46 lines
1.8 KiB
Factor
Executable File
46 lines
1.8 KiB
Factor
Executable File
! Copyright (C) 2008 Marc Fauconneau.
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! See http://factorcode.org/license.txt for BSD license.
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USING: arrays help.markup help.syntax io.streams.string
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sequences strings math suffix-arrays.private ;
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IN: suffix-arrays
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HELP: >suffix-array
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{ $values
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{ "seq" sequence }
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{ "array" array } }
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{ $description "Creates a suffix array from the input sequence. Suffix arrays are arrays of slices." } ;
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HELP: SA{
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{ $description "Creates a new literal suffix array at parse-time." } ;
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HELP: suffixes
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{ $values
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{ "string" string }
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{ "suffixes-seq" "a sequence of slices" } }
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{ $description "Returns a sequence of tail slices of the input string." } ;
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HELP: from-to
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{ $values
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{ "index" integer } { "begin" sequence } { "suffix-array" "a suffix-array" }
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{ "from/f" "an integer or f" } { "to/f" "an integer or f" } }
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{ $description "Finds the bounds of the suffix array that match the input sequence. A return value of " { $link f } " means that the endpoint is included." }
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{ $notes "Slices are [m,n) and we want (m,n) so we increment." } ;
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HELP: query
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{ $values
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{ "begin" sequence } { "suffix-array" "a suffix-array" }
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{ "matches" array } }
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{ $description "Returns a sequence of sequences from the suffix-array that contain the input sequence. An empty array is returned when there are no matches." } ;
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ARTICLE: "suffix-arrays" "Suffix arrays"
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"The " { $vocab-link "suffix-arrays" } " vocabulary implements the suffix array data structure for efficient lookup of subsequences. This suffix array implementation is a sorted array of suffixes. Querying it for matches uses binary search for efficiency." $nl
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"Creating new suffix arrays:"
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{ $subsections >suffix-array }
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"Literal suffix arrays:"
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{ $subsections POSTPONE: SA{ }
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"Querying suffix arrays:"
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{ $subsections query } ;
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ABOUT: "suffix-arrays"
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