From c0289f238fcd7594be1e0bf70268a1c227219a4b Mon Sep 17 00:00:00 2001
From: greg <greg.shuflin@protonmail.com>
Date: Sat, 10 Mar 2018 22:10:13 -0800
Subject: [PATCH] Starting on macro work

---
 src/schala_lang/autoparser.rs | 31 +++++++++++++++++++++----------
 1 file changed, 21 insertions(+), 10 deletions(-)

diff --git a/src/schala_lang/autoparser.rs b/src/schala_lang/autoparser.rs
index da1c27c..93eb16f 100644
--- a/src/schala_lang/autoparser.rs
+++ b/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)));
 }