/**
* Reduce the size of the action tables, if possible, by making use
* of defaults.
*
* In this version, we take the most frequent REDUCE action and make
* it the default.
*/
function CompressTables()
{
for ($i = 0; $i < $this->nstate; $i++) {
$stp = $this->sorted[$i]->data;
$nbest = 0;
$rbest = 0;
for ($ap = $stp->ap; $ap; $ap = $ap->next) {
if ($ap->type != PHP_ParserGenerator_Action::REDUCE) {
continue;
}
$rp = $ap->x;
if ($rp === $rbest) {
continue;
}
$n = 1;
for ($ap2 = $ap->next; $ap2; $ap2 = $ap2->next) {
if ($ap2->type != PHP_ParserGenerator_Action::REDUCE) {
continue;
}
$rp2 = $ap2->x;
if ($rp2 === $rbest) {
continue;
}
if ($rp2 === $rp) {
$n++;
}
}
if ($n > $nbest) {
$nbest = $n;
$rbest = $rp;
}
}
/* Do not make a default if the number of rules to default
** is not at least 1 */
if ($nbest < 1) {
continue;
}
/* Combine matching REDUCE actions into a single default */
for ($ap = $stp->ap; $ap; $ap = $ap->next) {
if ($ap->type == PHP_ParserGenerator_Action::REDUCE && $ap->x === $rbest) {
break;
}
}
if ($ap === 0) {
throw new Exception('$ap is not an object');
}
$ap->sp = PHP_ParserGenerator_Symbol::Symbol_new("{default}");
for ($ap = $ap->next; $ap; $ap = $ap->next) {
if ($ap->type == PHP_ParserGenerator_Action::REDUCE && $ap->x === $rbest) {
$ap->type = PHP_ParserGenerator_Action::NOT_USED;
}
}
$stp->ap = PHP_ParserGenerator_Action::Action_sort($stp->ap);
}
}
/**
* create linked list of PHP_ParserGenerator_Actions
*
* @param PHP_ParserGenerator_Action|null
* @param int one of the class constants from PHP_ParserGenerator_Action
* @param PHP_ParserGenerator_Symbol
* @param PHP_ParserGenerator_State|PHP_ParserGenerator_Rule
*/
public static function Action_add(&$app, $type, PHP_ParserGenerator_Symbol $sp, $arg)
{
$new = new PHP_ParserGenerator_Action();
$new->next = $app;
$app = $new;
$new->type = $type;
$new->sp = $sp;
$new->x = $arg;
echo ' Adding ';
$new->display();
}