An alternation picks its arms evenly, so {a|a|b} was a covert 3:1 skew — a
third spelling of what a choice's weight is for, reachable only by
experiment. The check runs over the arms as written, before a reference arm
is let through, so {..a|..a} is caught too.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
A builtin could be spelled as prep (args parsed once, at compile) or call
(args parsed per render), reaching the same closure by two routes. Nothing
enforced the "exactly one of" invariant: supplying both silently dropped
call, supplying neither compiled and then panicked inside a render, and a
test existed only to police it.
prep does everything call did, so it is now the one spelling. The zero-arg
shapes the README already names — a derivation reads the output emitted so
far, a generator reads only the rng — lift through derive and generate, so
the registry reads as that taxonomy. iban stops looking its country up per
render.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
M
Mikael Göransson