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| 1 | +-- | Pretty debug trace |
| 2 | + |
| 3 | +module Text.Show.Pretty |
| 4 | + ( prettify |
| 5 | + , FoldingOption(..) |
| 6 | + ) where |
| 7 | + |
| 8 | +import Prelude hiding (between) |
| 9 | +import Data.Either |
| 10 | +import Data.Foldable (for_) |
| 11 | +import Data.List |
| 12 | +import Data.List.Lazy as LL |
| 13 | +import Data.Maybe |
| 14 | +import Data.String as Str |
| 15 | +import Data.Tuple |
| 16 | +import Control.Alt ((<|>)) |
| 17 | +import Control.Lazy (fix) |
| 18 | +import Text.Parsing.Parser (Parser, runParser) |
| 19 | +import Text.Parsing.Parser.Combinators (between, notFollowedBy, sepBy, try) |
| 20 | +import Text.Parsing.Parser.Language (haskell) |
| 21 | +import Text.Parsing.Parser.String (anyChar, char, satisfy, skipSpaces, string) |
| 22 | +import Text.Parsing.Parser.Json (jsonString) |
| 23 | +import Control.Monad.RWS |
| 24 | + |
| 25 | + |
| 26 | +-- | Folding option for show. |
| 27 | +data FoldingOption = UnfoldLevel Int | FoldToWidth Int |
| 28 | + |
| 29 | +-- | Parse string and show it with options. |
| 30 | +prettify :: {folding :: FoldingOption} -> String -> String |
| 31 | +prettify options str = case runParser str exprsParser of |
| 32 | + Right expr -> prettyShow options expr |
| 33 | + _ -> str |
| 34 | + |
| 35 | + |
| 36 | +-- | Expresssion data type. Representation of parsed text. |
| 37 | +data Expr = |
| 38 | + Raw String |
| 39 | + | StringExpr String |
| 40 | + | CharExpr Char |
| 41 | + | ListExpr String String (List (List Expr)) |
| 42 | + |
| 43 | +-- | Parser for expressions. |
| 44 | +exprsParser :: Parser String (List Expr) |
| 45 | +exprsParser = |
| 46 | + many $ (try $ fix \p -> |
| 47 | + listExpr "{" "}" p |
| 48 | + <|> listExpr "[" "]" p |
| 49 | + <|> listExpr "(" ")" p |
| 50 | + <|> StringExpr <$> (try haskell.stringLiteral <|> jsonString) |
| 51 | + <|> CharExpr <$> try haskell.charLiteral |
| 52 | + <|> Raw <$> Str.singleton <$> |
| 53 | + (notFollowedBy (skipSpaces *> (satisfy \c -> c == '}' || c == ']' || c == ')' || c == ',')) *> anyChar) |
| 54 | + ) <|> (Raw <$> Str.singleton <$> anyChar) |
| 55 | + where |
| 56 | + listExpr leftBracket rightBracket p = ListExpr leftBracket rightBracket <$> |
| 57 | + between (string leftBracket <* skipSpaces) (skipSpaces *> string rightBracket) |
| 58 | + (many p `sepBy` (try $ skipSpaces *> char ',' <* skipSpaces)) |
| 59 | + |
| 60 | + |
| 61 | +type PrintState = { |
| 62 | + modeStack :: List (Maybe Mode), |
| 63 | + column :: Int, |
| 64 | + commitingOneLineMode :: Boolean, |
| 65 | + stage' :: Maybe {tokens :: List ShowToken, column :: Int} } |
| 66 | + |
| 67 | +notPrinted :: PrintState |
| 68 | +notPrinted = { |
| 69 | + modeStack: Nil, |
| 70 | + column: 0, |
| 71 | + commitingOneLineMode: false, |
| 72 | + stage': Nothing } |
| 73 | + |
| 74 | +data Mode = OneLineMode | MultiLineMode |
| 75 | +derive instance eqMode :: Eq Mode |
| 76 | + |
| 77 | +data ShowToken = Regular String | OnlyIn Mode String | NewMode | EndMode |
| 78 | +derive instance eqShowToken :: Eq ShowToken |
| 79 | + |
| 80 | +-- | Show parsed expressions. |
| 81 | +prettyShow :: {folding :: FoldingOption} -> List Expr -> String |
| 82 | +prettyShow options exprs = |
| 83 | + let Tuple _ w = execRWS (prettyWrite exprs *> commit OneLineMode) options notPrinted |
| 84 | + in w |
| 85 | + where |
| 86 | + prettyWrite :: List Expr -> RWS {folding :: FoldingOption} String PrintState Unit |
| 87 | + prettyWrite Nil = pure unit |
| 88 | + prettyWrite (expr:restExprs) = do |
| 89 | + case expr of |
| 90 | + ListExpr leftBracket rightBracket (Nil:Nil) -> write_ leftBracket *> write_ rightBracket |
| 91 | + ListExpr leftBracket rightBracket ess -> do |
| 92 | + write_ leftBracket |
| 93 | + write NewMode |
| 94 | + nestingLevel <- getNestingLevel |
| 95 | + forL_ ess \{elem: es, isLast} -> do |
| 96 | + write $ "\n" `onlyIn` MultiLineMode |
| 97 | + void $ LL.replicateM nestingLevel $ write $ " " `onlyIn` MultiLineMode |
| 98 | + prettyWrite es |
| 99 | + unless isLast do |
| 100 | + write_ "," |
| 101 | + write $ " " `onlyIn` OneLineMode |
| 102 | + write $ " " `onlyIn` MultiLineMode |
| 103 | + write_ rightBracket |
| 104 | + write EndMode |
| 105 | + Raw s -> write_ s |
| 106 | + StringExpr s -> do |
| 107 | + write_ "\"" |
| 108 | + write_ $ |
| 109 | + Str.replaceAll (Str.Pattern "\"") (Str.Replacement "\\\"") $ |
| 110 | + Str.replaceAll (Str.Pattern "\\") (Str.Replacement "\\\\") s |
| 111 | + write_ "\"" |
| 112 | + CharExpr c -> write_ "'" *> write_ (Str.singleton c) *> write_ "'" |
| 113 | + prettyWrite restExprs |
| 114 | + |
| 115 | + onlyIn str mode = OnlyIn mode str |
| 116 | + |
| 117 | + write_ str = write $ Regular str |
| 118 | + |
| 119 | + write token = do |
| 120 | + mode <- getMode |
| 121 | + let matched = case mode of |
| 122 | + Nothing -> true |
| 123 | + Just m -> case token of |
| 124 | + OnlyIn m' _ -> m == m' |
| 125 | + _ -> true |
| 126 | + when matched do |
| 127 | + state <- get |
| 128 | + let str = case token of |
| 129 | + Regular s -> s |
| 130 | + OnlyIn _ s -> s |
| 131 | + _ -> "" |
| 132 | + if isNothing mode || isJust state.stage' && str /= "\n" |
| 133 | + then do |
| 134 | + let engaged = case token of |
| 135 | + Regular _ -> true |
| 136 | + OnlyIn OneLineMode _ -> true |
| 137 | + OnlyIn MultiLineMode _ -> case mode of |
| 138 | + Just MultiLineMode -> true |
| 139 | + _ -> false |
| 140 | + _ -> false |
| 141 | + let len = if engaged then Str.length str else 0 |
| 142 | + let stage = fromMaybe {tokens: Nil, column: state.column} state.stage' |
| 143 | + stage2 = stage {tokens = token : stage.tokens, column = stage.column + len} |
| 144 | + put state {stage' = Just stage2} |
| 145 | + {folding} <- ask |
| 146 | + case folding of |
| 147 | + FoldToWidth maxWidth -> |
| 148 | + when (stage2.column > maxWidth) do |
| 149 | + commit MultiLineMode |
| 150 | + _ -> pure unit |
| 151 | + else do |
| 152 | + if str == "\n" |
| 153 | + then commit OneLineMode *> modify \st -> st {column = 0} |
| 154 | + else modify \st -> st {column = st.column + Str.length str} |
| 155 | + tell str |
| 156 | + when (token == NewMode) do |
| 157 | + modeAfter mode >>= pushMode |
| 158 | + when (token == EndMode) do |
| 159 | + popMode |
| 160 | + |
| 161 | + modeAfter (Just OneLineMode) = pure $ Just OneLineMode |
| 162 | + modeAfter (Just MultiLineMode) = do |
| 163 | + {folding} <- ask |
| 164 | + case folding of |
| 165 | + UnfoldLevel maxLevel -> do |
| 166 | + nestingLevel <- getNestingLevel |
| 167 | + pure $ Just if nestingLevel >= maxLevel then OneLineMode else MultiLineMode |
| 168 | + FoldToWidth 0 -> pure $ Just MultiLineMode |
| 169 | + FoldToWidth _ -> do |
| 170 | + {commitingOneLineMode} <- get |
| 171 | + pure if commitingOneLineMode then Just OneLineMode else Nothing |
| 172 | + modeAfter Nothing = pure Nothing |
| 173 | + |
| 174 | + getNestingLevel = get >>= \st -> pure $ length st.modeStack |
| 175 | + |
| 176 | + getMode = get >>= \st -> pure $ fromMaybe (Just MultiLineMode) $ head st.modeStack |
| 177 | + |
| 178 | + pushMode mode = modify \st -> st {modeStack = mode : st.modeStack} |
| 179 | + |
| 180 | + popMode = do |
| 181 | + {modeStack} <- get |
| 182 | + let m = fromMaybe {head: (Just MultiLineMode), tail: Nil} (uncons modeStack) |
| 183 | + modify \st -> st {modeStack = m.tail} |
| 184 | + |
| 185 | + commit mode = do |
| 186 | + {stage'} <- get |
| 187 | + case stage' of |
| 188 | + Nothing -> pure unit |
| 189 | + Just stage -> do |
| 190 | + modify \st -> st {modeStack = dropWhile isNothing st.modeStack, stage' = Nothing} |
| 191 | + let tokens = reverse stage.tokens |
| 192 | + when (mode == OneLineMode) do |
| 193 | + modify \st -> st {commitingOneLineMode = true} |
| 194 | + pushMode $ Just mode |
| 195 | + for_ tokens |
| 196 | + write |
| 197 | + modify \st -> st {commitingOneLineMode = false} |
| 198 | + |
| 199 | +-- | Traverse with information about position, ignoring the final result. |
| 200 | +forL_ :: forall a b m. Applicative m => List a -> ({elem :: a, isLast :: Boolean} -> m b) -> m Unit |
| 201 | +forL_ Nil _ = pure unit |
| 202 | +forL_ (x:Nil) f = void $ f {elem: x, isLast: true} |
| 203 | +forL_ (x:xs) f = f {elem: x, isLast: false} *> forL_ xs f |
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