Docs For Class PorterStemmer

Description

PHP5 Implementation of the Porter Stemmer algorithm. Certain elements were borrowed from the (broken) implementation by Jon Abernathy.

Usage:

$stem = PorterStemmer::Stem($word);

How easy is that?

Located in /lib/utilities/class.porterstemmer.php (line 21)

Variable Summary

static string $regex_consonant

static string $regex_vowel

Method Summary

static bool cvc (string $str)

static bool doubleConsonant (string $str)

static int m (string $str)

static bool replace ( &$str, string $check, string $repl, [int $m = null], string $str)

static string Stem (string $word)

static void step1ab ( $word)

static void step1c (string $word)

static void step2 (string $word)

static void step3 (string $word)

static void step4 (string $word)

static void step5 (string $word)

Variables

static string $regex_consonant = '(?:[bcdfghjklmnpqrstvwxz]|(?<=[aeiou])y|^y)' (line 27)

Regex for matching a consonant

access: private

static string $regex_vowel = '(?:[aeiou]|(?<![aeiou])y)' (line 34)

Regex for matching a vowel

access: private

Methods

static cvc (line 398)

Checks for ending CVC sequence where second C is not W, X or Y

return: Result
access: private

static bool cvc (string $str)

string $str: String to check

static doubleConsonant (line 384)

Returns true/false as to whether the given string contains two of the same consonant next to each other at the end of the string.

return: Result
access: private

static bool doubleConsonant (string $str)

string $str: String to check

static m (line 363)

What, you mean it's not obvious from the name?

m() measures the number of consonant sequences in $str. if c is a consonant sequence and v a vowel sequence, and <..> indicates arbitrary presence,

<c><v> gives 0 <c>vc<v> gives 1 <c>vcvc<v> gives 2 <c>vcvcvc<v> gives 3

return: The m count
access: private

static int m (string $str)

string $str: The string to return the m count for

static replace (line 331)

Replaces the first string with the second, at the end of the string. If third arg is given, then the preceding string must match that m count at least.

return: Whether the $check string was at the end of the $str string. True does not necessarily mean that it was replaced.
access: private

static bool replace ( &$str, string $check, string $repl, [int $m = null], string $str)

string $str: String to check
string $check: Ending to check for
string $repl: Replacement string
int $m: Optional minimum number of m() to meet
&$str

static Stem (line 43)

Stems a word. Simple huh?

return: Stemmed word
access: public

static string Stem (string $word)

string $word: Word to stem

static step1ab (line 63)

Step 1

access: private

static void step1ab ( $word)

$word

static step1c (line 111)

Step 1c

access: private

static void step1c (string $word)

string $word: Word to stem

static step2 (line 128)

Step 2

access: private

static void step2 (string $word)

string $word: Word to stem

static step3 (line 186)

Step 3

access: private

static void step3 (string $word)

string $word: String to stem

static step4 (line 224)

Step 4

access: private

static void step4 (string $word)

string $word: Word to stem

static step5 (line 295)

Step 5

access: private

static void step5 (string $word)

string $word: Word to stem