/// <summary>
/// Search for the longest among the following suffixes, and perform the action indicated.
/// eed eedly+
/// replace by ee if in R1
/// ed edly+ ing ingly+
/// delete if the preceding word part contains a vowel, and then
/// if the word ends at, bl or iz add e (so luxuriat -> luxuriate), or
/// if the word ends with a double remove the last letter (so hopp -> hop), or
/// if the word is short, add e (so hop -> hope)
/// </summary>
internal void StripSuffixStep1b()
{
// eed eedly+ - replace by ee if in R1
if (Stem.EndsWith("eed") ||
Stem.EndsWith("eedly"))
{
if (EndsWithAndInR1("eed") ||
EndsWithAndInR1("eedly"))
{
if (_r1.Contains(Stem.Length))
{
Stem = Stem.Substring(0, Stem.LastIndexOf("eed")) + "ee";
}
}
return;
}
// ed edly+ ing ingly+ - delete if the preceding word part contains a vowel, and then
if ((Stem.EndsWith("ed") && Stem.IndexOfAny(Vowels, 0, Stem.Length - 2) != -1) ||
(Stem.EndsWith("edly") && Stem.IndexOfAny(Vowels, 0, Stem.Length - 4) != -1) ||
(Stem.EndsWith("ing") && Stem.IndexOfAny(Vowels, 0, Stem.Length - 3) != -1) ||
(Stem.EndsWith("ingly") && Stem.IndexOfAny(Vowels, 0, Stem.Length - 5) != -1))
{
StripEnding(new string[4] {
"ed", "edly", "ing", "ingly"
});
// if the word ends at, bl or iz add e (so luxuriat -> luxuriate), or
if (Stem.EndsWith("at") ||
Stem.EndsWith("bl") ||
Stem.EndsWith("iz"))
{
Stem += "e";
return;
}
// if the word ends with a double remove the last letter (so hopp -> hop), or
string end2chars;
if (Stem.Length >= 2)
{
end2chars = Stem.Substring(Stem.Length - 2, 2);
}
else
{
return;
}
var doubleEndings = new List <string>(DoubleChars);
if (doubleEndings.Contains(end2chars))
{
Stem = Stem.Remove(Stem.Length - 1);
return;
}
// if the word is short, add e (so hop -> hope)
if (IsShortWord())
{
Stem += "e";
return;
}
}
}
/// <summary>
/// replace suffix y or Y by i if preceded by a non-vowel which is not the first letter of the word (so cry -> cri, by -> by, say -> say)
/// </summary>
internal void ReplaceSuffixStep1c()
{
//replace suffix y or Y by i if preceded by a non-vowel which is not the first letter of the word (so cry -> cri, by -> by, say -> say)
if (Stem.EndsWith("y", StringComparison.OrdinalIgnoreCase) &&
(Stem.Length > 2) &&
(Stem.IndexOfAny(Vowels, Stem.Length - 2) != Stem.Length - 2))
{
Stem = Stem.Substring(0, Stem.Length - 1) + "i";
}
}
/// <summary>
/// Define a short syllable in a word as either
/// (a) a vowel followed by a non-vowel other than w, x or Y and preceded by a non-vowel, or *
/// (b) a vowel at the beginning of the word followed by a non-vowel.
/// </summary>
/// <param name="index"></param>
/// <returns></returns>
internal bool IsShortSyllable(int index)
{
//Define a short syllable in a word as either
int vowelIndex = Stem.IndexOfAny(Vowels, index);
if (vowelIndex < 0) //Don't have a vowel
{
return(false);
}
//(a) a vowel followed by a non-vowel other than w, x or Y and preceded by a non-vowel,
if (vowelIndex > 0)
{
int expectedShortEnd = vowelIndex + 2; //Check word has room for a single non-vowel
//and so we add two because length is one more than index of last char
int nextVowelIndex = Stem.IndexOfAny(Vowels, vowelIndex + 1);
if (nextVowelIndex == expectedShortEnd ||
Stem.Length == expectedShortEnd)
{
int nonVowelIndex = Stem.IndexOfAny(NotShortSyllableNonVowels, vowelIndex + 1);
int earlyVowelIndex = Stem.IndexOfAny(Vowels, vowelIndex - 1);
return(nonVowelIndex != vowelIndex + 1 && //Check not-a-vowel (or w,x,Y) found after vowel
earlyVowelIndex == vowelIndex); // Check no vowels found in char before vowel
}
else
{
return(false);
}
}
else
//or * (b) a vowel at the beginning of the word followed by a non-vowel.
{
return(Stem.IndexOfAny(Vowels) == 0 &&
Stem.Length > 1 &&
Stem.IndexOfAny(Vowels, 1) != 1);
}
}