + i);
142 }
143 }
144 else {
145 for (i = 0; i < n; i++) {
146 (*ta.geti)(L, 1, f + i);
147 (*ta.seti)(L, tt, t + i);
148 }
149 }
150 }
151 lua_pushvalue(L, tt); /* return "to table" */
152 return 1;
153}
154
155
156static void addfield (lua_State *L, luaL_Buffer *b, TabA *ta, lua_Integer i) {
157 (*ta->geti)(L, 1, i);
158 if (!lua_isstring(L, -1))
159 luaL_error(L, "invalid value (%s) at index %d in table for 'concat'",
160 luaL_typename(L, -1), i);
161 luaL_addvalue(b);
162}
163
164
165static int tconcat (lua_State *L) {
166 TabA ta;
167 luaL_Buffer b;
168 size_t lsep;
169 lua_Integer i, last;
170 const char *sep = luaL_optlstring(L, 2, "", &lsep);
171 checktab(L, 1, &ta);
172 i = luaL_optinteger(L, 3, 1);
173 last = luaL_opt(L, luaL_checkinteger, 4, luaL_len(L, 1));
174 luaL_buffinit(L, &b);
175 for (; i < last; i++) {
176 addfield(L, &b, &ta, i);
177 luaL_addlstring(&b, sep, lsep);
178 }
179 if (i == last) /* add last value (if interval was not empty) */
180 addfield(L, &b, &ta, i);
181 luaL_pushresult(&b);
182 return 1;
183}
184
185
186/*
187** {======================================================
188** Pack/unpack
189** =======================================================
190*/
191
192static int pack (lua_State *L) {
193 int i;
194 int n = lua_gettop(L); /* number of elements to pack */
195 lua_createtable(L, n, 1); /* create result table */
196 lua_insert(L, 1); /* put it at index 1 */
197 for (i = n; i >= 1; i--) /* assign elements */
198 lua_rawseti(L, 1, i);
199 lua_pushinteger(L, n);
200 lua_setfield(L, 1, "n"); /* t.n = number of elements */
201 return 1; /* return table */
202}
203
204
205static int unpack (lua_State *L) {
206 TabA ta;
207 lua_Integer i, e;
208 lua_Unsigned n;
209 checktab(L, 1, &ta);
210 i = luaL_optinteger(L, 2, 1);
211 e = luaL_opt(L, luaL_checkinteger, 3, luaL_len(L, 1));
212 if (i > e) return 0; /* empty range */
213 n = (lua_Unsigned)e - i; /* number of elements minus 1 (avoid overflows) */
214 if (n >= (unsigned int)INT_MAX || !lua_checkstack(L, (int)(++n)))
215 return luaL_error(L, "too many results to unpack");
216 do { /* must have at least one element */
217 (*ta.geti)(L, 1, i); /* push arg[i..e] */
218 } while (i++ < e);
219
220 return (int)n;
221}
222
223/* }====================================================== */
224
225
226
227/*
228** {======================================================
229** Quicksort
230** (based on 'Algorithms in MODULA-3', Robert Sedgewick;
231** Addison-Wesley, 1993.)
232** =======================================================
233*/
234
235
236static void set2 (lua_State *L, TabA *ta, int i, int j) {
237 (*ta->seti)(L, 1, i);
238 (*ta->seti)(L, 1, j);
239}
240
241static int sort_comp (lua_State *L, int a, int b) {
242 if (!lua_isnil(L, 2)) { /* function? */
243 int res;
244 lua_pushvalue(L, 2);
245 lua_pushvalue(L, a-1); /* -1 to compensate function */
246 lua_pushvalue(L, b-2); /* -2 to compensate function and 'a' */
247 lua_call(L, 2, 1);
248 res = lua_toboolean(L, -1);
249 lua_pop(L, 1);
250 return res;
251 }
252 else /* a < b? */
253 return lua_compare(L, a, b, LUA_OPLT);
254}
255
256static void auxsort (lua_State *L, TabA *ta, int l, int u) {
257 while (l < u) { /* for tail recursion */
258 int i, j;
259 /* sort elements a[l], a[(l+u)/2] and a[u] */
260 (*ta->geti)(L, 1, l);
261 (*ta->geti)(L, 1, u);
262 if (sort_comp(L, -1, -2)) /* a[u] < a[l]? */
263 set2(L, ta, l, u); /* swap a[l] - a[u] */
264 else
265 lua_pop(L, 2);
266 if (u-l == 1) break; /* only 2 elements */
267 i = (l+u)/2;
268 (*ta->geti)(L, 1, i);
269 (*ta->geti)(L, 1, l);
270 if (sort_comp(L, -2, -1)) /* a[i]<a[l]? */
271 set2(L, ta, i, l);
272 else {
273 lua_pop(L, 1); /* remove a[l] */
274 (*ta->geti)(L, 1, u);
275 if (sort_comp(L, -1, -2)) /* a[u]<a[i]? */
276 set2(L, ta, i, u);
277 else
278 lua_pop(L, 2);
279 }
280 if (u-l == 2) break; /* only 3 elements */
281 (*ta->geti)(L, 1, i); /* Pivot */
282 lua_pushvalue(L, -1);
283 (*ta->geti)(L, 1, u-1);
284 set2(L, ta, i, u-1);
285 /* a[l] <= P == a[u-1] <= a[u], only need to sort from l+1 to u-2 */
286 i = l; j = u-1;
287 for (;;) { /* invariant: a[l..i] <= P <= a[j..u] */
288 /* repeat ++i until a[i] >= P */
289 while ((*ta->geti)(L, 1, ++i), sort_comp(L, -1, -2)) {
290 if (i>=u) luaL_error(L, "invalid order function for sorting");
291 lua_pop(L, 1); /* remove a[i] */
292 }
293 /* repeat --j until a[j] <= P */
294 while ((*ta->geti)(L, 1, --j), sort_comp(L, -3, -1)) {
295 if (j<=l) luaL_error(L, "invalid order function for sorting");
296 lua_pop(L, 1); /* remove a[j] */
297 }
298 if (j<i) {
299 lua_pop(L, 3); /* pop pivot, a[i], a[j] */
300 break;
301 }
302 set2(L, ta, i, j);
303 }
304 (*ta->geti)(L, 1, u-1);
305 (*ta->geti)(L, 1, i);
306 set2(L, ta, u-1, i); /* swap pivot (a[u-1]) with a[i] */
307 /* a[l..i-1] <= a[i] == P <= a[i+1..u] */
308 /* adjust so that smaller half is in [j..i] and larger one in [l..u] */
309 if (i-l < u-i) {
310 j=l; i=i-1; l=i+2;
311 }
312 else {
313 j=i+1; i=u; u=j-2;
314 }
315 auxsort(L, ta, j, i); /* call recursively the smaller one */
316 } /* repeat the routine for the larger one */
317}
318
319static int sort (lua_State *L) {
320 TabA ta;
321 int n = (int)aux_getn(L, 1, &ta);
322 luaL_checkstack(L, 50, ""); /* assume array is smaller than 2^50 */
323 if (!lua_isnoneornil(L, 2)) /* is there a 2nd argument? */
324 luaL_checktype(L, 2, LUA_TFUNCTION);
325 lua_settop(L, 2); /* make sure there are two arguments */
326 auxsort(L, &ta, 1, n);
327 return 0;
328}
329
330/* }====================================================== */
331
332
333static const luaL_Reg tab_funcs[] = {
334 {"concat", tconcat},
335#if defined(LUA_COMPAT_MAXN)
336 {"maxn", maxn},
337#endif
338 {"insert", tinsert},
339 {"pack", pack},
340 {"unpack", unpack},
341 {"remove", tremove},
342 {"move", tmove},
343 {"sort", sort},
344 {NULL, NULL}
345};
346
347
348LUAMOD_API int luaopen_table (lua_State *L) {
349 luaL_newlib(L, tab_funcs);
350#if defined(LUA_COMPAT_UNPACK)
351 /* _G.unpack = table.unpack */
352 lua_getfield(L, -1, "unpack");
353 lua_setglobal(L, "unpack");
354#endif
355 return 1;
356}
357
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