/*
** Constant capture
*/
static int lp_constcapture (lua_State *L) {
int i;
int n = lua_gettop(L); /* number of values */
if (n == 0) /* no values? */
newleaf(L, TTrue); /* no capture */
else if (n == 1)
newemptycapkey(L, Cconst, 1); /* single constant capture */
else { /* create a group capture with all values */
TTree *tree = newtree(L, 1 + 3 * (n - 1) + 2);
newktable(L, n); /* create a 'ktable' for new tree */
tree->tag = TCapture;
tree->cap = Cgroup;
tree->key = 0;
tree = sib1(tree);
for (i = 1; i <= n - 1; i++) {
tree->tag = TSeq;
tree->u.ps = 3; /* skip TCapture and its sibling */
auxemptycap(sib1(tree), Cconst);
sib1(tree)->key = addtoktable(L, i);
tree = sib2(tree);
}
auxemptycap(tree, Cconst);
tree->key = addtoktable(L, i);
}
return 1;
}
/*
** Create a tree for an empty capture
*/
static TTree *newemptycap (lua_State *L, int cap) {
return auxemptycap(newtree(L, 2), cap);
}
/*
** Create a tree for an empty capture with an associated Lua value
*/
static TTree *newemptycapkey (lua_State *L, int cap, int idx) {
TTree *tree = auxemptycap(newtree(L, 2), cap);
tree->key = addtonewktable(L, 0, idx);
return tree;
}
/*
** Create a tree for an empty capture
*/
static TTree *newemptycap (lua_State *L, int cap, int idx) {
return auxemptycap(L, newtree(L, 2), cap, idx);
}
