claude@clouddev1
7dfa718c6e
The old humanise() fell back to chumsky's terse Display for non-
custom errors and appended "(near `X`)", which on top of an
already-cryptic "found 'i' expected ':'" turned the message into
a puzzle. Now humanise() reads the structured RichReason, lists
expected RichPatterns in plain prose, and prefixes the message
with the consumed context.
Before: parse error: found 'i' expected ':' (near `i`)
After: parse error: after `change column Rich`, expected `:`,
found `i`
dispatch_dsl additionally echoes the source line on parse failure
(matching the success path's "running: ...") and prints a `^` caret
under the failure position, so the user can see what got submitted
and where the parser broke without re-reading from scratch.
Known limit: keyword_ci's custom-error mismatches don't aggregate
across choice alternatives, so messages like "expected DATA or
TABLE" (bison-equivalent) aren't yet possible. That's a structural
fix to the keyword matcher, deferred to a future parser-affordances
ADR.
Tests: +2 structural-error regression tests.