/*
15.6.2.2531 [ELSE]
“bracket-else”
TOOLS EXT
Compilation: Perform the execution semantics given below.
Execution: ( “hspacesiname ...” -- )
Skipping leading spaces, parse and discard space-delimited words from the parse area,
including nested occurrences of [IF] ...
[THEN] and [IF] ...
[ELSE] ...
[THEN], until the word [THEN] has been parsed and discarded. If the parse area be-
comes exhausted, it is refilled as with REFILL. [ELSE] is an immediate word.
See: 3.4.1 Parsing, A.15.6.2.2531 [ELSE].
15.6.2.2532 [IF]
“bracket-if”
TOOLS EXT
*/
static void do_bracket_else(void)
{
/*
: [else]
1 ( initialize [if]/[else]/[then] nesting level)
begin
bl word count dup
0= ( refill input buffer) if drop drop refill 0= if ( refill failed) drop ( drop nesting level) ." error: input exhausted" cr exit then [ over ] ( continue loop) again then
0 if 2dup ." found word: " type cr then
2dup s" [if]" compare 0= if ( increase nesting level) rot 1+ rot rot then
2dup s" [else]" compare 0= if ( special-case for the nesting level) rot dup 1 = if 1- then rot rot then
s" [then]" compare 0= if ( decrease nesting level) 1- then
dup 0= until
drop ; immediate
: [if] 0= if postpone [else] then ; immediate
: [then] ; immediate
*/
/* initialize [if]/[else]/[then] nesting level */
sf_push(1);
do
{
do_bl(); do_word(); do_count();
if (!sf_top())
{
/* input exhausted, refill input buffer */
do_drop(); do_drop(); do_refill();
if (!sf_pop()) { /* 'refill' failed */ /* drop nesting level */ do_drop(); print_str(__func__);
print_str("(): input exhausted; aborting\n"); do_abort(); }
continue;
}
do_two_to_r();
do_two_r_fetch();
//sf_push((cell) "\04[if]"); do_count(); sf_push((cell) compare_word_xt); do_execute();
if (sf_pop() == 4) { if (!xmemcmp((void *) sf_pop(), "[if]", 4)) /* increase nesting level */ do_one_plus(); }
else do_drop();
do_two_r_fetch();
//sf_push((cell) "\06[else]"); do_count(); sf_push((cell) compare_word_xt); do_execute();
if (sf_pop() == 6) { if (!xmemcmp((void *) sf_pop(), "[else]", 6)) /* see if an [if] block should be terminated */ if (sf_top() == 1) do_one_minus(); }
else do_drop();
do_two_r_from();
//sf_push((cell) "\06[then]"); do_count(); sf_push((cell) compare_word_xt); do_execute();
if (sf_pop() == 6) { if (!xmemcmp((void *) sf_pop(), "[then]", 6)) /* decrease nesting level */ do_one_minus(); }
else do_drop();
}
while (sf_top());
/* drop nesting level */
do_drop();
}
// bequal reports whether the buffers have the same content.
bool
bequal(Buf *s, Buf *t)
{
return s->len == t->len && xmemcmp(s->p, t->p, s->len) == 0;
}