content: {-
  SPDX-License-Identifier: AGPL-3.0-only
  
  This file is part of `statebox/cql`, the categorical query language.
  
  Copyright (C) 2019 Stichting Statebox <https://statebox.nl>
  
  This program is free software: you can redistribute it and/or modify
  it under the terms of the GNU Affero General Public License as published by
  the Free Software Foundation, either version 3 of the License, or
  (at your option) any later version.
  
  This program is distributed in the hope that it will be useful,
  but WITHOUT ANY WARRANTY; without even the implied warranty of
  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  GNU Affero General Public License for more details.
  
  You should have received a copy of the GNU Affero General Public License
  along with this program.  If not, see <https://www.gnu.org/licenses/>.
  -}
  module Language.CQL.Parser.LexerRules where
  
  -- megaparsec
  import           Text.Megaparsec
  import           Text.Megaparsec.Char
  import qualified Text.Megaparsec.Char.Lexer as L
  
  -- void
  import           Data.Void
  
  type Parser = Parsec Void String
  
  spaceConsumer :: Parser ()
  spaceConsumer = L.space space1 lineComment blockComment
    where
      lineComment = L.skipLineComment "//"
      blockComment = L.skipBlockComment "(*" "*)" <|> L.skipBlockComment "/*" "*/"
  
  lexeme :: Parser a -> Parser a
  lexeme = L.lexeme spaceConsumer
  
  idChar :: Parser Char
  idChar = letterChar <|> char '_' <|> char '$'
  
  upperId :: Parser String
  upperId = (:) <$> upperChar <*> many (idChar <|> digitChar)
  
  lowerId :: Parser String
  lowerId = (:) <$> lowerChar <*> many (idChar <|> digitChar)
  
  specialId :: Parser String
  specialId = (:) <$> idChar <*> many (idChar <|> digitChar)
  