Implement numeric pattern matching

schala-lang/src/eval.rs

@@ -226,13 +226,30 @@ impl<'a> State<'a> {
                     inner_state.values.insert(bv.clone(), ValueEntry::Binding { constant: true, val: val.clone() });
                   }
                 }
+
+                if let Some(guard_expr) = alt.guard {
+                  let evaled_guard = inner_state.expression(guard_expr.to_node());
+                  println!("EVALED GUARD: {:?}", evaled_guard);
+                  //continue
+                }
+
                 return inner_state.block(alt.item)
               }
             }
-            return Err(format!("No matches found"));
+            return Err(format!("Failed pattern match"));
           },
-          Node::PrimTuple { .. } => Err(format!("Tuples don't work")),
+          Node::PrimTuple { .. } => Err(format!("Tuples not implemented")), //TODO make a distinction between not yet implemented and an actual runtime error
-          Node::Expr(e) => Err(format!("Exprs don't work {:?}", e))
+          Node::Expr(e) => {
+            for alt in alternatives {
+              match alt.guard {
+                Some(ref guard_expr) if alt.tag.is_none() => {
+                  return self.block(alt.item)
+                },
+                _ => ()
+              }
+            }
+            return Err(format!("Failed pattern match"));
+          }
         },
         UnimplementedSigilValue => Err(format!("Sigil value eval not implemented"))
       }