diff options
Diffstat (limited to 'lib/Hakyll/Core/Compiler.hs')
| -rw-r--r-- | lib/Hakyll/Core/Compiler.hs | 37 |
1 files changed, 35 insertions, 2 deletions
diff --git a/lib/Hakyll/Core/Compiler.hs b/lib/Hakyll/Core/Compiler.hs index 42b24d6..870d0af 100644 --- a/lib/Hakyll/Core/Compiler.hs +++ b/lib/Hakyll/Core/Compiler.hs @@ -24,13 +24,16 @@ module Hakyll.Core.Compiler , cached , unsafeCompiler , debugCompiler + , noResult + , withErrorMessage ) where -------------------------------------------------------------------------------- -import Control.Monad (when, unless) +import Control.Monad (unless, when, (>=>)) import Data.Binary (Binary) import Data.ByteString.Lazy (ByteString) +import qualified Data.List.NonEmpty as NonEmpty import Data.Typeable (Typeable) import System.Environment (getProgName) import System.FilePath (takeExtension) @@ -62,6 +65,7 @@ getUnderlyingExtension = takeExtension . toFilePath <$> getUnderlying -------------------------------------------------------------------------------- +-- | Create an item from the underlying identifier and a given value. makeItem :: a -> Compiler (Item a) makeItem x = do identifier <- getUnderlying @@ -141,6 +145,10 @@ saveSnapshot snapshot item = do -------------------------------------------------------------------------------- +-- | Turn on caching for a compilation value to avoid recomputing it +-- on subsequent Hakyll runs. +-- The storage key consists of the underlying identifier of the compiled +-- ressource and the given name. cached :: (Binary a, Typeable a) => String -> Compiler a @@ -177,12 +185,37 @@ cached name compiler = do -------------------------------------------------------------------------------- +-- | Run an IO computation without dependencies in a Compiler unsafeCompiler :: IO a -> Compiler a unsafeCompiler = compilerUnsafeIO -------------------------------------------------------------------------------- --- | Compiler for debugging purposes +-- | Fail so that it is treated as non-defined in an @\$if()\$@ branching +-- "Hakyll.Web.Template" macro, and alternative +-- 'Hakyll.Web.Template.Context.Context's are tried +-- +-- @since 4.13.0 +noResult :: String -> Compiler a +noResult = compilerNoResult . return + + +-------------------------------------------------------------------------------- +-- | Prepend an error line to the error, if there is one. This allows you to +-- add helpful context to error messages. +-- +-- @since 4.13.0 +withErrorMessage :: String -> Compiler a -> Compiler a +withErrorMessage x = do + compilerTry >=> either (compilerResult . CompilerError . prepend) return + where + prepend (CompilationFailure es) = CompilationFailure (x `NonEmpty.cons` es) + prepend (CompilationNoResult es) = CompilationNoResult (x : es) + + +-------------------------------------------------------------------------------- +-- | Compiler for debugging purposes. +-- Passes a message to the debug logger that is printed in verbose mode. debugCompiler :: String -> Compiler () debugCompiler msg = do logger <- compilerLogger <$> compilerAsk |