48 lines
1.2 KiB
Haskell
48 lines
1.2 KiB
Haskell
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-- | An identifier is a type used to uniquely identify a resource, target...
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--
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-- One can think of an identifier as something similar to a file path. An
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-- identifier is a path as well, with the different elements in the path
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-- separated by @/@ characters. Examples of identifiers are:
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--
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-- * @posts/foo.markdown@
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--
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-- * @index@
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--
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-- * @error/404@
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--
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module Hakyll.Core.Identifier
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( Identifier (..)
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, parseIdentifier
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, toFilePath
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) where
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import Control.Arrow (second)
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import GHC.Exts (IsString, fromString)
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import System.FilePath (joinPath)
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-- | An identifier used to uniquely identify a value
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--
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newtype Identifier = Identifier {unIdentifier :: [String]}
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deriving (Eq, Ord)
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instance Show Identifier where
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show = toFilePath
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instance IsString Identifier where
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fromString = parseIdentifier
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-- | Parse an identifier from a string
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--
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parseIdentifier :: String -> Identifier
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parseIdentifier = Identifier . filter (not . null) . split'
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where
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split' [] = [[]]
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split' str = let (pre, post) = second (drop 1) $ break (== '/') str
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in pre : split' post
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-- | Convert an identifier to a relative 'FilePath'
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--
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toFilePath :: Identifier -> FilePath
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toFilePath = joinPath . unIdentifier
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