From 8c30a41ab97ac127ea0ba98e23540f7790f6dbfb Mon Sep 17 00:00:00 2001 From: gnusosa@2538fbd05a723a8f83b066e159f5d5f83b9f400d Date: Wed, 24 Feb 2016 20:19:17 +0000 Subject: --- doc/forum/Understanding_changesFile_equation.mdwn | 15 +++++++++++++++ 1 file changed, 15 insertions(+) create mode 100644 doc/forum/Understanding_changesFile_equation.mdwn (limited to 'doc/forum/Understanding_changesFile_equation.mdwn') diff --git a/doc/forum/Understanding_changesFile_equation.mdwn b/doc/forum/Understanding_changesFile_equation.mdwn new file mode 100644 index 00000000..5e360097 --- /dev/null +++ b/doc/forum/Understanding_changesFile_equation.mdwn @@ -0,0 +1,15 @@ +Hi, I'm trying to understand a part of the `changesFile` equation, specifically `oldstat`. + +``` +changesFile :: Checkable p i => p i -> FilePath -> Property i +changesFile p f = checkResult getstat comparestat p + where + getstat = catchMaybeIO $ getSymbolicLinkStatus f + comparestat oldstat = do + newstat <- getstat + return $ if samestat oldstat newstat then NoChange else MadeChange +``` + +As we see, we catch `getstat` given `f`, but what I don't understand or see, is how is `oldstat` been passed/generated? + +Thanks for the help. -- cgit v1.2.3