Pack 15 Code & identifiers

Code & identifiers is about the shapes of source code: hex literals, snake_case and CONSTANT_CASE names, function calls, env-style key and value pairs, import paths and query-string parameters. Naming rules are strict, so the traps look like real typos.

You start with hex literals like 0x1a2b, where 0X1 is spared. Then come names like foo_bar and MAX_SIZE, calls like f(a,b), pairs like PORT=3000, dotted paths like os.path and parameters like id=5. Most boards come down to one idea: a part, then more parts joined by a separator, with no separator at either end.

Every level also has hidden checks: words you don’t see. Passing the words on screen solves a level; passing the hidden checks too ranks it.

That idea comes back in Web & systems. The Real-world validators track explains it in more detail.