https://github.com/battermann/parser-combinators-scala-hands-on

A series of exercises on functional parsers
https://github.com/battermann/parser-combinators-scala-hands-on

functional-programming hands-on parser-combinators property-based-testing scala tutorial

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A series of exercises on functional parsers

• Host: GitHub
• URL: https://github.com/battermann/parser-combinators-scala-hands-on
• Owner: battermann
• Created: 2018-02-01T23:04:23.000Z (almost 7 years ago)
• Default Branch: exercises
• Last Pushed: 2020-04-27T20:59:02.000Z (over 4 years ago)
• Last Synced: 2024-10-23T07:24:14.666Z (3 months ago)
• Topics: functional-programming, hands-on, parser-combinators, property-based-testing, scala, tutorial
• Language: Scala
• Homepage:
• Size: 9.77 KB
• Stars: 2
• Watchers: 4
• Forks: 1
• Open Issues: 0
• Metadata Files:
  • Readme: README.md

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README

        
# A Hands On Functional Parsers In Scala

> A hands on functional parsers in Scala based on "Programming in Haskell" by Graham Hutton.

## Prerequisites

- Install [Ammonite](https://ammonite.io/#ScalaScripts)

## How To

This repo has two branches, `exercises` and `solutions`.

Checkout the `exercises` branch and run the tests with `amm -w test.sc`.

You should get an output similar to this:

```text

tests$ParserTests:

- fail should always fail

- succeed should always succeed with the result value v (pending)

- anyChar should succeed with first char for non empty inputs (pending)

- anyChar should fail if input is empty (pending)

- sequencing (pending)

…

```

Now, take look at the tests in `tests.sc`. Here is an example:

```scala

property("fail should always fail") {

  pending

  forAll { (input: String) =>

    parser.fail(input) should ===(None)

  }

}

```

- Go from top to bottom

- Remove the line which says `pending` from the first pending test

- This should usually make the test fail (red)

- Now implement the function under test (in `parser.sc` and `expr_parser.sc`) and try to make the test pass (green)

- Think about if you can improve your implementation (refactor)

- Work through the tests from top to bottom until all tests pass