fix(stdlib): rename try->attempt, ref->make_ref (#135 slice 6)

stdlib/effects.affine

@@ -18,7 +18,9 @@ extern fn read_file(path: String) -> String / io;
 extern fn write_file(path: String, content: String) -> Unit / io;
 
 // Built-in State operations
-extern fn ref<T>(x: T) -> Ref<T> / state;
+// `make_ref` (not `ref`) because `ref` is a reserved ownership keyword;
+// see #135 keyword-as-identifier slice.
+extern fn make_ref<T>(x: T) -> Ref<T> / state;
 extern fn get<T>(r: Ref<T>) -> T / state;
 extern fn set<T>(r: Ref<T>, x: T) -> Unit / state;
 

stdlib/result.affine

@@ -225,8 +225,10 @@ fn result_or<T, E>(a: Result<T, E>, b: Result<T, E>) -> Result<T, E> {
 // Error Handling Patterns
 // ============================================================================
 
-/// Try block emulation - execute function and catch panics as Err
-fn try<T>(f: () -> T) -> Result<T, String> {
+/// Try block emulation - execute function and catch panics as Err.
+/// Named `attempt` (not `try`) because `try` is a reserved keyword
+/// (try/catch/finally); see #135 keyword-as-identifier slice.
+fn attempt<T>(f: () -> T) -> Result<T, String> {
   // TODO: Requires exception handling support
   try {
     Ok(f())