From ab902b4ac67f62bceeab43da51dc1ac1229b38bd Mon Sep 17 00:00:00 2001
From: Vitaliy Filippov <vitalif@yourcmc.ru>
Date: Sat, 20 Apr 2013 14:58:25 +0400
Subject: [PATCH] Compress reduce rules

---
 lime.php         | 16 ++++++++++++++++
 parse_engine.php | 12 +++++++-----
 2 files changed, 23 insertions(+), 5 deletions(-)

diff --git a/lime.php b/lime.php
index 603fe3b..bd5a5cc 100755
--- a/lime.php
+++ b/lime.php
@@ -666,9 +666,25 @@ class lime {
 			throw new Bug($this->expect_conflicts .' conflicts expected, got ' . $this->conflicts);
 		}
 
+		$this->compress($i);
+
 		return $this->lang->ptab_to_class($this->parser_class, compact('a', 'qi', 'i', 'd'));
 	}
 
+	function compress(&$i) {
+		foreach ($i as &$inst) {
+			$act = reset($inst);
+			if (substr($act, 0, 2) == 'r ') {
+				foreach ($inst as $k => $a) {
+					if ($a !== $act) {
+						continue(2);
+					}
+				}
+				$inst = array('' => $act);
+			}
+		}
+	}
+
 	function rule_table() {
 		$s = array();
 
diff --git a/parse_engine.php b/parse_engine.php
index 1ca6b3c..1bad776 100644
--- a/parse_engine.php
+++ b/parse_engine.php
@@ -263,11 +263,13 @@ class parse_engine {
 
 	private function step_for($type) {
 		$row = $this->current_row();
-		if (!isset($row[$type])) {
-			return array('e', $this->stack->q);
+		if (isset($row[$type])) {
+			return explode(' ', $row[$type]);
 		}
-
-		return explode(' ', $row[$type]);
+		if (isset($row[''])) {
+			return explode(' ', $row['']);
+		}
+		return array('e', $this->stack->q);
 	}
 
 	private function get_steps() {
@@ -281,7 +283,7 @@ class parse_engine {
 
 			list($opcode) = explode(' ', $row, 2);
 			if ($opcode != 'e') {
-				$out[] = $type;
+				$out[] = $type === '' ? '$default' : $type;
 			}
 		}