/*
** Calls a runtime capture. Returns number of captures removed by
** the call, including the initial Cgroup. (Captures to be added are
** on the Lua stack.)
*/
int runtimecap (CapState *cs, Capture *close, const char *s, int *rem) {
int n, id;
lua_State *L = cs->L;
int otop = lua_gettop(L);
Capture *open = findopen(close);
assert(captype(open) == Cgroup);
id = finddyncap(open, close); /* get first dynamic capture argument */
close->kind = Cclose; /* closes the group */
close->s = s;
cs->cap = open; cs->valuecached = 0; /* prepare capture state */
luaL_checkstack(L, 4, "too many runtime captures");
pushluaval(cs); /* push function to be called */
lua_pushvalue(L, SUBJIDX); /* push original subject */
lua_pushinteger(L, s - cs->s + 1); /* push current position */
n = pushnestedvalues(cs, 0); /* push nested captures */
lua_call(L, n + 2, LUA_MULTRET); /* call dynamic function */
if (id > 0) { /* are there old dynamic captures to be removed? */
int i;
for (i = id; i <= otop; i++)
lua_remove(L, id); /* remove old dynamic captures */
*rem = otop - id + 1; /* total number of dynamic captures removed */
}
else
*rem = 0; /* no dynamic captures removed */
return (int)(close - open); /* number of captures of all kinds removed */
}
/*
** Remove dynamic captures from the Lua stack (called in case of failure)
*/
static int removedyncap (lua_State *L, Capture *capture,
int level, int last) {
int id = finddyncap(capture + level, capture + last); /* index of 1st cap. */
int top = lua_gettop(L);
if (id == 0) return 0; /* no dynamic captures? */
lua_settop(L, id - 1); /* remove captures */
return top - id + 1; /* number of values removed */
}
