static void add_s (MatchState *ms, luaL_Buffer *b,
const lua_WChar *s, const lua_WChar *e) {
lua_State *L = ms->L;
if (lua_iswstring(L, 3)) {
const lua_WChar *news = lua_towstring(L, 3);
size_t l = lua_strlen(L, 3);
size_t i;
for (i=0; i<l; i++) {
if (news[i] != ESC)
luaL_putwchar(b, news[i]);
else {
i++; /* skip ESC */
if (!iswdigit(news[i]))
luaL_putwchar(b, news[i]);
else {
int level = check_capture(ms, news[i]);
push_onecapture(ms, level);
luaL_addvalue(b); /* add capture to accumulated result */
}
}
}
}
else { /* is a function */
int n;
lua_pushvalue(L, 3);
n = push_captures(ms, s, e);
lua_call(L, n, 1);
if (lua_iswstring(L, -1))
luaL_addvalue(b); /* add return to accumulated result */
else
lua_pop(L, 1); /* function result is not a string: pop it */
}
}
static void wadd_value (WMatchState *ms, luaL_Buffer *b, const lua_WChar *s,
const lua_WChar *e) {
lua_State *L = ms->L;
switch (lua_type(L, 3)) {
case LUA_TNUMBER:
case LUA_TSTRING:
case LUA_TWSTRING: {
wadd_s(ms, b, s, e);
return;
}
case LUA_TFUNCTION: {
int n;
lua_pushvalue(L, 3);
n = wpush_captures(ms, s, e);
lua_call(L, n, 1);
break;
}
case LUA_TTABLE: {
wpush_onecapture(ms, 0, s, e);
lua_gettable(L, 3);
break;
}
default: {
luaL_argerror(L, 3, "string/wstring/function/table expected");
return;
}
}
if (!lua_toboolean(L, -1)) { /* nil or false? */
lua_pop(L, 1);
lua_pushlwstring(L, s, e - s); /* keep original text */
}
else if (!lua_iswstring(L, -1))
luaL_error(L, "invalid replacement value (a %s)", luaL_typename(L, -1));
luaL_addvalue(b); /* add result to accumulator */
}
static int str_gsub (lua_State *L) {
size_t srcl;
const lua_WChar *src = luaL_checklwstring(L, 1, &srcl);
const lua_WChar *p = luaL_checkwstring(L, 2);
int max_s = luaL_optint(L, 4, srcl+1);
int anchor = (*p == '^') ? (p++, 1) : 0;
int n = 0;
MatchState ms;
luaL_Buffer b;
luaL_argcheck(L,
lua_gettop(L) >= 3 && (lua_iswstring(L, 3) || lua_isfunction(L, 3)),
3, "string or function expected");
luaL_wbuffinit(L, &b);
ms.L = L;
ms.src_init = src;
ms.src_end = src+srcl;
while (n < max_s) {
const lua_WChar *e;
ms.level = 0;
e = match(&ms, src, p);
if (e) {
n++;
add_s(&ms, &b, src, e);
}
if (e && e>src) /* non empty match? */
src = e; /* skip it */
else if (src < ms.src_end)
luaL_putwchar(&b, *src++);
else break;
if (anchor) break;
}
luaL_addlwstring(&b, src, ms.src_end-src);
luaL_pushresult(&b);
lua_pushnumber(L, n); /* number of substitutions */
return 2;
}