From b71976ee5d63a504d9ba7b34e8cc4b77615513bc Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Michael=20Teichgr=C3=A4ber?= <mt@ib.wmipf.de>
Date: Mon, 30 Apr 2012 00:55:37 +0200
Subject: [PATCH] add a mechanism that makes sure only an up-to-date
 parser.leg.go can be used

---
 markdown.go | 10 ++++++++++
 parser.leg  |  4 ++++
 2 files changed, 14 insertions(+)

diff --git a/markdown.go b/markdown.go
index 2380d38..a78952d 100644
--- a/markdown.go
+++ b/markdown.go
@@ -24,6 +24,16 @@ import (
 	"strings"
 )
 
+const (
+	// If you get a build error message saying that
+	// parserIfaceVersion_N is undefined, parser.leg.go
+	// either is not present or it is out of date. You should
+	// rebuild it using
+	//	make nuke
+	//	make parser
+	needParserIfaceVersion = parserIfaceVersion_1
+)
+
 // Markdown Options:
 type Options struct {
 	Smart        bool
diff --git a/parser.leg b/parser.leg
index c79d8a5..3929c43 100644
--- a/parser.leg
+++ b/parser.leg
@@ -27,6 +27,10 @@ import (
 	"log"
 )
 
+const (
+	parserIfaceVersion_1 = iota
+)
+
 // Semantic value of a parsing action.
 type element struct {
 	key	int