-- Hoogle documentation, generated by Haddock -- See Hoogle, http://www.haskell.org/hoogle/ -- | Source code suggestions -- -- HLint gives suggestions on how to improve your source code. @package hlint @version 2.2.2 -- | WARNING: This module represents the evolving version of the HLint -- API. It will be renamed to drop the "4" in the next major -- version. -- -- This module provides a way to apply HLint hints. If you want to just -- run hlint in-process and collect the results see -- hlint. If you want to approximate the hlint experience -- with a more structured API try: -- -- 
--   (flags, classify, hint) <- autoSettings
--   Right m <- parseModuleEx flags "MyFile.hs" Nothing
--   print $ applyHints classify hint [m]
--
module Language.Haskell.HLint4 -- | This function takes a list of command line arguments, and returns the -- given hints. To see a list of arguments type hlint --help at -- the console. This function writes to the stdout/stderr streams, unless -- --quiet is specified. -- -- As an example: -- -- 
--   do hints <- hlint ["src", "--ignore=Use map","--quiet"]
--      when (length hints > 3) $ error "Too many hints!"
--
-- -- Warning: The flags provided by HLint are relatively stable, but -- do not have the same API stability guarantees as the rest of the -- strongly-typed API. Do not run this function on your server with -- untrusted input. hlint :: [String] -> IO [Idea] -- | Given a way of classifying results, and a Hint, apply to a set -- of modules generating a list of Ideas. The Idea values -- will be ordered within a file. -- -- Given a set of modules, it may be faster to pass each to -- applyHints in a singleton list. When given multiple modules at -- once this function attempts to find hints between modules, which is -- slower and often pointless (by default HLint passes modules -- singularly, using --cross to pass all modules together). applyHints :: [Classify] -> Hint -> [ModuleEx] -> [Idea] -- | An idea suggest by a Hint. data Idea Idea :: [String] -> [String] -> Severity -> String -> SrcSpan -> String -> Maybe String -> [Note] -> [Refactoring SrcSpan] -> Idea -- | The modules the idea is for, usually a singleton. [ideaModule] :: Idea -> [String] -- | The declarations the idea is for, usually a singleton, typically the -- function name, but may be a type name. [ideaDecl] :: Idea -> [String] -- | The severity of the idea, e.g. Warning. [ideaSeverity] :: Idea -> Severity -- | The name of the hint that generated the idea, e.g. "Use -- reverse". [ideaHint] :: Idea -> String -- | The source code the idea relates to. [ideaSpan] :: Idea -> SrcSpan -- | The contents of the source code the idea relates to. [ideaFrom] :: Idea -> String -- | The suggested replacement, or Nothing for no replacement (e.g. -- on parse errors). [ideaTo] :: Idea -> Maybe String -- | Notes about the effect of applying the replacement. [ideaNote] :: Idea -> [Note] -- | How to perform this idea [ideaRefactoring] :: Idea -> [Refactoring SrcSpan] -- | How severe an issue is. data Severity -- | The issue has been explicitly ignored and will usually be hidden (pass -- --show on the command line to see ignored ideas). Ignore :: Severity -- | Suggestions are things that some people may consider improvements, but -- some may not. Suggestion :: Severity -- | Warnings are suggestions that are nearly always a good idea to apply. Warning :: Severity -- | Available as a setting for the user. Error :: Severity -- | A note describing the impact of the replacement. data Note -- | The replacement is increases laziness, for example replacing -- reverse (reverse x) with x makes the code lazier. IncreasesLaziness :: Note -- | The replacement is decreases laziness, for example replacing (fst -- x, snd x) with x makes the code stricter. DecreasesLaziness :: Note -- | The replacement removes errors, for example replacing foldr1 -- (+) with sum removes an error on [], and might -- contain the text "on []". RemovesError :: String -> Note -- | The replacement assumes standard type class lemmas, a hint with the -- note ValidInstance "Eq" "x" might only be valid if the -- x variable has a reflexive Eq instance. ValidInstance :: String -> String -> Note -- | The replacement requires this extension to be available. RequiresExtension :: String -> Note -- | An arbitrary note. Note :: String -> Note -- | How to classify an Idea. If any matching field is "" -- then it matches everything. data Classify Classify :: Severity -> String -> String -> String -> Classify -- | Severity to set the Idea to. [classifySeverity] :: Classify -> Severity -- | Match on Idea field ideaHint. [classifyHint] :: Classify -> String -- | Match on Idea field ideaModule. [classifyModule] :: Classify -> String -- | Match on Idea field ideaDecl. [classifyDecl] :: Classify -> String -- | Get the Cabal configured data directory of HLint. getHLintDataDir :: IO FilePath -- | The function produces a tuple containg ParseFlags (for -- parseModuleEx), and Classify and Hint for -- applyHints. It approximates the normal HLint configuration -- steps, roughly: -- --
    --
  1. Use findSettings with readSettingsFile to find and -- load the HLint settings files.
    2. --
  2. Use parseFlagsAddFixities and resolveHints to -- transform the outputs of findSettings.
    3. --
-- -- If you want to do anything custom (e.g. using a different data -- directory, storing intermediate outputs, loading hints from a -- database) you are expected to copy and paste this function, then -- change it to your needs. autoSettings :: IO (ParseFlags, [Classify], Hint) -- | A version of autoSettings which respects some of the arguments -- supported by HLint. If arguments unrecognised by HLint are used it -- will result in an error. Arguments which have no representation in the -- return type are silently ignored. argsSettings :: [String] -> IO (ParseFlags, [Classify], Hint) -- | Given a function to load a module (typically readSettingsFile), -- and a module to start from (defaults to hlint.yaml) find the -- information from all settings files. findSettings :: (String -> IO (FilePath, Maybe String)) -> Maybe String -> IO ([Fixity], [Classify], Hint) -- | Given a directory (or Nothing to imply getHLintDataDir), -- and a module name (e.g. HLint.Default), find the settings -- file associated with it, returning the name of the file, and -- (optionally) the contents. -- -- This function looks for all settings files starting with -- HLint. in the directory argument, and all other files -- relative to the current directory. readSettingsFile :: Maybe FilePath -> String -> IO (FilePath, Maybe String) -- | Functions to generate hints, combined using the Monoid -- instance. data Hint -- | The identity function. In previous versions of HLint this function was -- useful. Now, it isn't. resolveHints :: Hint -> Hint -- | Result of parseModuleEx, representing a parsed module. data ModuleEx -- | Parse a Haskell module. Applies the C pre processor, and uses -- best-guess fixity resolution if there are ambiguities. The filename -- - is treated as stdin. Requires some flags (often -- defaultParseFlags), the filename, and optionally the contents -- of that file. This version uses both hs-src-exts AND ghc-lib. parseModuleEx :: ParseFlags -> FilePath -> Maybe String -> IO (Either ParseError ModuleEx) -- | Create a ModuleEx from GHC annotations and module tree. Note -- that any hints that work on the haskell-src-exts won't work. createModuleEx :: ApiAnns -> Located (HsModule GhcPs) -> ModuleEx -- | Default value for ParseFlags. defaultParseFlags :: ParseFlags -- | Given some fixities, add them to the existing fixities in -- ParseFlags. parseFlagsAddFixities :: [Fixity] -> ParseFlags -> ParseFlags -- | A parse error. data ParseError ParseError :: SrcLoc -> String -> String -> ParseError -- | Location of the error. [parseErrorLocation] :: ParseError -> SrcLoc -- | Message about the cause of the error. [parseErrorMessage] :: ParseError -> String -- | Snippet of several lines (typically 5) including a > -- character pointing at the faulty line. [parseErrorContents] :: ParseError -> String -- | Created with defaultParseFlags, used by parseModuleEx. data ParseFlags ParseFlags :: CppFlags -> ParseMode -> ParseFlags -- | How the file is preprocessed (defaults to NoCpp). [cppFlags] :: ParseFlags -> CppFlags -- | How the file is parsed (defaults to all fixities in the base -- package and most non-conflicting extensions). [hseFlags] :: ParseFlags -> ParseMode -- | What C pre processor should be used. data CppFlags -- | No pre processing is done. NoCpp :: CppFlags -- | Lines prefixed with # are stripped. CppSimple :: CppFlags -- | The cpphs library is used. Cpphs :: CpphsOptions -> CppFlags -- | A reexport of Language.Haskell.HLint4 for compatibility -- purposes. module Language.Haskell.HLint3 -- | WARNING: This module represents the old version of the HLint -- API. It will be deleted in favour of -- Language.Haskell.HLint3 in the next major version. -- -- This module provides a library interface to HLint, strongly modelled -- on the command line interface. module Language.Haskell.HLint -- | This function takes a list of command line arguments, and returns the -- given suggestions. To see a list of arguments type hlint -- --help at the console. This function writes to the stdout/stderr -- streams, unless --quiet is specified. -- -- As an example: -- -- 
--   do hints <- hlint ["src", "--ignore=Use map","--quiet"]
--      when (length hints > 3) $ error "Too many hints!"
--
hlint :: [String] -> IO [Suggestion] -- | A suggestion - the Show instance is of particular use. data Suggestion -- | From a suggestion, extract the file location it refers to. suggestionLocation :: Suggestion -> SrcLoc -- | From a suggestion, determine how severe it is. suggestionSeverity :: Suggestion -> Severity -- | How severe an issue is. data Severity -- | The issue has been explicitly ignored and will usually be hidden (pass -- --show on the command line to see ignored ideas). Ignore :: Severity -- | Suggestions are things that some people may consider improvements, but -- some may not. Suggestion :: Severity -- | Warnings are suggestions that are nearly always a good idea to apply. Warning :: Severity -- | Available as a setting for the user. Error :: Severity instance GHC.Classes.Ord Language.Haskell.HLint.Suggestion instance GHC.Classes.Eq Language.Haskell.HLint.Suggestion instance GHC.Show.Show Language.Haskell.HLint.Suggestion