[Haskell-cafe] propogation of Error

[brad clawsie]

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hi. i have a partial library for parsing ogg files here:

http://hpaste.org/12705

i have a question about an aspect of the code. in the function 

checkHeader

there are a sequence of functions to check various elements in the
header of a ogg file. if i test this function against a file that
*isn't* an ogg file, i.e.

badFile = "/home/user/.bashrc" :: String
main = parseOgg badFile >>= (\x -> print x)

i would expect to get back the Error from the *first* function in the
sequence of functions in checkHeader (oggHeaderError from the oggHeader
function). but instead i always see the Error from the *last* function
in the sequence, OggPacketFlagError from the OggPacketFlag function. why
is this? is there any way i can get the desired behavior...i.e. see the
Error from the first function in the sequence that fails?

thanks
brad
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