api_suggest carried ~80 lines of ranking policy — the exactness-boosted
scoring, local/upstream blending with dedupe, and the token-respelling
correction loop — all consuming the match: prefix/fuzzy vocabulary that
places.py produces. Producer and consumer now live together:
places.suggest(q, upstream, limit) implements the whole policy with the
upstream geocoder lookup injected as a callable, so places stays free of
the fetch layer and the policy is testable without FastAPI.
The endpoint is the HTTP shim: call places.suggest, map the
nothing-at-all-to-serve failure to a 502. Behavior unchanged.
Policy tests: upstream skipped when the local answer convinces, blend +
dedupe, the exactness boost (a hamlet spelled like the typo can't beat
Seattle), single-typo queries answered by the fuzzy matcher without a
correction, the correction path verified via the upstream probe,
upstream failure degrading to local results, and the terminal
error-propagation case.
Add /api/v2/suggest and wire the location picker's search box to it as a
debounced type-ahead: top-5 place suggestions that tolerate a single-letter
typo (substituted, missing, or extra letter, or two adjacent letters swapped)
anywhere in the query, including the first character.
- backend/places.py: local place index built from a GeoNames cities dump
(downloaded once into data/geonames/, loaded in a background thread; the
app boots and serves without it). Exact-prefix matches rank first by
population, then names one edit away; a token vocabulary respells one
mistyped word against known place-name tokens ("pest seattle" ->
"west seattle") for retry against the upstream geocoder, which covers
neighbourhood-level places the dump lacks. THERMOGRAPH_CITIES picks the
dump (default cities1000).
- /suggest blends local and upstream results by population with an exactness
boost, so "Seatle" (a Cumbrian hamlet) can't outrank Seattle when the
query is one edit from the city, while "munchen" still surfaces Munich via
upstream (the index only knows English names). Upstream lookups are
memoized and skipped entirely when the index answers convincingly.
- mappicker.js: debounced (250ms) live suggestions with abort + sequence
guards against stale responses, arrow-key navigation, Enter-picks-highlight,
Escape dismissing the list before closing the overlay. Submit goes through
the same typo-tolerant endpoint.
- climate.geocode results now carry population (used for ranking).
