Converted all parser methods to use the annotation

schala-lang/language/src/parsing.rs

@@ -83,32 +83,6 @@ macro_rules! expect {
   }
 }
 
-
-macro_rules! parse_method {
-  ($name:ident(&mut $self:ident) -> $type:ty $body:block) => {
-    fn $name(&mut $self) -> $type {
-      let next_token = $self.peek_with_token_offset();
-      let record = ParseRecord {
-        production_name: stringify!($name).to_string(),
-        next_token: format!("{}", next_token.to_string_with_metadata()),
-        level: $self.parse_level,
-      };
-      $self.parse_level += 1;
-      $self.parse_record.push(record);
-      let result = { $body };
-
-      if $self.parse_level != 0 {
-        $self.parse_level -= 1;
-      }
-      match result {
-        Err(ParseError { token: None, msg }) =>
-          Err(ParseError { token: Some(next_token), msg }),
-        _ => result
-      }
-    }
-  };
-}
-
 macro_rules! delimited {
   ($self:expr, $start:pat, $parse_fn:ident, $( $delim:pat )|+, $end:pat, nonstrict) => {
     delimited!($self, $start, $parse_fn, $( $delim )|*, $end, false)
@@ -266,7 +240,8 @@ enumerator :=  identifier '<-' expression | identifier '=' expression //TODO add
 */
 
 impl Parser {
-  parse_method!(program(&mut self) -> ParseResult<AST> {
+  #[recursive_descent_method]
+  fn program(&mut self) -> ParseResult<AST> {
     let mut statements = Vec::new();
     loop {
       match self.peek() {
@@ -279,9 +254,10 @@ impl Parser {
       }
     }
     Ok(AST(statements))
-  });
+  }
 
-  parse_method!(statement(&mut self) -> ParseResult<Statement> {
+  #[recursive_descent_method]
+  fn statement(&mut self) -> ParseResult<Statement> {
     //TODO handle error recovery here
     match self.peek() {
       Keyword(Type) => self.type_declaration().map(|decl| { Statement::Declaration(decl) }),
@@ -291,14 +267,16 @@ impl Parser {
       Keyword(Impl) => self.impl_declaration().map(|decl| Statement::Declaration(decl)),
       _ => self.expression().map(|expr| { Statement::ExpressionStatement(expr) } ),
     }
-  });
+  }
 
-  parse_method!(type_declaration(&mut self) -> ParseResult<Declaration> {
+  #[recursive_descent_method]
+  fn type_declaration(&mut self) -> ParseResult<Declaration> {
     expect!(self, Keyword(Type));
     self.type_declaration_body()
-  });
+  }
 
-  parse_method!(type_declaration_body(&mut self) -> ParseResult<Declaration> {
+  #[recursive_descent_method]
+  fn type_declaration_body(&mut self) -> ParseResult<Declaration> {
     if let Keyword(Alias) = self.peek() {
       self.type_alias()
     } else {
@@ -313,17 +291,19 @@ impl Parser {
       let body = self.type_body()?;
       Ok(Declaration::TypeDecl { name, body, mutable})
     }
-  });
+  }
 
-  parse_method!(type_alias(&mut self) -> ParseResult<Declaration> {
+  #[recursive_descent_method]
+  fn type_alias(&mut self) -> ParseResult<Declaration> {
     expect!(self, Keyword(Alias));
     let alias = self.identifier()?;
     expect!(self, Operator(ref c) if **c == "=");
     let original = self.identifier()?;
     Ok(Declaration::TypeAlias(alias, original))
-  });
+  }
 
-  parse_method!(type_body(&mut self) -> ParseResult<TypeBody> {
+  #[recursive_descent_method]
+  fn type_body(&mut self) -> ParseResult<TypeBody> {
     let mut variants = Vec::new();
     variants.push(self.variant_specifier()?);
     loop {
@@ -335,9 +315,10 @@ impl Parser {
       }
     }
     Ok(TypeBody(variants))
-  });
+  }
 
-  parse_method!(variant_specifier(&mut self) -> ParseResult<Variant> {
+  #[recursive_descent_method]
+  fn variant_specifier(&mut self) -> ParseResult<Variant> {
     use self::Variant::*;
 
     let name = self.identifier()?;
@@ -352,16 +333,18 @@ impl Parser {
       },
       _ => Ok(UnitStruct(name))
     }
-  });
+  }
 
-  parse_method!(typed_identifier(&mut self) -> ParseResult<(Rc<String>, TypeIdentifier)> {
+  #[recursive_descent_method]
+  fn typed_identifier(&mut self) -> ParseResult<(Rc<String>, TypeIdentifier)> {
     let identifier = self.identifier()?;
     expect!(self, Colon);
     let type_name = self.type_name()?;
     Ok((identifier, type_name))
-  });
+  }
 
-  parse_method!(func_declaration(&mut self) -> ParseResult<Declaration> {
+  #[recursive_descent_method]
+  fn func_declaration(&mut self) -> ParseResult<Declaration> {
     let signature = self.func_signature()?;
     if let LCurlyBrace = self.peek() {
       let statements = delimited!(self, LCurlyBrace, statement, Newline | Semicolon, RCurlyBrace, nonstrict);
@@ -369,9 +352,10 @@ impl Parser {
     } else {
       Ok(Declaration::FuncSig(signature))
     }
-  });
+  }
 
-  parse_method!(func_signature(&mut self) -> ParseResult<Signature> {
+  #[recursive_descent_method]
+  fn func_signature(&mut self) -> ParseResult<Signature> {
     expect!(self, Keyword(Func));
     let (name, operator) = match self.peek() {
       Operator(s) => {
@@ -387,19 +371,20 @@ impl Parser {
       _ => None,
     };
     Ok(Signature { name, operator, params, type_anno })
-  });
+  }
 
-  parse_method!(formal_param(&mut self) -> ParseResult<FormalParam> {
+  #[recursive_descent_method]
+  fn formal_param(&mut self) -> ParseResult<FormalParam> {
     let name = self.identifier()?;
     let ty = match self.peek() {
       Colon => Some(self.type_anno()?),
       _ => None
     };
     Ok((name, ty))
-  });
+  }
-
-  parse_method!(binding_declaration(&mut self) -> ParseResult<Declaration> {
 
+  #[recursive_descent_method]
+  fn binding_declaration(&mut self) -> ParseResult<Declaration> {
     expect!(self, Keyword(Kw::Let));
     let constant = match self.peek() {
       Keyword(Kw::Mut) => {
@@ -413,20 +398,23 @@ impl Parser {
     let expr = self.expression()?;
 
     Ok(Declaration::Binding { name, constant, expr })
-  });
+  }
 
-  parse_method!(interface_declaration(&mut self) -> ParseResult<Declaration> {
+  #[recursive_descent_method]
+  fn interface_declaration(&mut self) -> ParseResult<Declaration> {
     expect!(self, Keyword(Interface));
     let name = self.identifier()?;
     let signatures = self.signature_block()?;
     Ok(Declaration::Interface { name, signatures })
-  });
+  }
 
-  parse_method!(signature_block(&mut self) -> ParseResult<Vec<Signature>> {
+  #[recursive_descent_method]
+  fn signature_block(&mut self) -> ParseResult<Vec<Signature>> {
     Ok(delimited!(self, LCurlyBrace, func_signature, Newline | Semicolon, RCurlyBrace, nonstrict))
-  });
+  }
 
-  parse_method!(impl_declaration(&mut self) -> ParseResult<Declaration> {
+  #[recursive_descent_method]
+  fn impl_declaration(&mut self) -> ParseResult<Declaration> {
     expect!(self, Keyword(Impl));
     let first = self.type_name()?;
     let second = if let Keyword(For) = self.peek() {
@@ -449,13 +437,15 @@ impl Parser {
       (first, None) => Declaration::Impl { type_name: first, interface_name: None, block }
     };
     Ok(result)
-  });
+  }
 
-  parse_method!(decl_block(&mut self) -> ParseResult<Vec<Declaration>> {
+  #[recursive_descent_method]
+  fn decl_block(&mut self) -> ParseResult<Vec<Declaration>> {
     Ok(delimited!(self, LCurlyBrace, func_declaration, Newline | Semicolon, RCurlyBrace, nonstrict))
-  });
+  }
 
-  parse_method!(expression(&mut self) -> ParseResult<Expression> {
+  #[recursive_descent_method]
+  fn expression(&mut self) -> ParseResult<Expression> {
     let mut expr_body = self.precedence_expr(BinOp::min_precedence())?;
     let type_anno = match self.peek() {
       Colon => Some(self.type_anno()?),
@@ -466,22 +456,25 @@ impl Parser {
     }
     expr_body.1 = type_anno;
     Ok(expr_body)
-  });
+  }
 
-  parse_method!(type_anno(&mut self) -> ParseResult<TypeIdentifier> {
+  #[recursive_descent_method]
+  fn type_anno(&mut self) -> ParseResult<TypeIdentifier> {
     expect!(self, Colon);
     self.type_name()
-  });
+  }
 
-  parse_method!(type_name(&mut self) -> ParseResult<TypeIdentifier> {
+  #[recursive_descent_method]
+  fn type_name(&mut self) -> ParseResult<TypeIdentifier> {
     use self::TypeIdentifier::*;
     Ok(match self.peek() {
       LParen => Tuple(delimited!(self, LParen, type_name, Comma, RParen)),
       _ => Singleton(self.type_singleton_name()?),
     })
-  });
+  }
 
-  parse_method!(type_singleton_name(&mut self) -> ParseResult<TypeSingletonName> {
+  #[recursive_descent_method]
+  fn type_singleton_name(&mut self) -> ParseResult<TypeSingletonName> {
     Ok(TypeSingletonName {
       name: self.identifier()?,
       params: match self.peek() {
@@ -489,7 +482,7 @@ impl Parser {
         _ => vec![],
       }
     })
-  });
+  }
 
   // this implements Pratt parsing, see http://journal.stuffwithstuff.com/2011/03/19/pratt-parsers-expression-parsing-made-easy/
   fn precedence_expr(&mut self, precedence: i32) -> ParseResult<Expression> {
@@ -522,7 +515,8 @@ impl Parser {
     Ok(lhs)
   }
 
-  parse_method!(prefix_expr(&mut self) -> ParseResult<Expression> {
+  #[recursive_descent_method]
+  fn prefix_expr(&mut self) -> ParseResult<Expression> {
     match self.peek() {
       Operator(ref op) if PrefixOp::is_prefix(&*op) => {
         let sigil = match self.next() {
@@ -536,9 +530,10 @@ impl Parser {
       },
       _ => self.call_expr()
     }
-  });
+  }
 
-  parse_method!(call_expr(&mut self) -> ParseResult<Expression> {
+  #[recursive_descent_method]
+  fn call_expr(&mut self) -> ParseResult<Expression> {
     let index  = self.index_expr()?;
     Ok(if let LParen = self.peek() {
       let arguments = delimited!(self, LParen, expression, Comma, RParen);
@@ -546,9 +541,10 @@ impl Parser {
     } else {
       index
     })
-  });
+  }
 
-  parse_method!(index_expr(&mut self) -> ParseResult<Expression> {
+  #[recursive_descent_method]
+  fn index_expr(&mut self) -> ParseResult<Expression> {
     let primary = self.primary()?;
     Ok(if let LSquareBracket = self.peek() {
       let indexers = delimited!(self, LSquareBracket, expression, Comma, RSquareBracket);
@@ -559,9 +555,10 @@ impl Parser {
     } else {
       primary
     })
-  });
+  }
 
-  parse_method!(primary(&mut self) -> ParseResult<Expression> {
+  #[recursive_descent_method]
+  fn primary(&mut self) -> ParseResult<Expression> {
     match self.peek() {
       LCurlyBrace => self.curly_brace_expr(),
       LParen => self.paren_expr(),
@@ -572,18 +569,21 @@ impl Parser {
       Identifier(_) => self.identifier_expr(),
       _ => self.literal(),
     }
-  });
+  }
 
-  parse_method!(list_expr(&mut self) -> ParseResult<Expression> {
+  #[recursive_descent_method]
+  fn list_expr(&mut self) -> ParseResult<Expression> {
     let exprs = delimited!(self, LSquareBracket, expression, Comma, RSquareBracket);
     Ok(Expression(ExpressionType::ListLiteral(exprs), None))
-  });
+  }
 
-  parse_method!(curly_brace_expr(&mut self) -> ParseResult<Expression> {
+  #[recursive_descent_method]
+  fn curly_brace_expr(&mut self) -> ParseResult<Expression> {
     self.lambda_expr()
-  });
+  }
 
-  parse_method!(lambda_expr(&mut self) -> ParseResult<Expression> {
+  #[recursive_descent_method]
+  fn lambda_expr(&mut self) -> ParseResult<Expression> {
     expect!(self, LCurlyBrace);
     let params = delimited!(self, Pipe, formal_param, Comma, Pipe);
     let mut body = Vec::new();
@@ -599,9 +599,10 @@ impl Parser {
     }
     expect!(self, RCurlyBrace);
     Ok(Expression(ExpressionType::Lambda { params, body }, None)) //TODO need to handle types somehow
-  });
+  }
 
-  parse_method!(paren_expr(&mut self) -> ParseResult<Expression> {
+  #[recursive_descent_method]
+  fn paren_expr(&mut self) -> ParseResult<Expression> {
     use self::ExpressionType::*;
     let old_struct_value = self.restrictions.no_struct_literal;
     self.restrictions.no_struct_literal = false;
@@ -615,9 +616,10 @@ impl Parser {
     };
     self.restrictions.no_struct_literal = old_struct_value;
     output
-  });
+  }
 
-  parse_method!(identifier_expr(&mut self) -> ParseResult<Expression> {
+  #[recursive_descent_method]
+  fn identifier_expr(&mut self) -> ParseResult<Expression> {
     use self::ExpressionType::*;
     let identifier = self.identifier()?;
     Ok(match self.peek() {
@@ -627,20 +629,23 @@ impl Parser {
       },
       _ => Expression(Value(identifier), None)
     })
-  });
+  }
 
-  parse_method!(record_block(&mut self) -> ParseResult<Vec<(Rc<String>, Expression)>> {
+  #[recursive_descent_method]
+  fn record_block(&mut self) -> ParseResult<Vec<(Rc<String>, Expression)>> {
     Ok(delimited!(self, LCurlyBrace, record_entry, Comma, RCurlyBrace))
-  });
+  }
 
-  parse_method!(record_entry(&mut self) -> ParseResult<(Rc<String>, Expression)> {
+  #[recursive_descent_method]
+  fn record_entry(&mut self) -> ParseResult<(Rc<String>, Expression)> {
     let field_name = self.identifier()?;
     expect!(self, Colon);
     let value = self.expression()?;
     Ok((field_name, value))
-  });
+  }
 
-  parse_method!(if_expr(&mut self) -> ParseResult<Expression> {
+  #[recursive_descent_method]
+  fn if_expr(&mut self) -> ParseResult<Expression> {
     expect!(self, Keyword(Kw::If));
     let discriminator = Box::new({
       self.restrictions.no_struct_literal = true;
@@ -656,9 +661,10 @@ impl Parser {
     });
 
     Ok(Expression(ExpressionType::IfExpression { discriminator, body }, None))
-  });
+  }
 
-  parse_method!(discriminator(&mut self) -> ParseResult<Discriminator> {
+  #[recursive_descent_method]
+  fn discriminator(&mut self) -> ParseResult<Discriminator> {
     let lhs = self.prefix_expr()?;
     let ref next = self.peek();
     Ok(if let Some(op) = BinOp::from_sigil_token(next) {
@@ -666,34 +672,38 @@ impl Parser {
     } else {
       Discriminator::Simple(lhs)
     })
-  });
+  }
 
-  parse_method!(conditional(&mut self) -> ParseResult<IfExpressionBody> {
+  #[recursive_descent_method]
+  fn conditional(&mut self) -> ParseResult<IfExpressionBody> {
     expect!(self, Keyword(Kw::Then));
     let then_clause = self.expr_or_block()?;
     let else_clause = self.else_clause()?;
     Ok(IfExpressionBody::SimpleConditional(then_clause, else_clause))
-  });
+  }
 
-  parse_method!(simple_pattern_match(&mut self) -> ParseResult<IfExpressionBody> {
+  #[recursive_descent_method]
+  fn simple_pattern_match(&mut self) -> ParseResult<IfExpressionBody> {
     expect!(self, Keyword(Kw::Is));
     let pat = self.pattern()?;
     expect!(self, Keyword(Kw::Then));
     let then_clause = self.expr_or_block()?;
     let else_clause = self.else_clause()?;
     Ok(IfExpressionBody::SimplePatternMatch(pat, then_clause, else_clause))
-  });
+  }
 
-  parse_method!(else_clause(&mut self) -> ParseResult<Option<Block>> {
+  #[recursive_descent_method]
+  fn else_clause(&mut self) -> ParseResult<Option<Block>> {
     Ok(if let Keyword(Kw::Else) = self.peek() {
       self.next();
       Some(self.expr_or_block()?)
     } else {
       None
     })
-  });
+  }
 
-  parse_method!(guard_block(&mut self) -> ParseResult<IfExpressionBody> {
+  #[recursive_descent_method]
+  fn guard_block(&mut self) -> ParseResult<IfExpressionBody> {
     //TODO - delimited! isn't sophisticated enough to do thisa
     //let guards = delimited!(self, LCurlyBrace, guard_arm, Comma, RCurlyBrace);
     expect!(self, LCurlyBrace);
@@ -714,16 +724,18 @@ impl Parser {
     }
     expect!(self, RCurlyBrace);
     Ok(IfExpressionBody::GuardList(guards))
-  });
+  }
 
-  parse_method!(guard_arm(&mut self) -> ParseResult<GuardArm> {
+  #[recursive_descent_method]
+  fn guard_arm(&mut self) -> ParseResult<GuardArm> {
     let guard = self.guard()?;
     expect!(self, Operator(ref c) if **c == "->");
     let body = self.expr_or_block()?;
     Ok(GuardArm { guard, body })
-  });
+  }
 
-  parse_method!(guard(&mut self) -> ParseResult<Guard> {
+  #[recursive_descent_method]
+  fn guard(&mut self) -> ParseResult<Guard> {
     Ok(match self.peek() {
       Keyword(Kw::Is) => {
         self.next();
@@ -740,18 +752,20 @@ impl Parser {
         Guard::HalfExpr(HalfExpr { op: None, expr })
       }
     })
-  });
+  }
 
-  parse_method!(pattern(&mut self) -> ParseResult<Pattern> {
+  #[recursive_descent_method]
+  fn pattern(&mut self) -> ParseResult<Pattern> {
     if let LParen = self.peek() {
       let tuple_pattern_variants = delimited!(self, LParen, pattern, Comma, RParen);
       Ok(Pattern::TuplePattern(tuple_pattern_variants))
     } else {
       self.simple_pattern()
     }
-  });
+  }
 
-  parse_method!(simple_pattern(&mut self) -> ParseResult<Pattern> {
+  #[recursive_descent_method]
+  fn simple_pattern(&mut self) -> ParseResult<Pattern> {
     Ok(match self.peek() {
       Identifier(_) => {
         let id = self.identifier()?;
@@ -787,7 +801,7 @@ impl Parser {
       },
       other => return ParseError::new(&format!("{:?} is not a valid Pattern", other))
     })
-  });
+  }
 
   #[recursive_descent_method]
   fn signed_number_literal(&mut self) -> ParseResult<Pattern> {
@@ -802,7 +816,8 @@ impl Parser {
     Ok(Pattern::Literal(PatternLiteral::NumPattern { neg, num: expr_type }))
   }
 
-  parse_method!(record_pattern_entry(&mut self) -> ParseResult<(Rc<String>, Pattern)> {
+  #[recursive_descent_method]
+  fn record_pattern_entry(&mut self) -> ParseResult<(Rc<String>, Pattern)> {
     let name = self.identifier()?;
     Ok(match self.peek() {
       Colon => {
@@ -812,13 +827,15 @@ impl Parser {
       },
       _ => (name.clone(), Pattern::Literal(PatternLiteral::StringPattern(name.clone())))
     })
-  });
+  }
 
-  parse_method!(block(&mut self) -> ParseResult<Block> {
+  #[recursive_descent_method]
+  fn block(&mut self) -> ParseResult<Block> {
     Ok(delimited!(self, LCurlyBrace, statement, Newline | Semicolon, RCurlyBrace, nonstrict))
-  });
+  }
 
-  parse_method!(expr_or_block(&mut self) -> ParseResult<Block> {
+  #[recursive_descent_method]
+  fn expr_or_block(&mut self) -> ParseResult<Block> {
     match self.peek() {
       LCurlyBrace => self.block(),
       _ => {
@@ -826,9 +843,10 @@ impl Parser {
         Ok(vec![Statement::ExpressionStatement(expr)])
       }
     }
-  });
+  }
 
-  parse_method!(while_expr(&mut self) -> ParseResult<Expression> {
+  #[recursive_descent_method]
+  fn while_expr(&mut self) -> ParseResult<Expression> {
     use self::ExpressionType::*;
     expect!(self, Keyword(Kw::While));
     let condition =  {
@@ -839,16 +857,18 @@ impl Parser {
     };
     let body = self.block()?;
     Ok(Expression(WhileExpression {condition, body}, None))
-  });
+  }
 
-  parse_method!(while_cond(&mut self) -> ParseResult<Option<Expression>> {
+  #[recursive_descent_method]
+  fn while_cond(&mut self) -> ParseResult<Option<Expression>> {
     Ok(match self.peek() {
       LCurlyBrace => None,
       _ => Some(self.expression()?),
     })
-  });
+  }
 
-  parse_method!(for_expr(&mut self) -> ParseResult<Expression> {
+  #[recursive_descent_method]
+  fn for_expr(&mut self) -> ParseResult<Expression> {
     expect!(self, Keyword(Kw::For));
     let enumerators = if let LCurlyBrace = self.peek() {
       delimited!(self, LCurlyBrace, enumerator, Comma | Newline, RCurlyBrace)
@@ -863,16 +883,18 @@ impl Parser {
     };
     let body = Box::new(self.for_expr_body()?);
     Ok(Expression(ExpressionType::ForExpression { enumerators, body }, None))
-  });
+  }
 
-  parse_method!(enumerator(&mut self) -> ParseResult<Enumerator> {
+  #[recursive_descent_method]
+  fn enumerator(&mut self) -> ParseResult<Enumerator> {
     let id = self.identifier()?;
     expect!(self, Operator(ref c) if **c == "<-");
     let generator = self.expression()?;
     Ok(Enumerator { id, generator })
-  });
+  }
 
-  parse_method!(for_expr_body(&mut self) -> ParseResult<ForBody> {
+  #[recursive_descent_method]
+  fn for_expr_body(&mut self) -> ParseResult<ForBody> {
     use self::ForBody::*;
     Ok(match self.peek() {
       LCurlyBrace => {
@@ -885,16 +907,18 @@ impl Parser {
       },
       _ => return ParseError::new("for expressions must end in a block or 'return'"),
     })
-  });
+  }
 
-  parse_method!(identifier(&mut self) -> ParseResult<Rc<String>> {
+  #[recursive_descent_method]
+  fn identifier(&mut self) -> ParseResult<Rc<String>> {
     match self.next() {
       Identifier(s) => Ok(s),
       p => ParseError::new(&format!("Expected an identifier, got {:?}", p)),
     }
-  });
+  }
 
-  parse_method!(literal(&mut self) -> ParseResult<Expression> {
+  #[recursive_descent_method]
+  fn literal(&mut self) -> ParseResult<Expression> {
     use self::ExpressionType::*;
     match self.peek() {
       DigitGroup(_) | HexLiteral(_) | BinNumberSigil | Period => self.number_literal(),
@@ -912,7 +936,7 @@ impl Parser {
       }
       e => ParseError::new(&format!("Expected a literal expression, got {:?}", e)),
     }
-  });
+  }
 
   #[recursive_descent_method]
   fn number_literal(&mut self) -> ParseResult<Expression> {
@@ -922,7 +946,8 @@ impl Parser {
     }
   }
 
-  parse_method!(int_literal(&mut self) -> ParseResult<Expression> {
+  #[recursive_descent_method]
+  fn int_literal(&mut self) -> ParseResult<Expression> {
     use self::ExpressionType::*;
     match self.next() {
       BinNumberSigil => {
@@ -937,9 +962,10 @@ impl Parser {
       },
       _ => return ParseError::new("Expected '0x' or '0b'"),
     }
-  });
+  }
 
-  parse_method!(float_literal(&mut self) -> ParseResult<Expression> {
+  #[recursive_descent_method]
+  fn float_literal(&mut self) -> ParseResult<Expression> {
     use self::ExpressionType::*;
     let mut digits = self.digits()?;
     if let TokenType::Period = self.peek() {
@@ -957,9 +983,10 @@ impl Parser {
         Err(e) => ParseError::new(&format!("Integer failed to parse with error: {}", e)),
       }
     }
-  });
+  }
 
-  parse_method!(digits(&mut self) -> ParseResult<String> {
+  #[recursive_descent_method]
+  fn digits(&mut self) -> ParseResult<String> {
     let mut ds = String::new();
     loop {
       match self.peek() {
@@ -969,7 +996,7 @@ impl Parser {
       }
     }
     Ok(ds)
-  });
+  }
 }
 
 fn parse_binary(digits: String) -> ParseResult<u64> {