feat: wogihrsoiuvjsroirgj

pkg/lambda/expression.go

@@ -1,23 +1,65 @@
 package lambda
 
 type Expression interface {
-	isExpression()
+	Accept(ExpressionVisitor)
 }
 
+/** ------------------------------------------------------------------------- */
+
 type Function struct {
 	Parameter string
-	Body Expression
+	Body      Expression
 }
 
+func NewFunction(parameter string, body Expression) *Function {
+	return &Function{
+		Parameter: parameter,
+		Body:      body,
+	}
+}
+
+func (f *Function) Accept(v ExpressionVisitor) {
+	v.VisitFunction(f)
+}
+
+/** ------------------------------------------------------------------------- */
+
 type Call struct {
 	Function Expression
 	Argument Expression
 }
 
+func NewCall(function Expression, argument Expression) *Call {
+	return &Call{
+		Function: function,
+		Argument: argument,
+	}
+}
+
+func (c *Call) Accept(v ExpressionVisitor) {
+	v.VisitCall(c)
+}
+
+/** ------------------------------------------------------------------------- */
+
 type Atom struct {
 	Value string
 }
 
-func (_ Function) isExpression() {}
-func (_ Call) isExpression() {}
-func (_ Atom) isExpression() {}
+func NewAtom(name string) *Atom {
+	return &Atom{
+		Value: name,
+	}
+}
+
+func (a *Atom) Accept(v ExpressionVisitor) {
+	v.VisitAtom(a)
+}
+
+/** ------------------------------------------------------------------------- */
+
+type ExpressionVisitor interface {
+	VisitFunction(*Function)
+	VisitCall(*Call)
+	VisitAtom(*Atom)
+}