Starting on macro work

src/schala_lang/autoparser.rs

@@ -37,21 +37,32 @@ impl AutoParser {
     let ast = self.program();
     (ast, vec![])
   }
-}
-
-impl AutoParser {
   fn program(&mut self) -> ParseResult<AST> {
     let etype = self.literal()?;
     Ok(AST(vec![Statement::ExpressionStatement(Expression(etype, None))]))
   }
+}
 
-  fn literal(&mut self) -> ParseResult<ExpressionType> {
-    Ok(match self.next() {
-      Keyword(Kw::True) => ExpressionType::BoolLiteral(true),
-      Keyword(Kw::False) => ExpressionType::BoolLiteral(false),
-      _ => return ParseError::new("bad!")
+macro_rules! bnf_rule {
+  ($self:ident, $type:ty, $rule:ident := $( ($pat:pat => $e:expr) )|*) => {
+    fn $rule(&mut $self) -> ParseResult<$type> { 
+      Ok(match $self.next() {
+        $(
+          $pat => $e,
+        )*
+        _ => return ParseError::new("Not found"),
       })
     }
+  };
+}
+
+macro_rules! expand_match_arm {
+  (($pat:pat => $e:expr)) => {  $pat => $e };
+}
+
+impl AutoParser {
+  bnf_rule!(self, ExpressionType, literal := 
+    (Keyword(Kw::True) => ExpressionType::BoolLiteral(true)) | (Keyword(Kw::False) => ExpressionType::BoolLiteral(false)));
 }