Fix problem with parsing commas

I should probably rethink how delimited block expressions like if-blocks
(and eventually for-blocks) work

schala-lang/language/src/eval.rs

@@ -677,7 +677,7 @@ if (1, 5) {
   }
 
   #[test]
-  fn need_to_fix_parser_to_make_work() {
+  fn tuple_pattern_4() {
     let source = r#"
 if (1, 5) {
   is (10, x) -> x,

schala-lang/language/src/parsing.rs

@@ -749,19 +749,26 @@ impl Parser {
     //TODO - delimited! isn't sophisticated enough to do thisa
     //let guards = delimited!(self, LCurlyBrace, guard_arm, Comma, RCurlyBrace);
     expect!(self, LCurlyBrace);
+
     let mut guards = vec![];
     loop {
-      while let Newline = self.peek() {
-        self.next();
-      }
+      match self.peek() {
+        RCurlyBrace | EOF => break,
+        Semicolon | Newline => { self.next(); continue},
+        _ => {
           let guard_arm = self.guard_arm()?;
           guards.push(guard_arm);
-      while let Newline = self.peek() {
-        self.next();
-      }
+          loop {
             match self.peek() {
-        Comma => {self.next(); continue },
-        _ => break
+              Semicolon | Newline => { self.next(); continue; },
+              _ => break,
+            }
+          }
+          if let RCurlyBrace = self.peek() {
+            break;
+          }
+          expect!(self, Comma);
+        }
       }
     }
     expect!(self, RCurlyBrace);