start refactoring gui

pkg/utils/string_stack.go

@@ -0,0 +1,27 @@
+package utils
+
+type StringStack struct {
+	stack []string
+}
+
+func (self *StringStack) Push(s string) {
+	self.stack = append(self.stack, s)
+}
+
+func (self *StringStack) Pop() string {
+	if len(self.stack) == 0 {
+		return ""
+	}
+	n := len(self.stack) - 1
+	last := self.stack[n]
+	self.stack = self.stack[:n]
+	return last
+}
+
+func (self *StringStack) IsEmpty() bool {
+	return len(self.stack) == 0
+}
+
+func (self *StringStack) Clear() {
+	self.stack = []string{}
+}