Avatar of fhuttere

fhuttere's solution

to Pig Latin in the C# Track

Published at Jul 13 2018 · 1 comment
Instructions
Test suite
Solution

Note:

This solution was written on an old version of Exercism. The tests below might not correspond to the solution code, and the exercise may have changed since this code was written.

Implement a program that translates from English to Pig Latin.

Pig Latin is a made-up children's language that's intended to be confusing. It obeys a few simple rules (below), but when it's spoken quickly it's really difficult for non-children (and non-native speakers) to understand.

  • Rule 1: If a word begins with a vowel sound, add an "ay" sound to the end of the word.
  • Rule 2: If a word begins with a consonant sound, move it to the end of the word, and then add an "ay" sound to the end of the word.

There are a few more rules for edge cases, and there are regional variants too.

See http://en.wikipedia.org/wiki/Pig_latin for more details.

Source

The Pig Latin exercise at Test First Teaching by Ultrasaurus https://github.com/ultrasaurus/test-first-teaching/blob/master/learn_ruby/pig_latin/

Submitting Incomplete Solutions

It's possible to submit an incomplete solution so you can see how others have completed the exercise.

PigLatinTest.cs

// This file was auto-generated based on version 1.2.0 of the canonical data.

using Xunit;

public class PigLatinTest
{
    [Fact]
    public void Word_beginning_with_a()
    {
        Assert.Equal("appleay", PigLatin.Translate("apple"));
    }

    [Fact(Skip = "Remove to run test")]
    public void Word_beginning_with_e()
    {
        Assert.Equal("earay", PigLatin.Translate("ear"));
    }

    [Fact(Skip = "Remove to run test")]
    public void Word_beginning_with_i()
    {
        Assert.Equal("iglooay", PigLatin.Translate("igloo"));
    }

    [Fact(Skip = "Remove to run test")]
    public void Word_beginning_with_o()
    {
        Assert.Equal("objectay", PigLatin.Translate("object"));
    }

    [Fact(Skip = "Remove to run test")]
    public void Word_beginning_with_u()
    {
        Assert.Equal("underay", PigLatin.Translate("under"));
    }

    [Fact(Skip = "Remove to run test")]
    public void Word_beginning_with_a_vowel_and_followed_by_a_qu()
    {
        Assert.Equal("equalay", PigLatin.Translate("equal"));
    }

    [Fact(Skip = "Remove to run test")]
    public void Word_beginning_with_p()
    {
        Assert.Equal("igpay", PigLatin.Translate("pig"));
    }

    [Fact(Skip = "Remove to run test")]
    public void Word_beginning_with_k()
    {
        Assert.Equal("oalakay", PigLatin.Translate("koala"));
    }

    [Fact(Skip = "Remove to run test")]
    public void Word_beginning_with_x()
    {
        Assert.Equal("enonxay", PigLatin.Translate("xenon"));
    }

    [Fact(Skip = "Remove to run test")]
    public void Word_beginning_with_q_without_a_following_u()
    {
        Assert.Equal("atqay", PigLatin.Translate("qat"));
    }

    [Fact(Skip = "Remove to run test")]
    public void Word_beginning_with_ch()
    {
        Assert.Equal("airchay", PigLatin.Translate("chair"));
    }

    [Fact(Skip = "Remove to run test")]
    public void Word_beginning_with_qu()
    {
        Assert.Equal("eenquay", PigLatin.Translate("queen"));
    }

    [Fact(Skip = "Remove to run test")]
    public void Word_beginning_with_qu_and_a_preceding_consonant()
    {
        Assert.Equal("aresquay", PigLatin.Translate("square"));
    }

    [Fact(Skip = "Remove to run test")]
    public void Word_beginning_with_th()
    {
        Assert.Equal("erapythay", PigLatin.Translate("therapy"));
    }

    [Fact(Skip = "Remove to run test")]
    public void Word_beginning_with_thr()
    {
        Assert.Equal("ushthray", PigLatin.Translate("thrush"));
    }

    [Fact(Skip = "Remove to run test")]
    public void Word_beginning_with_sch()
    {
        Assert.Equal("oolschay", PigLatin.Translate("school"));
    }

    [Fact(Skip = "Remove to run test")]
    public void Word_beginning_with_yt()
    {
        Assert.Equal("yttriaay", PigLatin.Translate("yttria"));
    }

    [Fact(Skip = "Remove to run test")]
    public void Word_beginning_with_xr()
    {
        Assert.Equal("xrayay", PigLatin.Translate("xray"));
    }

    [Fact(Skip = "Remove to run test")]
    public void Y_is_treated_like_a_consonant_at_the_beginning_of_a_word()
    {
        Assert.Equal("ellowyay", PigLatin.Translate("yellow"));
    }

    [Fact(Skip = "Remove to run test")]
    public void Y_is_treated_like_a_vowel_at_the_end_of_a_consonant_cluster()
    {
        Assert.Equal("ythmrhay", PigLatin.Translate("rhythm"));
    }

    [Fact(Skip = "Remove to run test")]
    public void Y_as_second_letter_in_two_letter_word()
    {
        Assert.Equal("ymay", PigLatin.Translate("my"));
    }

    [Fact(Skip = "Remove to run test")]
    public void A_whole_phrase()
    {
        Assert.Equal("ickquay astfay unray", PigLatin.Translate("quick fast run"));
    }
}
namespace exercism.piglatin
{
    using System.Linq;
    using System.Text;
    using System.Text.RegularExpressions;

    public static class PigLatin
    {
        private const string WordEnding = "ay";
        private const string VowelPattern = @"^(a|e|i|o|u|yt|xr)[\w]+";
        private const string SpecialConsonantsPattern = @"^(ch|qu|thr|th|sch)[\w]+";
        private const string SpecialConsonantsStartPattern = @"^(ch|qu|thr|th|sch)";
        private const string CombiningConsonantsPattern = @"([\w]){1}(qu)[\w]+";
        private const string CombiningConsonantsStartPattern = @"([\w]){1}(qu)";

        private static readonly Regex WordSplitterPattern = new Regex(@"[\w]+(['-][\w]+)?", RegexOptions.Compiled);

        public static string Translate(string phrase)
        {
            var words = WordSplitterPattern.Matches(phrase).Cast<Match>().GroupBy(match => match.Captures[0].Value).Select(group => group.Key);
            var translated = new StringBuilder();

            foreach (var word in words)
            {
                translated.AppendFormat("{0} ", TranslateWord(word));
            }

            return translated.ToString().TrimEnd();
        }

        private static string TranslateWord(string word)
        {
            var translated = new StringBuilder(word);
            string startingConsonant = null;

            if (Regex.IsMatch(word, VowelPattern))
            {
                //easiest case, simply append the ending
                translated.Append(WordEnding);
            }
            else if (Regex.IsMatch(word, SpecialConsonantsPattern))
            {
                //word starts with multi-letter consonant
                startingConsonant = Regex.Match(word, SpecialConsonantsStartPattern).Value;
                translated.Remove(0, startingConsonant.Length);
                translated.AppendFormat("{0}{1}", startingConsonant, WordEnding);
            }
            else if (Regex.IsMatch(word, CombiningConsonantsPattern))
            {
                //consonant preceded by single consonant
                startingConsonant = Regex.Match(word, CombiningConsonantsStartPattern).Value;
                translated.Remove(0, startingConsonant.Length);
                translated.AppendFormat("{0}{1}", startingConsonant, WordEnding);
            }
            else
            {
                //truly single consonants
                startingConsonant = word.Substring(0, 1) + WordEnding;
                translated.Remove(0, 1);
                translated.Append(startingConsonant);
            }

            return translated.ToString();
        }
    }
}

Community comments

Find this solution interesting? Ask the author a question to learn more.
Avatar of martinfreedman

Good, now you can refactor this into two regexs

What can you learn from this solution?

A huge amount can be learned from reading other people’s code. This is why we wanted to give exercism users the option of making their solutions public.

Here are some questions to help you reflect on this solution and learn the most from it.

  • What compromises have been made?
  • Are there new concepts here that you could read more about to improve your understanding?