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| author | John MacFarlane <jgm@berkeley.edu> | 2018-08-10 15:13:19 -0700 |
|---|---|---|
| committer | John MacFarlane <jgm@berkeley.edu> | 2018-08-10 15:13:19 -0700 |
| commit | 7bc879268c1a86799a642280c296011e07e98c77 (patch) | |
| tree | c10f0f7e75db4222fbbfc45708271a7942944baa /src | |
| parent | e055f1b21e0c9a4486850eac3a2dea12b7d74849 (diff) | |
| download | pandoc-7bc879268c1a86799a642280c296011e07e98c77.tar.gz | |
Avoid non-exhaustive pattern match.
Diffstat (limited to 'src')
| -rw-r--r-- | src/Text/Pandoc/ImageSize.hs | 22 |
1 files changed, 12 insertions, 10 deletions
diff --git a/src/Text/Pandoc/ImageSize.hs b/src/Text/Pandoc/ImageSize.hs index c5fe98a66..00ab86eab 100644 --- a/src/Text/Pandoc/ImageSize.hs +++ b/src/Text/Pandoc/ImageSize.hs @@ -319,20 +319,22 @@ pngSize img = do (shift w1 24 + shift w2 16 + shift w3 8 + w4, shift h1 24 + shift h2 16 + shift h3 8 + h4) _ -> Nothing -- "PNG parse error" - let (dpix, dpiy) = findpHYs rest'' + (dpix, dpiy) <- findpHYs rest'' return ImageSize { pxX = x, pxY = y, dpiX = dpix, dpiY = dpiy } -findpHYs :: ByteString -> (Integer, Integer) +findpHYs :: ByteString -> Maybe (Integer, Integer) findpHYs x - | B.null x || "IDAT" `B.isPrefixOf` x = (72,72) + | B.null x || "IDAT" `B.isPrefixOf` x = return (72,72) | "pHYs" `B.isPrefixOf` x = - let [x1,x2,x3,x4,y1,y2,y3,y4,u] = - map fromIntegral $ unpack $ B.take 9 $ B.drop 4 x - factor = if u == 1 -- dots per meter - then \z -> z * 254 `div` 10000 - else const 72 - in ( factor $ shift x1 24 + shift x2 16 + shift x3 8 + x4, - factor $ shift y1 24 + shift y2 16 + shift y3 8 + y4 ) + case map fromIntegral $ unpack $ B.take 9 $ B.drop 4 x of + [x1,x2,x3,x4,y1,y2,y3,y4,u] -> do + let factor = if u == 1 -- dots per meter + then \z -> z * 254 `div` 10000 + else const 72 + return + ( factor $ shift x1 24 + shift x2 16 + shift x3 8 + x4, + factor $ shift y1 24 + shift y2 16 + shift y3 8 + y4 ) + _ -> mzero | otherwise = findpHYs $ B.drop 1 x -- read another byte gifSize :: ByteString -> Maybe ImageSize |