----------------------------------------------------------------------------- -- | -- Module : Text.Parsec.Pos -- Copyright : (c) Daan Leijen 1999-2001, (c) Paolo Martini 2007 -- License : BSD-style (see the LICENSE file) -- -- Maintainer : derek.a.elkins@gmail.com -- Stability : provisional -- Portability : portable -- -- Textual source positions. -- ----------------------------------------------------------------------------- module Text.Parsec.Pos ( SourceName, Line, Column , SourcePos , sourceLine, sourceColumn, sourceName , incSourceLine, incSourceColumn , setSourceLine, setSourceColumn, setSourceName , newPos, initialPos , updatePosChar, updatePosString ) where #ifdef BASE3 import Data.Generics #else import Data.Data (Data) import Data.Typeable (Typeable) #endif -- < Source positions: a file name, a line and a column -- upper left is (1,1) type SourceName = String type Line = Int type Column = Int -- | The abstract data type @SourcePos@ represents source positions. It -- contains the name of the source (i.e. file name), a line number and -- a column number. @SourcePos@ is an instance of the 'Show', 'Eq' and -- 'Ord' class. data SourcePos = SourcePos SourceName !Line !Column deriving ( Eq, Ord, Data, Typeable) -- | Create a new 'SourcePos' with the given source name, -- line number and column number. newPos :: SourceName -> Line -> Column -> SourcePos newPos name line column = SourcePos name line column -- | Create a new 'SourcePos' with the given source name, -- and line number and column number set to 1, the upper left. initialPos :: SourceName -> SourcePos initialPos name = newPos name 1 1 -- | Extracts the name of the source from a source position. sourceName :: SourcePos -> SourceName sourceName (SourcePos name _line _column) = name -- | Extracts the line number from a source position. sourceLine :: SourcePos -> Line sourceLine (SourcePos _name line _column) = line -- | Extracts the column number from a source position. sourceColumn :: SourcePos -> Column sourceColumn (SourcePos _name _line column) = column -- | Increments the line number of a source position. incSourceLine :: SourcePos -> Line -> SourcePos incSourceLine (SourcePos name line column) n = SourcePos name (line+n) column -- | Increments the column number of a source position. incSourceColumn :: SourcePos -> Column -> SourcePos incSourceColumn (SourcePos name line column) n = SourcePos name line (column+n) -- | Set the name of the source. setSourceName :: SourcePos -> SourceName -> SourcePos setSourceName (SourcePos _name line column) n = SourcePos n line column -- | Set the line number of a source position. setSourceLine :: SourcePos -> Line -> SourcePos setSourceLine (SourcePos name _line column) n = SourcePos name n column -- | Set the column number of a source position. setSourceColumn :: SourcePos -> Column -> SourcePos setSourceColumn (SourcePos name line _column) n = SourcePos name line n -- | The expression @updatePosString pos s@ updates the source position -- @pos@ by calling 'updatePosChar' on every character in @s@, ie. -- @foldl updatePosChar pos string@. updatePosString :: SourcePos -> String -> SourcePos updatePosString pos string = foldl updatePosChar pos string -- | Update a source position given a character. If the character is a -- newline (\'\\n\') or carriage return (\'\\r\') the line number is -- incremented by 1. If the character is a tab (\'\t\') the column -- number is incremented to the nearest 8'th column, ie. @column + 8 - -- ((column-1) \`mod\` 8)@. In all other cases, the column is -- incremented by 1. updatePosChar :: SourcePos -> Char -> SourcePos updatePosChar (SourcePos name line column) c = case c of '\n' -> SourcePos name (line+1) 1 '\t' -> SourcePos name line (column + 8 - ((column-1) `mod` 8)) _ -> SourcePos name line (column + 1) instance Show SourcePos where show (SourcePos name line column) | null name = showLineColumn | otherwise = "\"" ++ name ++ "\" " ++ showLineColumn where showLineColumn = "(line " ++ show line ++ ", column " ++ show column ++ ")"