--- Mapping from thing (e.g. "Cabal") to version (e.g. "1.10.0.0")
-type ThingVersionMap = [(String, String)]
-
-addThingVersion :: ThingVersionMap -> String -> String -> Maybe ThingVersionMap
-addThingVersion mapping thing version
- = case lookup thing mapping of
- Just version' ->
- if version == version'
- then Just mapping
- else Nothing
- Nothing ->
- Just ((thing, version) : mapping)
-