Gotchas

Currently no known gotchas.

Every source-level trap that once needed memorisation is now reported by the compiler itself: nurlc emits an error: / warning: with a pointing caret and the concrete cure inline, so a wrong program tells you what to fix at the point you wrote it. If you hit a NURL compile error, the diagnostic is the source of truth — read it rather than guessing.

The few things that are not surprises but fixed properties of the language or its runtime live in their proper homes, not here:

• Grammar properties — prefix notation, every operator's fixed arity,

^ being return (and ^^ being XOR): LIMITATIONS.md → Grammar and the authoritative ../spec/grammar.ebnf.

• Ownership & lifetimes — single-owner auto-drop, and the borrow

checker's escape analysis for : ~-mutable closure captures: MEMORY.md.

• Async/fiber runtime — non-blocking handle flipping, runtime_run

blocking semantics, and runtime-maintainer notes: ASYNC.md → Operational caveats.

If a real source-level surprise turns up that the compiler does not yet diagnose, that is a compiler bug: it belongs in a compiler/tests/should_fail_*.nu regression and a new diagnostic, after which it stays out of this page.