221 lines
8.1 KiB
Haskell
221 lines
8.1 KiB
Haskell
{-# LANGUAGE LambdaCase #-}
|
|
{-# LANGUAGE NoImplicitPrelude #-}
|
|
|
|
module Language.Haskell.Brittany.Internal.Layouters.Pattern where
|
|
|
|
import qualified Data.Foldable as Foldable
|
|
import qualified Data.Sequence as Seq
|
|
import qualified Data.Text as Text
|
|
import GHC (GenLocated(L), ol_val)
|
|
import GHC.Hs
|
|
import qualified GHC.OldList as List
|
|
import GHC.Types.Basic
|
|
import Language.Haskell.Brittany.Internal.LayouterBasics
|
|
import {-# SOURCE #-} Language.Haskell.Brittany.Internal.Layouters.Expr
|
|
import Language.Haskell.Brittany.Internal.Layouters.Type
|
|
import Language.Haskell.Brittany.Internal.Prelude
|
|
import Language.Haskell.Brittany.Internal.PreludeUtils
|
|
import Language.Haskell.Brittany.Internal.Types
|
|
|
|
|
|
|
|
-- | layouts patterns (inside function bindings, case alternatives, let
|
|
-- bindings or do notation). E.g. for input
|
|
-- > case computation of
|
|
-- > (warnings, Success a b) -> ..
|
|
-- This part ^^^^^^^^^^^^^^^^^^^^^^^ of the syntax tree is layouted by
|
|
-- 'layoutPat'. Similarly for
|
|
-- > func abc True 0 = []
|
|
-- ^^^^^^^^^^ this part
|
|
-- We will use `case .. of` as the imagined prefix to the examples used in
|
|
-- the different cases below.
|
|
layoutPat :: LPat GhcPs -> ToBriDocM (Seq BriDocNumbered)
|
|
layoutPat lpat@(L _ pat) = docWrapNode lpat $ case pat of
|
|
WildPat _ -> fmap Seq.singleton $ docLit $ Text.pack "_"
|
|
-- _ -> expr
|
|
VarPat _ n ->
|
|
fmap Seq.singleton $ docLit $ lrdrNameToText n
|
|
-- abc -> expr
|
|
LitPat _ lit ->
|
|
fmap Seq.singleton $ allocateNode $ litBriDoc lit
|
|
-- 0 -> expr
|
|
ParPat _ inner -> do
|
|
-- (nestedpat) -> expr
|
|
left <- docLit $ Text.pack "("
|
|
right <- docLit $ Text.pack ")"
|
|
innerDocs <- colsWrapPat =<< layoutPat inner
|
|
return $ Seq.empty Seq.|> left Seq.|> innerDocs Seq.|> right
|
|
-- return $ (left Seq.<| innerDocs) Seq.|> right
|
|
-- case Seq.viewl innerDocs of
|
|
-- Seq.EmptyL -> fmap return $ docLit $ Text.pack "()" -- this should never occur..
|
|
-- x1 Seq.:< rest -> case Seq.viewr rest of
|
|
-- Seq.EmptyR ->
|
|
-- fmap return $ docSeq
|
|
-- [ docLit $ Text.pack "("
|
|
-- , return x1
|
|
-- , docLit $ Text.pack ")"
|
|
-- ]
|
|
-- middle Seq.:> xN -> do
|
|
-- x1' <- docSeq [docLit $ Text.pack "(", return x1]
|
|
-- xN' <- docSeq [return xN, docLit $ Text.pack ")"]
|
|
-- return $ (x1' Seq.<| middle) Seq.|> xN'
|
|
ConPat _ lname (PrefixCon args) -> do
|
|
-- Abc a b c -> expr
|
|
nameDoc <- lrdrNameToTextAnn lname
|
|
argDocs <- layoutPat `mapM` args
|
|
if null argDocs
|
|
then return <$> docLit nameDoc
|
|
else do
|
|
x1 <- appSep (docLit nameDoc)
|
|
xR <- fmap Seq.fromList
|
|
$ sequence
|
|
$ spacifyDocs
|
|
$ fmap colsWrapPat argDocs
|
|
return $ x1 Seq.<| xR
|
|
ConPat _ lname (InfixCon left right) -> do
|
|
-- a :< b -> expr
|
|
nameDoc <- lrdrNameToTextAnn lname
|
|
leftDoc <- appSep . colsWrapPat =<< layoutPat left
|
|
rightDoc <- colsWrapPat =<< layoutPat right
|
|
middle <- appSep $ docLit nameDoc
|
|
return $ Seq.empty Seq.|> leftDoc Seq.|> middle Seq.|> rightDoc
|
|
ConPat _ lname (RecCon (HsRecFields [] Nothing)) -> do
|
|
-- Abc{} -> expr
|
|
let t = lrdrNameToText lname
|
|
fmap Seq.singleton $ docLit $ t <> Text.pack "{}"
|
|
ConPat _ lname (RecCon (HsRecFields fs@(_:_) Nothing)) -> do
|
|
-- Abc { a = locA, b = locB, c = locC } -> expr1
|
|
-- Abc { a, b, c } -> expr2
|
|
let t = lrdrNameToText lname
|
|
fds <- fs `forM` \(L _ (HsRecField (L _ fieldOcc) fPat pun)) -> do
|
|
let FieldOcc _ lnameF = fieldOcc
|
|
fExpDoc <- if pun
|
|
then return Nothing
|
|
else Just <$> docSharedWrapper layoutPat fPat
|
|
return (lrdrNameToText lnameF, fExpDoc)
|
|
Seq.singleton <$> docSeq
|
|
[ appSep $ docLit t
|
|
, appSep $ docLit $ Text.pack "{"
|
|
, docSeq $ List.intersperse docCommaSep
|
|
$ fds <&> \case
|
|
(fieldName, Just fieldDoc) -> docSeq
|
|
[ appSep $ docLit fieldName
|
|
, appSep $ docLit $ Text.pack "="
|
|
, fieldDoc >>= colsWrapPat
|
|
]
|
|
(fieldName, Nothing) -> docLit fieldName
|
|
, docSeparator
|
|
, docLit $ Text.pack "}"
|
|
]
|
|
ConPat _ lname (RecCon (HsRecFields [] (Just (L _ 0)))) -> do
|
|
-- Abc { .. } -> expr
|
|
let t = lrdrNameToText lname
|
|
Seq.singleton <$> docSeq
|
|
[ appSep $ docLit t
|
|
, docLit $ Text.pack "{..}"
|
|
]
|
|
ConPat _ lname (RecCon (HsRecFields fs@(_:_) (Just (L _ dotdoti)))) | dotdoti == length fs -> do
|
|
-- Abc { a = locA, .. }
|
|
let t = lrdrNameToText lname
|
|
fds <- fs `forM` \(L _ (HsRecField (L _ fieldOcc) fPat pun)) -> do
|
|
let FieldOcc _ lnameF = fieldOcc
|
|
fExpDoc <- if pun
|
|
then return Nothing
|
|
else Just <$> docSharedWrapper layoutPat fPat
|
|
return (lrdrNameToText lnameF, fExpDoc)
|
|
Seq.singleton <$> docSeq
|
|
[ appSep $ docLit t
|
|
, appSep $ docLit $ Text.pack "{"
|
|
, docSeq $ fds >>= \case
|
|
(fieldName, Just fieldDoc) ->
|
|
[ appSep $ docLit fieldName
|
|
, appSep $ docLit $ Text.pack "="
|
|
, fieldDoc >>= colsWrapPat
|
|
, docCommaSep
|
|
]
|
|
(fieldName, Nothing) -> [docLit fieldName, docCommaSep]
|
|
, docLit $ Text.pack "..}"
|
|
]
|
|
TuplePat _ args boxity -> do
|
|
-- (nestedpat1, nestedpat2, nestedpat3) -> expr
|
|
-- (#nestedpat1, nestedpat2, nestedpat3#) -> expr
|
|
case boxity of
|
|
Boxed -> wrapPatListy args "()" docParenL docParenR
|
|
Unboxed -> wrapPatListy args "(##)" docParenHashLSep docParenHashRSep
|
|
AsPat _ asName asPat -> do
|
|
-- bind@nestedpat -> expr
|
|
wrapPatPrepend asPat (docLit $ lrdrNameToText asName <> Text.pack "@")
|
|
SigPat _ pat1 (HsPS _ ty1) -> do
|
|
-- i :: Int -> expr
|
|
patDocs <- layoutPat pat1
|
|
tyDoc <- docSharedWrapper layoutType ty1
|
|
case Seq.viewr patDocs of
|
|
Seq.EmptyR -> error "cannot happen ljoiuxoasdcoviuasd"
|
|
xR Seq.:> xN -> do
|
|
xN' <- -- at the moment, we don't support splitting patterns into
|
|
-- multiple lines. but we cannot enforce pasting everything
|
|
-- into one line either, because the type signature will ignore
|
|
-- this if we overflow sufficiently.
|
|
-- In order to prevent syntactically invalid results in such
|
|
-- cases, we need the AddBaseY here.
|
|
-- This can all change when patterns get multiline support.
|
|
docAddBaseY BrIndentRegular $ docSeq
|
|
[ appSep $ return xN
|
|
, appSep $ docLit $ Text.pack "::"
|
|
, docForceSingleline tyDoc
|
|
]
|
|
return $ xR Seq.|> xN'
|
|
ListPat _ elems ->
|
|
-- [] -> expr1
|
|
-- [nestedpat1, nestedpat2, nestedpat3] -> expr2
|
|
wrapPatListy elems "[]" docBracketL docBracketR
|
|
BangPat _ pat1 -> do
|
|
-- !nestedpat -> expr
|
|
wrapPatPrepend pat1 (docLit $ Text.pack "!")
|
|
LazyPat _ pat1 -> do
|
|
-- ~nestedpat -> expr
|
|
wrapPatPrepend pat1 (docLit $ Text.pack "~")
|
|
NPat _ llit@(L _ ol) mNegative _ -> do
|
|
-- -13 -> expr
|
|
litDoc <- docWrapNode llit $ allocateNode $ overLitValBriDoc $ GHC.ol_val ol
|
|
negDoc <- docLit $ Text.pack "-"
|
|
pure $ case mNegative of
|
|
Just{} -> Seq.fromList [negDoc, litDoc]
|
|
Nothing -> Seq.singleton litDoc
|
|
|
|
_ -> return <$> briDocByExactInlineOnly "some unknown pattern" lpat
|
|
|
|
colsWrapPat :: Seq BriDocNumbered -> ToBriDocM BriDocNumbered
|
|
colsWrapPat = docCols ColPatterns . fmap return . Foldable.toList
|
|
|
|
wrapPatPrepend
|
|
:: LPat GhcPs
|
|
-> ToBriDocM BriDocNumbered
|
|
-> ToBriDocM (Seq BriDocNumbered)
|
|
wrapPatPrepend pat prepElem = do
|
|
patDocs <- layoutPat pat
|
|
case Seq.viewl patDocs of
|
|
Seq.EmptyL -> return Seq.empty
|
|
x1 Seq.:< xR -> do
|
|
x1' <- docSeq [prepElem, return x1]
|
|
return $ x1' Seq.<| xR
|
|
|
|
wrapPatListy
|
|
:: [LPat GhcPs]
|
|
-> String
|
|
-> ToBriDocM BriDocNumbered
|
|
-> ToBriDocM BriDocNumbered
|
|
-> ToBriDocM (Seq BriDocNumbered)
|
|
wrapPatListy elems both start end = do
|
|
elemDocs <- Seq.fromList elems `forM` (layoutPat >=> colsWrapPat)
|
|
case Seq.viewl elemDocs of
|
|
Seq.EmptyL -> fmap Seq.singleton $ docLit $ Text.pack both
|
|
x1 Seq.:< rest -> do
|
|
sDoc <- start
|
|
eDoc <- end
|
|
rest' <- rest `forM` \bd -> docSeq
|
|
[ docCommaSep
|
|
, return bd
|
|
]
|
|
return $ (sDoc Seq.<| x1 Seq.<| rest') Seq.|> eDoc
|