1 files changed, 21 insertions, 0 deletions
diff --git a/spec/grammar/util.go b/spec/grammar/util.go
new file mode 100644
index 0000000..bf3f233
--- /dev/null
+++ b/spec/grammar/util.go
@@ -0,0 +1,21 @@
+package grammar
+
+import "strings"
+
+var rep = strings.NewReplacer(
+	`.`, `\.`,
+	`*`, `\*`,
+	`+`, `\+`,
+	`?`, `\?`,
+	`|`, `\|`,
+	`(`, `\(`,
+	`)`, `\)`,
+	`[`, `\[`,
+	`\`, `\\`,
+)
+
+// EscapePattern escapes the special characters.
+// For example, EscapePattern(`+`) returns `\+`.
+func EscapePattern(s string) string {
+	return rep.Replace(s)
+}