feat: no constructors for expressions and statements for saccharine

pkg/saccharine/statement.go

@@ -1,7 +1,7 @@
 package saccharine
 
 type Statement interface {
-	IsStatement()
+	statement()
 }
 
 /** ------------------------------------------------------------------------- */
@@ -16,15 +16,5 @@ type DeclareStatement struct {
 	Value Expression
 }
 
-func (LetStatement) IsStatement()     {}
-func (DeclareStatement) IsStatement() {}
-
-/** ------------------------------------------------------------------------- */
-
-func NewLet(name string, parameters []string, body Expression) *LetStatement {
-	return &LetStatement{Name: name, Parameters: parameters, Body: body}
-}
-
-func NewDeclare(value Expression) *DeclareStatement {
-	return &DeclareStatement{Value: value}
-}
+func (LetStatement) statement()     {}
+func (DeclareStatement) statement() {}