copilot try

Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>

Author: tiye

src/s_expr.mbt

@@ -53,7 +53,10 @@ fn format_lispy_expr(self : Cirru, indent : Int) -> String raise FormatError {
       } else {
         let s0 = token[0]
         if s0 == '|' || s0 == '"' {
-          let sliced = (try? token[1:]).unwrap().to_string()
+          if token.length() < 2 {
+            raise FormatError("token too short to slice: \{token}")
+          }
+          let sliced = (try? token[1:]).unwrap_or_else(|| raise FormatError("failed to slice token: \{token}")).to_string()
           "\"" + escape_string(sliced) + "\""
         } else if token.contains(" ") ||
           token.contains("\n") ||