`build_formula` took the target's raw span, so `|Total Revenue| = ...`
parsed to `Formula { target: "|Total Revenue|" }` — delimiters included —
while an `Expr::Ref` for the same name came back unquoted. The target
names a `_Measure` item, so `Model::add_formula` created an item named
literally `|Total Revenue|`: the formula wrote into a ghost column, the
user's own `Total Revenue` item stayed empty, and nothing referring to
the target by name resolved.
Both user-facing entry points hit this: the TUI formula minibuffer
(ui/effect.rs AddFormula) and `.improv` load (persistence/parse.rs).
No caller relied on the raw span — the writer emits `Formula::raw`, so
file round-tripping is unaffected, and the `_Measure` exclusion set in
persistence/format.rs now matches the real item instead of the ghost.
Fixed in improvise-formula rather than at the three call sites: the
target and a reference are the same syntactic identifier, so unquoting
them differently is the defect itself, and three copies of unquote_pipe
would be three chances to drift.
The grammar comment that documented the raw span is updated, and the two
tests that asserted the pipes (parser.rs, improvise-gp) now assert the
semantic round trip.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01EoW5BB87ZZdm96SvBTWawH
Edward Langley
2b1ca2e4c4