diff options
Diffstat (limited to 'docs/examples/parsing/ArithmeticParser.scala')
-rw-r--r-- | docs/examples/parsing/ArithmeticParser.scala | 14 |
1 files changed, 7 insertions, 7 deletions
diff --git a/docs/examples/parsing/ArithmeticParser.scala b/docs/examples/parsing/ArithmeticParser.scala index e8fbee4499..99cf7a5578 100644 --- a/docs/examples/parsing/ArithmeticParser.scala +++ b/docs/examples/parsing/ArithmeticParser.scala @@ -15,16 +15,16 @@ import scala.util.parsing.combinator.syntactical.StdTokenParsers * a term is a sequence of factors, separated by * or / * a factor is a parenthesized expression or a number * - * @author Adriaan Moors - */ -object arithmeticParser extends StdTokenParsers { + * @author Adriaan Moors + */ +object arithmeticParser extends StdTokenParsers { type Tokens = StdLexical ; val lexical = new StdLexical lexical.delimiters ++= List("(", ")", "+", "-", "*", "/") lazy val expr = term*("+" ^^^ {(x: int, y: int) => x + y} | "-" ^^^ {(x: int, y: int) => x - y}) lazy val term = factor*("*" ^^^ {(x: int, y: int) => x * y} | "/" ^^^ {(x: int, y: int) => x / y}) lazy val factor: Parser[int] = "(" ~> expr <~ ")" | numericLit ^^ (_.toInt) - + def main(args: Array[String]) { println( if (args.length == 1) { @@ -37,14 +37,14 @@ object arithmeticParser extends StdTokenParsers { } -object arithmeticParserDesugared extends StdTokenParsers { +object arithmeticParserDesugared extends StdTokenParsers { type Tokens = StdLexical ; val lexical = new StdLexical lexical.delimiters ++= List("(", ")", "+", "-", "*", "/") lazy val expr = chainl1(term, (keyword("+").^^^{(x: int, y: int) => x + y}).|(keyword("-").^^^{(x: int, y: int) => x - y})) lazy val term = chainl1(factor, (keyword("*").^^^{(x: int, y: int) => x * y}).|(keyword("/").^^^{(x: int, y: int) => x / y})) - lazy val factor: Parser[int] = keyword("(").~>(expr.<~(keyword(")"))).|(numericLit.^^(x => x.toInt)) - + lazy val factor: Parser[int] = keyword("(").~>(expr.<~(keyword(")"))).|(numericLit.^^(x => x.toInt)) + def main(args: Array[String]) { println( if (args.length == 1) { |