The reason given was wrong. A dot path did reach an empty-named field:
Fake("a.") returned it, Fake("a.b.") returned a nested one, and {..a.} bound
it. What was true is narrower — List never offered it, because an empty name
is no path segment — so the engine accepted spellings it would not advertise.
The message, the test comment and the README say that instead.
Two things the rejection finished off:
A {} token still reported "no field \"\"", pointing at a fix the loader now
rejects — two errors for one rule. It is told the name can never exist, like
an option token already is.
addressable is dead: both halves of "not empty and no dot" are now rejected
where a name is authored. Mutating it to panic leaves the suite green here
and panics on main, so it was live and is not. Keeping it would preserve the
silent-hiding this change removes — List quietly omitting a name rather than
New refusing it.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
The operand order was written out in three places; it now lives at calcVars,
which fixes it, and the other two point there. Dropped the note explaining
why ')' is not reserved, which said what the set is not rather than what it
is, and shortened reservedList's doc to less than its body. The note on held
now states where it reaches instead of arguing against a design this repo no
longer contains.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
The dedup now runs after the per-arm loop, so a missing reference path or a
missing field is reported as itself. A repeated reference arm is still
caught: the loop lets a well-formed reference through without erroring, and
the dedup reads the arms as written.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
A field the format rendered and a calc read was drawn twice, so the operand
shown could differ from the operand computed — the same disagreement the
dotted-path rule already fences, in its plainest spelling. The README
carried it as a caveat, which is what a rule like this exists to remove.
A calc operand now joins the names an expansion holds, so it is drawn once
and every later read of it — the calc, and any bare token spelling it —
sees that draw. The hold stays per expansion: each repeat iteration and each
nested template draws its own.
expand reads a calc's operands before the call and hands over their values,
so a builtin takes (emitted, operands) rather than the sibling fields, and
the evaluator indexes that slice instead of walking the node tree. That is
what keeps the draws a local. Handing them to a builtin instead lets them
escape through an indirect call, which put two maps on the heap for every
held format, calc or not: BenchmarkBound went 56 B/5 allocs -> 744 B/10.
Measured against main: Bound 359 -> 349 ns at 56 B/5 allocs, unchanged;
Calc 416 -> 577 ns and one more alloc, which is what the correlation costs.
Validation is unchanged: t.bound still carries only the levels a dotted
token reads, so the overlap fences fence exactly what they did.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
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>
lilleman
M
Mikael Göransson