75 lines
2.6 KiB
Factor
75 lines
2.6 KiB
Factor
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IN: porter-stemmer
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USING: help.markup help.syntax ;
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HELP: step1a
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{ $values { "str" "a string" } { "newstr" "a new string" } }
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{ $description "Gets rid of plurals." }
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{ $examples
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{ $table
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{ "Input:" "Output:" }
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{ "caresses" "caress" }
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{ "ponies" "poni" }
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{ "ties" "ti" }
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{ "caress" "caress" }
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{ "cats" "cat" }
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}
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} ;
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HELP: step1b
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{ $values { "str" "a string" } { "newstr" "a new string" } }
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{ $description "Gets rid of \"-ed\" and \"-ing\" suffixes." }
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{ $examples
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{ $table
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{ "Input:" "Output:" }
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{ "feed" "feed" }
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{ "agreed" "agree" }
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{ "disabled" "disable" }
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{ "matting" "mat" }
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{ "mating" "mate" }
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{ "meeting" "meet" }
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{ "milling" "mill" }
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{ "messing" "mess" }
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{ "meetings" "meet" }
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}
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} ;
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HELP: step1c
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{ $values { "str" "a string" } { "newstr" "a new string" } }
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{ $description "Turns a terminal y to i when there is another vowel in the stem." } ;
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HELP: step2
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{ $values { "str" "a string" } { "newstr" "a new string" } }
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{ $description "Maps double suffices to single ones. so -ization maps to -ize etc. note that the string before the suffix must give positive " { $link consonant-seq } "." } ;
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HELP: step3
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{ $values { "str" "a string" } { "newstr" "a new string" } }
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{ $description "Deals with -c-, -full, -ness, etc. Similar strategy to " { $link step2 } "." } ;
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HELP: step5
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{ $values { "str" "a string" } { "newstr" "a new string" } }
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{ $description "Removes a final -e and changes a final -ll to -l if " { $link consonant-seq } " is greater than 1," } ;
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HELP: stem
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{ $values { "str" "a string" } { "newstr" "a new string" } }
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{ $description "Applies the Porter stemming algorithm to the input string." } ;
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ARTICLE: "porter-stemmer" "Porter stemming algorithm"
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"The help system uses the Porter stemming algorithm to normalize words when building the full-text search index."
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$nl
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"The Factor implementation of the algorithm is based on the Common Lisp version, which was hand-translated from ANSI C by Steven M. Haflich. The original ANSI C was written by Martin Porter."
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$nl
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"A detailed description of the algorithm, along with implementations in various languages, can be at in " { $url "http://www.tartarus.org/~martin/PorterStemmer" } "."
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$nl
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"The main word of the algorithm takes an English word as input and outputs its stem:"
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{ $subsection stem }
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"The algorithm consists of a number of steps:"
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{ $subsection step1a }
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{ $subsection step1b }
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{ $subsection step1c }
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{ $subsection step2 }
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{ $subsection step3 }
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{ $subsection step4 }
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{ $subsection step5 } ;
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ABOUT: "porter-stemmer"
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