Alphabetize methods

src/parser.js

     })
   }
 
+  identifier() {
+    return new AST.Identifier({
+      name: this.tokenStream.eat(tokenTypes.IDENTIFIER).value,
+    })
+  }
+
   lambda() {
     let parameters = []
 
     })
   }
 
-  identifier() {
-    return new AST.Identifier({
-      name: this.tokenStream.eat(tokenTypes.IDENTIFIER).value,
-    })
   }
 
   number() {