diff options
Diffstat (limited to 'src/Hakyll/Core/Identifier/Pattern.hs')
-rw-r--r-- | src/Hakyll/Core/Identifier/Pattern.hs | 26 |
1 files changed, 24 insertions, 2 deletions
diff --git a/src/Hakyll/Core/Identifier/Pattern.hs b/src/Hakyll/Core/Identifier/Pattern.hs index b5f01e5..0590387 100644 --- a/src/Hakyll/Core/Identifier/Pattern.hs +++ b/src/Hakyll/Core/Identifier/Pattern.hs @@ -34,11 +34,14 @@ module Hakyll.Core.Identifier.Pattern , match , doesMatch , matches + , fromCapture + , fromCaptures ) where import Data.List (intercalate) import Control.Monad (msum) import Data.Maybe (isJust) +import Data.Monoid (mempty, mappend) import GHC.Exts (IsString, fromString) @@ -78,8 +81,8 @@ parsePattern = Pattern . map toPattern . unIdentifier . parseIdentifier -- | Match an identifier against a pattern, generating a list of captures -- -match :: Pattern -> Identifier -> Maybe [[String]] -match (Pattern p) (Identifier i) = match' p i +match :: Pattern -> Identifier -> Maybe [Identifier] +match (Pattern p) (Identifier i) = fmap (map Identifier) $ match' p i -- | Check if an identifier matches a pattern -- @@ -115,3 +118,22 @@ match' (m : ms) (s : ss) = case m of CaptureMany -> let take' (i, t) = fmap (i :) $ match' ms t in msum $ map take' $ splits (s : ss) + +-- | Create an identifier from a pattern by filling in the captures with a given +-- string +-- +fromCapture :: Pattern -> Identifier -> Identifier +fromCapture pattern = fromCaptures pattern . repeat + +-- | Create an identifier from a pattern by filling in the captures with the +-- given list of strings +-- +fromCaptures :: Pattern -> [Identifier] -> Identifier +fromCaptures (Pattern []) _ = mempty +fromCaptures (Pattern (m : ms)) [] = case m of + Literal l -> Identifier [l] `mappend` fromCaptures (Pattern ms) [] + _ -> error $ "Hakyll.Core.Identifier.Pattern.fromCaptures: " + ++ "identifier list exhausted" +fromCaptures (Pattern (m : ms)) ids@(i : is) = case m of + Literal l -> Identifier [l] `mappend` fromCaptures (Pattern ms) ids + _ -> i `mappend` fromCaptures (Pattern ms) is |