Module | Abbrev |
In: |
lib/abbrev.rb
|
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 input of "car" and "cone", the keys pointing to "car" would be "ca" and "car", while those pointing to "cone" would be "co", "con", and "cone".
The optional pattern parameter is a pattern or a string. Only those input strings matching the pattern, or begging the string, are considered for inclusion in the output hash
# File lib/abbrev.rb, line 44 def abbrev(words, pattern = nil) table = {} seen = Hash.new(0) if pattern.is_a?(String) pattern = /^#{Regexp.quote(pattern)}/ # regard as a prefix end words.each do |word| next if (abbrev = word).empty? while (len = abbrev.rindex(/[\w\W]\z/)) > 0 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 end words.each do |word| next if pattern && pattern !~ word table[word] = word end table end