module Abbrev
Calculates the set of unique abbreviations for a given set of strings.
require 'abbrev' require 'pp' pp Abbrev.abbrev(['ruby', 'rules'])
Generates:
{ "rub" => "ruby", "ruby" => "ruby", "rul" => "rules", "rule" => "rules", "rules" => "rules" }
It also provides an array core extension, Array#abbrev.
pp %w{summer winter}.abbrev #=> {"summe"=>"summer", "summ"=>"summer", "sum"=>"summer", "su"=>"summer", "s"=>"summer", "winte"=>"winter", "wint"=>"winter", "win"=>"winter", "wi"=>"winter", "w"=>"winter", "summer"=>"summer", "winter"=>"winter"}
Public Class Methods
Given a set of strings, calculate the set of unambiguous abbreviations for those strings, and return a hash where the keys are all the possible abbreviations and the values are the full strings.
Thus, given words
is “car” and “cone”, the keys pointing to
“car” would be “ca” and “car”, while those pointing to “cone” would be
“co”, “con”, and “cone”.
require 'abbrev' Abbrev.abbrev(['car', 'cone']) #=> {"ca"=>"car", "con"=>"cone", "co"=>"cone", "car"=>"car", "cone"=>"cone"}
The optional pattern
parameter is a pattern or a string. Only
input strings that match the pattern or start with the string are included
in the output hash.
Abbrev.abbrev(%w{car box cone}, /b/) #=> {"bo"=>"box", "b"=>"box", "box"=>"box"}
# File lib/abbrev.rb, line 67 def abbrev(words, pattern = nil) table = {} seen = Hash.new(0) if pattern.is_a?(String) pattern = /\A#{Regexp.quote(pattern)}/ # regard as a prefix end words.each do |word| next if word.empty? word.size.downto(1) { |len| abbrev = word[0...len] next if pattern && pattern !~ abbrev case seen[abbrev] += 1 when 1 table[abbrev] = word when 2 table.delete(abbrev) else break end } end words.each do |word| next if pattern && pattern !~ word table[word] = word end table end
Private Instance Methods
Given a set of strings, calculate the set of unambiguous abbreviations for those strings, and return a hash where the keys are all the possible abbreviations and the values are the full strings.
Thus, given words
is “car” and “cone”, the keys pointing to
“car” would be “ca” and “car”, while those pointing to “cone” would be
“co”, “con”, and “cone”.
require 'abbrev' Abbrev.abbrev(['car', 'cone']) #=> {"ca"=>"car", "con"=>"cone", "co"=>"cone", "car"=>"car", "cone"=>"cone"}
The optional pattern
parameter is a pattern or a string. Only
input strings that match the pattern or start with the string are included
in the output hash.
Abbrev.abbrev(%w{car box cone}, /b/) #=> {"bo"=>"box", "b"=>"box", "box"=>"box"}
# File lib/abbrev.rb, line 67 def abbrev(words, pattern = nil) table = {} seen = Hash.new(0) if pattern.is_a?(String) pattern = /\A#{Regexp.quote(pattern)}/ # regard as a prefix end words.each do |word| next if word.empty? word.size.downto(1) { |len| abbrev = word[0...len] next if pattern && pattern !~ abbrev case seen[abbrev] += 1 when 1 table[abbrev] = word when 2 table.delete(abbrev) else break end } end words.each do |word| next if pattern && pattern !~ word table[word] = word end table end