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| 1 | +package scala.util.parsing.combinator |
| 2 | + |
| 3 | +import org.junit.Test |
| 4 | +import org.junit.Assert.assertEquals |
| 5 | + |
| 6 | +class RegexParsersTest { |
| 7 | + @Test |
| 8 | + def parserNoSuccessMessage: Unit = { |
| 9 | + object parser extends RegexParsers { |
| 10 | + def sign = "-" |
| 11 | + def number = "\\d+".r |
| 12 | + type ResultType = Option[String] ~ String |
| 13 | + def p: Parser[ResultType] = sign.? ~ number withErrorMessage "Number expected!" |
| 14 | + def q: Parser[ResultType] = sign.? ~! number withErrorMessage "Number expected!" |
| 15 | + } |
| 16 | + import parser._ |
| 17 | + def extractResult(r: ParseResult[ResultType]): ResultType = r match { |
| 18 | + case Success(r, _) => r |
| 19 | + case r => sys.error(r.toString) |
| 20 | + } |
| 21 | + def result(num: Int): ResultType = { |
| 22 | + val minusSign = if (num < 0) Some("-") else None |
| 23 | + val absNumStr = Math.abs(num).toString |
| 24 | + new ~(minusSign, absNumStr) |
| 25 | + } |
| 26 | + |
| 27 | + val failure1 = parseAll(p, "-x").asInstanceOf[Failure] |
| 28 | + assertEquals("string matching regex `\\d+' expected but `x' found", failure1.msg) |
| 29 | + val failure2 = parseAll(p, "x").asInstanceOf[Failure] |
| 30 | + assertEquals("string matching regex `\\d+' expected but `x' found", failure2.msg) |
| 31 | + assertEquals(result(-5), extractResult(parseAll(p, "-5"))) |
| 32 | + assertEquals(result(5), extractResult(parseAll(p, "5"))) |
| 33 | + val error1 = parseAll(q, "-x").asInstanceOf[Error] |
| 34 | + assertEquals("Number expected!", error1.msg) |
| 35 | + val error2 = parseAll(q, "x").asInstanceOf[Error] |
| 36 | + assertEquals("Number expected!", error2.msg) |
| 37 | + assertEquals(result(-5), extractResult(parseAll(q, "-5"))) |
| 38 | + assertEquals(result(5), extractResult(parseAll(q, "5"))) |
| 39 | + } |
| 40 | + |
| 41 | + @Test |
| 42 | + def parserFilter: Unit = { |
| 43 | + object parser extends RegexParsers { |
| 44 | + val keywords = Set("if", "false") |
| 45 | + def word: Parser[String] = "\\w+".r |
| 46 | + |
| 47 | + def keyword: Parser[String] = word filter (keywords.contains) |
| 48 | + def ident: Parser[String] = word filter(!keywords.contains(_)) |
| 49 | + |
| 50 | + def test: Parser[String ~ String] = keyword ~ ident |
| 51 | + } |
| 52 | + import parser._ |
| 53 | + |
| 54 | + val failure1 = parseAll(test, "if false").asInstanceOf[Failure] |
| 55 | + assertEquals("Input doesn't match filter: false", failure1.msg) |
| 56 | + val failure2 = parseAll(test, "not true").asInstanceOf[Failure] |
| 57 | + assertEquals("Input doesn't match filter: not", failure2.msg) |
| 58 | + val success = parseAll(test, "if true").asInstanceOf[Success[String ~ String]] |
| 59 | + assertEquals(new ~("if", "true"), success.get) |
| 60 | + } |
| 61 | + |
| 62 | + @Test |
| 63 | + def parserForFilter: Unit = { |
| 64 | + object parser extends RegexParsers { |
| 65 | + def word: Parser[String] = "\\w+".r |
| 66 | + |
| 67 | + def twoWords = for { |
| 68 | + (a ~ b) <- word ~ word |
| 69 | + } yield (b, a) |
| 70 | + } |
| 71 | + import parser._ |
| 72 | + |
| 73 | + val success = parseAll(twoWords, "first second").asInstanceOf[Success[(String, String)]] |
| 74 | + assertEquals(("second", "first"), success.get) |
| 75 | + } |
| 76 | +} |
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