forked from GitHub/gf-core
20 lines
523 B
Haskell
20 lines
523 B
Haskell
import Data.List (intersperse)
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import Data.Char (isAlpha)
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-- to massage cf rules to funs, in order, preserving comments
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-- to get cats, use pg -printer=gf
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cf2gf :: FilePath -> IO ()
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cf2gf file = do
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ss <- readFile file >>= return . lines
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mapM_ (putStrLn . mkOne) ss
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mkOne line = case words line of
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fun : cat : "::=" : cats ->
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let
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(cats0,cats2) = span (/=";") cats
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cats1 = filter (isAlpha . head) cats0 ++ [cat]
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in
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unwords $ [init fun, ":"] ++ intersperse "->" cats1 ++ cats2
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_ -> line
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