parser: Refactor coagulated binops as postfix operators

This allows them to intermingle more nicely with `Try`

src/lexer.rs

@@ -46,9 +46,7 @@ impl<'t> Lexer<'t> {
     fn advance_tail(&mut self) {
         match self.iter.peek() {
             Some(&(idx, _)) => self.tail = idx as u32,
-            None => {
-                self.tail = self.text.len() as _;
-            }
+            None => self.tail = self.text.len() as _,
         }
     }