first example of a map adjustment

this also includes some more monad plumbing, and an option for the
linter to actually write things out again. Some of the previous commit
was reverted a bit since it turned out to be stupid, but overall it was
suprisingly easy once I got around to it, so yay! i guess

Also includes a fairly silly example of how to use it.

1 files changed, 9 insertions, 2 deletions

diff --git a/lib/LintWriter.hs b/lib/LintWriter.hs
index 8d91948..54a5954 100644
--- a/lib/LintWriter.hs
+++ b/lib/LintWriter.hs
@@ -84,9 +84,12 @@ resultToOffers (LintResult a) = mapMaybe lintToOffer $ snd a
 resultToLints :: LintResult a -> [Lint]
 resultToLints (LintResult res) = snd res
 
--- | run a linter
+resultToAdjusted :: LintResult a -> a
+resultToAdjusted (LintResult res) = fst res
+
+-- | run a linter. Returns the adjusted context, and a list of lints
 runLintWriter :: ctxt -> Context -> LintWriter ctxt -> LintResult ctxt
-runLintWriter c c' linter =  LintResult (c, fst $ fromLinterState lints)
+runLintWriter c c' linter =  LintResult (snd $ fromLinterState lints,fst $ fromLinterState lints)
   where lints = snd $ runReader ranstate (c',c)
         ranstate = runStateT linter (LinterState ([], c))
 
@@ -104,6 +107,8 @@ dependsOn dep = tell' $ Depends dep
 offersEntrypoint :: Text -> LintWriter a
 offersEntrypoint text = tell' $ Offers text
 
+-- | adjusts the context. Gets a copy of the /current/ context, i.e. one which might
+-- have already been changed by other lints
 adjust :: (a -> a) -> LintWriter a
 adjust f = modify $ LinterState . second f . fromLinterState
 
@@ -114,6 +119,8 @@ warn = lint Warning
 forbid = lint Forbidden
 complain = lint Error
 
+
+-- | get the context as it was originally, without any modifications
 askContext :: LintWriter' a a
 askContext = lift $ asks snd