feat: it works!

pkg/convert/saccharine_to_lambda.go

@@ -47,6 +47,51 @@ func convertApplication(n *ast.Application) lambda.Expression {
 	return result
 }
 
+func reduceLet(s *ast.LetStatement, e lambda.Expression) lambda.Expression {
+	var value lambda.Expression
+
+	if len(s.Parameters) == 0 {
+		value = SaccharineToLambda(s.Body)
+	} else {
+		value = convertAbstraction(ast.NewAbstraction(s.Parameters, s.Body))
+	}
+
+	return lambda.NewApplication(
+		lambda.NewAbstraction(s.Name, e),
+		value,
+	)
+}
+
+func reduceDeclare(s *ast.DeclareStatement, e lambda.Expression) lambda.Expression {
+	freshVar := lambda.GenerateFreshName(lambda.GetFreeVariables(e))
+
+	return lambda.NewApplication(
+		lambda.NewAbstraction(freshVar, e),
+		SaccharineToLambda(s.Value),
+	)
+}
+
+func reduceStatement(s ast.Statement, e lambda.Expression) lambda.Expression {
+	switch s := s.(type) {
+	case *ast.DeclareStatement:
+		return reduceDeclare(s, e)
+	case *ast.LetStatement:
+		return reduceLet(s, e)
+	default:
+		panic(fmt.Errorf("unknown statement type: %v", s))
+	}
+}
+
+func convertClause(n *ast.Clause) lambda.Expression {
+	result := SaccharineToLambda(n.Returns)
+
+	for i := len(n.Statements) - 1; i >= 0; i-- {
+		result = reduceStatement(n.Statements[i], result)
+	}
+
+	return result
+}
+
 func SaccharineToLambda(n ast.Expression) lambda.Expression {
 	switch n := n.(type) {
 	case *ast.Atom:
@@ -55,6 +100,8 @@ func SaccharineToLambda(n ast.Expression) lambda.Expression {
 		return convertAbstraction(n)
 	case *ast.Application:
 		return convertApplication(n)
+	case *ast.Clause:
+		return convertClause(n)
 	default:
 		panic(fmt.Errorf("unknown expression type: %T", n))
 	}