/*
** 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;
}
static int lp_matchtime (lua_State *L) {
TTree *tree;
luaL_checktype(L, 2, LUA_TFUNCTION);
tree = newroot1sib(L, TRunTime);
tree->key = addtoktable(L, 2);
return 1;
}
/*
** Fill a tree with an empty capture, using an empty (TTrue) sibling.
*/
static TTree *auxemptycap (lua_State *L, TTree *tree, int cap, int idx) {
tree->tag = TCapture;
tree->cap = cap;
tree->key = addtoktable(L, idx);
sib1(tree)->tag = TTrue;
return tree;
}
/*
** Convert value at index 'idx' to a pattern
*/
static TTree *getpatt (lua_State *L, int idx, int *len) {
TTree *tree;
switch (lua_type(L, idx)) {
case LUA_TSTRING: {
size_t slen;
const char *s = lua_tolstring(L, idx, &slen); /* get string */
if (slen == 0) /* empty? */
tree = newleaf(L, TTrue); /* always match */
else {
tree = newtree(L, 2 * (slen - 1) + 1);
fillseq(tree, TChar, slen, s); /* sequence of 'slen' chars */
}
break;
}
case LUA_TNUMBER: {
int n = lua_tointeger(L, idx);
tree = numtree(L, n);
break;
}
case LUA_TBOOLEAN: {
tree = (lua_toboolean(L, idx) ? newleaf(L, TTrue) : newleaf(L, TFalse));
break;
}
case LUA_TTABLE: {
tree = newgrammar(L, idx);
break;
}
case LUA_TFUNCTION: {
tree = newtree(L, 2);
tree->tag = TRunTime;
tree->key = addtoktable(L, idx);
sib1(tree)->tag = TTrue;
break;
}
default: {
return gettree(L, idx, len);
}
}
lua_replace(L, idx); /* put new tree into 'idx' slot */
if (len)
*len = getsize(L, idx);
return tree;
}
/*
** Create a new 'ktable' to the pattern at the top of the stack, adding
** all elements from pattern 'p' (if not 0) plus element 'idx' to it.
** Return index of new element.
*/
static int addtonewktable (lua_State *L, int p, int idx) {
newktable(L, 1);
if (p)
mergektable(L, p, NULL);
return addtoktable(L, idx);
}
/*
** Create a tree for a non-empty capture, with a body and
** optionally with an associated Lua value (at index 'labelidx' in the
** stack)
*/
static int capture_aux (lua_State *L, int cap, int labelidx) {
TTree *tree = newroot1sib(L, TCapture);
tree->cap = cap;
tree->key = addtoktable(L, labelidx);
return 1;
}
/*
** Create a non-terminal
*/
static int lp_V (lua_State *L) {
TTree *tree = newleaf(L, TOpenCall);
luaL_argcheck(L, !lua_isnoneornil(L, 1), 1, "non-nil value expected");
tree->key = addtoktable(L, 1);
return 1;
}
