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Method import strategies (Brightway's term for imperative CF-mutation functions applied at import time) are stateful and non-idempotent: they mutate a persisted store, so re-running an import re-applies the mutation. VoLCA parses methods fresh from source on every load, so the same adjustment can be expressed as data instead: a `[[methods.patches]]` TOML block that rescales or overrides matched characterization factors, applied as a pure transform right after parsing. A patch selector (category, flow name/prefix, CAS, subcompartment substring) is a product type with conjunctive matching; the decoder rejects an empty selector and requires exactly one of `scale` or `set-value`, so invalid patches are unrepresentable rather than silently ambiguous. A patch that matches zero characterization factors logs a warning at load time instead of failing silently. Config.mcPatches defaults to `[]`, so existing configs are unaffected.
The per-activity /impacts endpoint already let a caller drop delayed
long-term emissions before scoring; the bulk multi-activity endpoint
(POST /db/{db}/impacts/{collection}) didn't, forcing scripts that need
both a full panel and long-term exclusion onto the much slower
per-activity path. Threads the same LongTermMode through
batchImpactsH/runBatchImpacts, applied to each solved inventory before
characterization. Also exposed on the score_activities MCP tool, which
had the same gap relative to score_activity.
mapAccumL instead of a foldl with quadratic list append, maybeToList instead of a local reimplementation, and a total factorValues helper in the spec instead of irrefutable let patterns that would crash rather than fail cleanly.
Also record the bulk exclude-long-term extension in the changelog.
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Summary
[[methods.patches]]: a declarative, idempotent way to rescale or override matched characterization factors at method-load time — the data-driven equivalent of a Brightway import strategy, without its statefulness (re-loading never compounds a patch, since it's re-derived from the untouched source file every time).exclude-long-termto the bulkPOST /impactsendpoint and thescore_activitiesMCP tool, which previously only supported it per-activity.Test plan
cabal build lib:volca— clean, no warningscabal test lca-tests— 1543 examples, 0 failures[[methods.patches]]block loads without a "touched 0 CFs" warning; a deliberately wrong selector does trigger the warning