{-# LANGUAGE FlexibleContexts #-}
{-# LANGUAGE GADTs #-}
{-# LANGUAGE LambdaCase #-}
{-# LANGUAGE OverloadedStrings #-}

-- | Printing combinators. The definitions here are presented in such an
-- order so you can just go through the Haddocks and by the end of the file
-- you should have a pretty good idea how to program rendering logic.
module Ormolu.Printer.Combinators
  ( -- * The 'R' monad
    R,
    runR,
    getAnns,
    getEnclosingSpan,

    -- * Combinators

    -- ** Basic
    txt,
    atom,
    space,
    newline,
    inci,
    located,
    located',
    switchLayout,
    Layout (..),
    vlayout,
    getLayout,
    breakpoint,
    breakpoint',

    -- ** Formatting lists
    sep,
    sepSemi,
    canUseBraces,
    useBraces,
    dontUseBraces,

    -- ** Wrapping
    BracketStyle (..),
    sitcc,
    backticks,
    banana,
    braces,
    brackets,
    parens,
    parensHash,
    pragmaBraces,
    pragma,

    -- ** Literals
    comma,
    equals,

    -- ** Stateful markers
    SpanMark (..),
    spanMarkSpan,
    HaddockStyle (..),
    setSpanMark,
    getSpanMark,
  )
where

import Control.Monad
import Data.List (intersperse)
import Data.Text (Text)
import Ormolu.Printer.Comments
import Ormolu.Printer.Internal
import SrcLoc

----------------------------------------------------------------------------
-- Basic

-- | Enter a 'Located' entity. This combinator handles outputting comments
-- and sets layout (single-line vs multi-line) for the inner computation.
-- Roughly, the rule for using 'located' is that every time there is a
-- 'Located' wrapper, it should be “discharged” with a corresponding
-- 'located' invocation.
located ::
  -- | Thing to enter
  Located a ->
  -- | How to render inner value
  (a -> R ()) ->
  R ()
located :: Located a -> (a -> R ()) -> R ()
located (L (UnhelpfulSpan FastString
_) a
a) a -> R ()
f = a -> R ()
f a
a
located (L (RealSrcSpan RealSrcSpan
l) a
a) a -> R ()
f = do
  RealSrcSpan -> R ()
spitPrecedingComments RealSrcSpan
l
  RealSrcSpan -> R () -> R ()
withEnclosingSpan RealSrcSpan
l (R () -> R ()) -> R () -> R ()
forall a b. (a -> b) -> a -> b
$
    [SrcSpan] -> R () -> R ()
switchLayout [RealSrcSpan -> SrcSpan
RealSrcSpan RealSrcSpan
l] (a -> R ()
f a
a)
  RealSrcSpan -> R ()
spitFollowingComments RealSrcSpan
l

-- | A version of 'located' with arguments flipped.
located' ::
  -- | How to render inner value
  (a -> R ()) ->
  -- | Thing to enter
  Located a ->
  R ()
located' :: (a -> R ()) -> Located a -> R ()
located' = (Located a -> (a -> R ()) -> R ())
-> (a -> R ()) -> Located a -> R ()
forall a b c. (a -> b -> c) -> b -> a -> c
flip Located a -> (a -> R ()) -> R ()
forall a. Located a -> (a -> R ()) -> R ()
located

-- | Set layout according to combination of given 'SrcSpan's for a given.
-- Use this only when you need to set layout based on e.g. combined span of
-- several elements when there is no corresponding 'Located' wrapper
-- provided by GHC AST. It is relatively rare that this one is needed.
--
-- Given empty list this function will set layout to single line.
switchLayout ::
  -- | Span that controls layout
  [SrcSpan] ->
  -- | Computation to run with changed layout
  R () ->
  R ()
switchLayout :: [SrcSpan] -> R () -> R ()
switchLayout [SrcSpan]
spans' = Layout -> R () -> R ()
enterLayout ([SrcSpan] -> Layout
spansLayout [SrcSpan]
spans')

-- | Which layout combined spans result in?
spansLayout :: [SrcSpan] -> Layout
spansLayout :: [SrcSpan] -> Layout
spansLayout = \case
  [] -> Layout
SingleLine
  (SrcSpan
x : [SrcSpan]
xs) ->
    if SrcSpan -> Bool
isOneLineSpan ((SrcSpan -> SrcSpan -> SrcSpan) -> SrcSpan -> [SrcSpan] -> SrcSpan
forall (t :: * -> *) a b.
Foldable t =>
(a -> b -> b) -> b -> t a -> b
foldr SrcSpan -> SrcSpan -> SrcSpan
combineSrcSpans SrcSpan
x [SrcSpan]
xs)
      then Layout
SingleLine
      else Layout
MultiLine

-- | Insert a space if enclosing layout is single-line, or newline if it's
-- multiline.
--
-- > breakpoint = vlayout space newline
breakpoint :: R ()
breakpoint :: R ()
breakpoint = R () -> R () -> R ()
forall a. R a -> R a -> R a
vlayout R ()
space R ()
newline

-- | Similar to 'breakpoint' but outputs nothing in case of single-line
-- layout.
--
-- > breakpoint' = vlayout (return ()) newline
breakpoint' :: R ()
breakpoint' :: R ()
breakpoint' = R () -> R () -> R ()
forall a. R a -> R a -> R a
vlayout (() -> R ()
forall (m :: * -> *) a. Monad m => a -> m a
return ()) R ()
newline

----------------------------------------------------------------------------
-- Formatting lists

-- | Render a collection of elements inserting a separator between them.
sep ::
  -- | Separator
  R () ->
  -- | How to render an element
  (a -> R ()) ->
  -- | Elements to render
  [a] ->
  R ()
sep :: R () -> (a -> R ()) -> [a] -> R ()
sep R ()
s a -> R ()
f [a]
xs = [R ()] -> R ()
forall (t :: * -> *) (m :: * -> *) a.
(Foldable t, Monad m) =>
t (m a) -> m ()
sequence_ (R () -> [R ()] -> [R ()]
forall a. a -> [a] -> [a]
intersperse R ()
s (a -> R ()
f (a -> R ()) -> [a] -> [R ()]
forall (f :: * -> *) a b. Functor f => (a -> b) -> f a -> f b
<$> [a]
xs))

-- | Render a collection of elements layout-sensitively using given printer,
-- inserting semicolons if necessary and respecting 'useBraces' and
-- 'dontUseBraces' combinators.
--
-- > useBraces $ sepSemi txt ["foo", "bar"]
-- >   == vlayout (txt "{ foo; bar }") (txt "foo\nbar")
--
-- > dontUseBraces $ sepSemi txt ["foo", "bar"]
-- >   == vlayout (txt "foo; bar") (txt "foo\nbar")
sepSemi ::
  -- | How to render an element
  (a -> R ()) ->
  -- | Elements to render
  [a] ->
  R ()
sepSemi :: (a -> R ()) -> [a] -> R ()
sepSemi a -> R ()
f [a]
xs = R () -> R () -> R ()
forall a. R a -> R a -> R a
vlayout R ()
singleLine R ()
multiLine
  where
    singleLine :: R ()
singleLine = do
      Bool
ub <- R Bool
canUseBraces
      case [a]
xs of
        [] -> Bool -> R () -> R ()
forall (f :: * -> *). Applicative f => Bool -> f () -> f ()
when Bool
ub (R () -> R ()) -> R () -> R ()
forall a b. (a -> b) -> a -> b
$ Text -> R ()
txt Text
"{}"
        [a]
xs' ->
          if Bool
ub
            then do
              Text -> R ()
txt Text
"{ "
              R () -> (a -> R ()) -> [a] -> R ()
forall a. R () -> (a -> R ()) -> [a] -> R ()
sep (Text -> R ()
txt Text
"; ") (R () -> R ()
dontUseBraces (R () -> R ()) -> (a -> R ()) -> a -> R ()
forall b c a. (b -> c) -> (a -> b) -> a -> c
. a -> R ()
f) [a]
xs'
              Text -> R ()
txt Text
" }"
            else R () -> (a -> R ()) -> [a] -> R ()
forall a. R () -> (a -> R ()) -> [a] -> R ()
sep (Text -> R ()
txt Text
"; ") a -> R ()
f [a]
xs'
    multiLine :: R ()
multiLine =
      R () -> (a -> R ()) -> [a] -> R ()
forall a. R () -> (a -> R ()) -> [a] -> R ()
sep R ()
newline (R () -> R ()
dontUseBraces (R () -> R ()) -> (a -> R ()) -> a -> R ()
forall b c a. (b -> c) -> (a -> b) -> a -> c
. a -> R ()
f) [a]
xs

----------------------------------------------------------------------------
-- Wrapping

-- | 'BracketStyle' controlling how closing bracket is rendered.
data BracketStyle
  = -- | Normal
    N
  | -- | Shifted one level
    S

-- | Surround given entity by backticks.
backticks :: R () -> R ()
backticks :: R () -> R ()
backticks R ()
m = do
  Text -> R ()
txt Text
"`"
  R ()
m
  Text -> R ()
txt Text
"`"

-- | Surround given entity by banana brackets (i.e., from arrow notation.)
banana :: R () -> R ()
banana :: R () -> R ()
banana = Bool -> Text -> Text -> BracketStyle -> R () -> R ()
brackets_ Bool
True Text
"(|" Text
"|)" BracketStyle
N

-- | Surround given entity by curly braces @{@ and  @}@.
braces :: BracketStyle -> R () -> R ()
braces :: BracketStyle -> R () -> R ()
braces = Bool -> Text -> Text -> BracketStyle -> R () -> R ()
brackets_ Bool
False Text
"{" Text
"}"

-- | Surround given entity by square brackets @[@ and @]@.
brackets :: BracketStyle -> R () -> R ()
brackets :: BracketStyle -> R () -> R ()
brackets = Bool -> Text -> Text -> BracketStyle -> R () -> R ()
brackets_ Bool
False Text
"[" Text
"]"

-- | Surround given entity by parentheses @(@ and @)@.
parens :: BracketStyle -> R () -> R ()
parens :: BracketStyle -> R () -> R ()
parens = Bool -> Text -> Text -> BracketStyle -> R () -> R ()
brackets_ Bool
False Text
"(" Text
")"

-- | Surround given entity by @(# @ and @ #)@.
parensHash :: BracketStyle -> R () -> R ()
parensHash :: BracketStyle -> R () -> R ()
parensHash = Bool -> Text -> Text -> BracketStyle -> R () -> R ()
brackets_ Bool
True Text
"(#" Text
"#)"

-- | Braces as used for pragmas: @{-#@ and @#-}@.
pragmaBraces :: R () -> R ()
pragmaBraces :: R () -> R ()
pragmaBraces R ()
m = R () -> R ()
sitcc (R () -> R ()) -> R () -> R ()
forall a b. (a -> b) -> a -> b
$ do
  Text -> R ()
txt Text
"{-#"
  R ()
space
  R ()
m
  R ()
breakpoint
  R () -> R ()
inci (Text -> R ()
txt Text
"#-}")

-- | Surround the body with a pragma name and 'pragmaBraces'.
pragma ::
  -- | Pragma text
  Text ->
  -- | Pragma body
  R () ->
  R ()
pragma :: Text -> R () -> R ()
pragma Text
pragmaText R ()
body = R () -> R ()
pragmaBraces (R () -> R ()) -> R () -> R ()
forall a b. (a -> b) -> a -> b
$ do
  Text -> R ()
txt Text
pragmaText
  R ()
breakpoint
  R ()
body

-- | A helper for defining wrappers like 'parens' and 'braces'.
brackets_ ::
  -- | Insert breakpoints around brackets
  Bool ->
  -- | Opening bracket
  Text ->
  -- | Closing bracket
  Text ->
  -- | Bracket style
  BracketStyle ->
  -- | Inner expression
  R () ->
  R ()
brackets_ :: Bool -> Text -> Text -> BracketStyle -> R () -> R ()
brackets_ Bool
needBreaks Text
open Text
close BracketStyle
style R ()
m = R () -> R ()
sitcc (R () -> R () -> R ()
forall a. R a -> R a -> R a
vlayout R ()
singleLine R ()
multiLine)
  where
    singleLine :: R ()
singleLine = do
      Text -> R ()
txt Text
open
      Bool -> R () -> R ()
forall (f :: * -> *). Applicative f => Bool -> f () -> f ()
when Bool
needBreaks R ()
space
      R ()
m
      Bool -> R () -> R ()
forall (f :: * -> *). Applicative f => Bool -> f () -> f ()
when Bool
needBreaks R ()
space
      Text -> R ()
txt Text
close
    multiLine :: R ()
multiLine = do
      Text -> R ()
txt Text
open
      if Bool
needBreaks
        then R ()
newline R () -> R () -> R ()
forall (m :: * -> *) a b. Monad m => m a -> m b -> m b
>> R () -> R ()
inci R ()
m
        else R ()
space R () -> R () -> R ()
forall (m :: * -> *) a b. Monad m => m a -> m b -> m b
>> R () -> R ()
sitcc R ()
m
      R ()
newline
      case BracketStyle
style of
        BracketStyle
N -> Text -> R ()
txt Text
close
        BracketStyle
S -> R () -> R ()
inci (Text -> R ()
txt Text
close)

----------------------------------------------------------------------------
-- Literals

-- | Print @,@.
comma :: R ()
comma :: R ()
comma = Text -> R ()
txt Text
","

-- | Print @=@. Do not use @'txt' "="@.
equals :: R ()
equals :: R ()
equals = Text -> R ()
interferingTxt Text
"="