• Duncan Coutts's avatar
    Make all command line flags and flag collection types monoids · 1352ee0b
    Duncan Coutts authored
    And specify command flags in a way that allows converting from or two strings.
    So not only can we parse command lines into the various flag types, we can
    convert back. This is crucial in cabal-install so that we can call Setup.hs
    scripts with all the various args, and override certain flags in a typed way
    rather than just representing them all as strings.