30 lines
1.3 KiB
Text
30 lines
1.3 KiB
Text
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Spent today bulding the Evil Splicer, a program that parses `ghc -ddump-splices`
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output, and uses it to expand Template Haskell splices in source code.
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I hope to use this crazy hack to get the webapp working on Android.
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This was a good opportunity to use the
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[Parsec](http://hackage.haskell.org/package/parsec) library for parsing the
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ghc output. I've never really used it before, but found it quite nice to
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work with. The learning curve, if you already know monads and applicatives,
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is about 5 minutes. And instead of ugly regular expressions, you can work
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with nice code that's easily composable and refactorable. Even the ugly
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bits come out well:
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[[!format haskell """
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{- All lines of the splice result will start with the same
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- indent, which is stripped. Any other indentation is preserved. -}
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i <- lookAhead indent
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result <- unlines <$> many1 (string i >> restOfLine)
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"""]]
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Anyway, it works.. sorta. The parser works great! The splices that ghc
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outputs are put into the right places in the source files, and formatted in
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a way that ghc is able to build. Often though, they contain code that
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doesn't actually build as-is. I'm working to fix up the code to get closer
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to buildable.
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----
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Meanwhile, guilhem has made ssh connection caching work for rsync special
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remotes! It's very nice to have another developer working on git-annex. :)
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