CODEWITHSUNDEEP
scalatestingparser-combinators
user1868607
user1868607

Reputation: 2600

Create tests for parser combinators II in Scala

Consider this source code that implements a parser for a term language in Scala. The main function, designed to test its functionality is defined as:

def main(args: Array[String]): Unit = {
    val stdin = new java.io.BufferedReader(new java.io.InputStreamReader(System.in))
    val tokens = new lexical.Scanner(stdin.readLine())
    phrase(term)(tokens) match {
      case Success(trees, _) =>
        for (t <- path(trees))
          println(t)
        try {
          print("Big step: ")
          println(eval(trees))
        } catch {
          case TermIsStuck(t) => println("Stuck term: " + t)
        }
      case e =>
        println(e)
    }
  }

I wrote the following test:

package fos

import org.scalatest.FunSuite


class ArithmeticTest extends FunSuite {

  test("testTerm") {

    Arithmetic.term(new Arithmetic.lexical.Scanner("if iszero pred pred 2 then if iszero 0 then true else false else false")) match {
      case Success(res,next) => assert(res == If(IsZero(Pred(Pred(Succ(Succ(Zero))))),If(IsZero(Zero),True,False),False))
      case Failure(msg,next) => assert(false)
    }
  }

}

Unfortunately, the Success and Failure cases are not recognized even if I mix-in StandardTokenParsers like in the link above. How can I get it working?

Upvotes: 0

Views: 18

Answers (1)

Alexey Romanov
Alexey Romanov

Reputation: 170745

You need Arithmetic.Success and Arithmetic.Failure, just like you have Arithmetic.lexical.Scanner. Alternatively, you could import Arithmetic._.

Upvotes: 1

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