feat: parse saccharine, conversion incoming

pkg/saccharine/ast/statement.go

@@ -20,3 +20,11 @@ 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}
+}