private static void Step2(StringBuilder word, StemRegion stemRegion)
{
var replacement = word.EndsWith(step2Replacements);
var length = word.Length;
if (replacement.MatchWord != null && length - replacement.MatchWord.Length >= stemRegion.R1)
{
switch (replacement.MatchWord)
{
case "OGI":
if (length > 3 && word[length - replacement.MatchWord.Length - 1] == 'L')
{
word.ReplaceEnd(replacement);
}
break;
case "LI":
if (length > 1 && IsRemovableLiEnding(word[length - 3]))
{
word.Length -= 2;
}
break;
default:
word.ReplaceEnd(replacement);
break;
}
}
}
private static void Step1b(StringBuilder word, StemRegion stemRegion)
{
var replacement = word.EndsWith(step1bReplacements);
var matchedWord = replacement.MatchWord;
if (matchedWord != null)
{
switch (matchedWord)
{
case "EEDLY":
case "EED":
if (word.Length - matchedWord.Length >= stemRegion.R1)
{
word.ReplaceEnd(replacement);
}
break;
default:
var found = false;
for (var j = 0; j < word.Length - matchedWord.Length; ++j)
{
if (word.IsVowel(j))
{
word.ReplaceEnd(replacement);
found = true;
break;
}
}
if (found)
{
if (word.EndsWith(step1bAppendEEndings) != null)
{
word.Append('E');
}
else if (HasDoubleLetterEnding(word))
{
word.Length -= 1;
}
else if (word.IsShortWord(stemRegion))
{
word.Append('E');
}
}
break;
}
}
}
private static void Step4(StringBuilder word, StemRegion stemRegion)
{
var replacement = word.EndsWith(step4Replacements);
if (replacement.MatchWord != null && word.Length - replacement.MatchWord.Length >= stemRegion.R2)
{
if (replacement.MatchWord == "ION")
{
if (word.Length > 3 && IsRemovableIonEnding(word[word.Length - 4]))
{
word.Length -= replacement.MatchWord.Length;
}
}
else
{
word.Length -= replacement.MatchWord.Length;
}
}
}
private static void Step3(StringBuilder word, StemRegion stemRegion)
{
var replacement = word.EndsWith(step3Replacements);
if (replacement.MatchWord != null && word.Length - replacement.MatchWord.Length >= stemRegion.R1)
{
if (replacement.MatchWord == "ATIVE")
{
if (word.Length - replacement.MatchWord.Length >= stemRegion.R2)
{
word.ReplaceEnd(replacement);
}
}
else
{
word.ReplaceEnd(replacement);
}
}
}
private static void Step5(StringBuilder word, StemRegion stemRegion)
{
var length = word.Length;
if (length == 0)
{
return;
}
if (word[length - 1] == 'E' &&
(length - 1 >= stemRegion.R2 || (length - 1 >= stemRegion.R1 && !word.IsShortSyllable(length - 3))))
{
word.Length -= 1;
}
else if (length - 1 >= stemRegion.R2 && word.EndsWith("LL"))
{
word.Length -= 1;
}
}
/// <summary>
/// Determines whether the word in the string builder is a short word.
/// </summary>
/// <param name="builder">The builder to analyse.</param>
/// <param name="region">The calculated stem region for the word.</param>
/// <returns>
/// <c>true</c> if the word is a short word; otherwise, <c>false</c>.
/// </returns>
public static bool IsShortWord(this StringBuilder builder, StemRegion region)
{
return(region.R1 >= builder.Length && builder.IsShortSyllable(builder.Length - 2));
}