Add redis support for distributed caching

vendor/github.com/yuin/gopher-lua/ast/ast.go

@@ -0,0 +1,29 @@
+package ast
+
+type PositionHolder interface {
+	Line() int
+	SetLine(int)
+	LastLine() int
+	SetLastLine(int)
+}
+
+type Node struct {
+	line     int
+	lastline int
+}
+
+func (self *Node) Line() int {
+	return self.line
+}
+
+func (self *Node) SetLine(line int) {
+	self.line = line
+}
+
+func (self *Node) LastLine() int {
+	return self.lastline
+}
+
+func (self *Node) SetLastLine(line int) {
+	self.lastline = line
+}