# frozen_string_literal: true
#--
# Copyright (c) 2001,2003 Akinori MUSHA <knu@iDaemons.org>
#
# All rights reserved. You can redistribute and/or modify it under
# the same terms as Ruby.
#
# $Idaemons: /home/cvs/rb/abbrev.rb,v 1.2 2001/05/30 09:37:45 knu Exp $
# $RoughId: abbrev.rb,v 1.4 2003/10/14 19:45:42 knu Exp $
# $Id$
#++
##
# Calculates the set of unambiguous abbreviations for a given set of strings.
#
# require 'abbrev'
# require 'pp'
#
# pp Abbrev.abbrev(['ruby'])
# #=> {"ruby"=>"ruby", "rub"=>"ruby", "ru"=>"ruby", "r"=>"ruby"}
#
# pp Abbrev.abbrev(%w{ ruby rules })
#
# _Generates:_
# { "ruby" => "ruby",
# "rub" => "ruby",
# "rules" => "rules",
# "rule" => "rules",
# "rul" => "rules" }
#
# It also provides an array core extension, Array#abbrev.
#
# pp %w{ summer winter }.abbrev
#
# _Generates:_
# { "summer" => "summer",
# "summe" => "summer",
# "summ" => "summer",
# "sum" => "summer",
# "su" => "summer",
# "s" => "summer",
# "winter" => "winter",
# "winte" => "winter",
# "wint" => "winter",
# "win" => "winter",
# "wi" => "winter",
# "w" => "winter" }
module Abbrev
# 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(%w{ 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 crab}, /b/)
# #=> {"box"=>"box", "bo"=>"box", "b"=>"box", "crab" => "crab"}
#
# Abbrev.abbrev(%w{car box cone}, 'ca')
# #=> {"car"=>"car", "ca"=>"car"}
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
module_function :abbrev
end
class Array
# Calculates the set of unambiguous abbreviations for the strings in +self+.
#
# require 'abbrev'
# %w{ car cone }.abbrev
# #=> {"car"=>"car", "ca"=>"car", "cone"=>"cone", "con"=>"cone", "co"=>"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.
#
# %w{ fast boat day }.abbrev(/^.a/)
# #=> {"fast"=>"fast", "fas"=>"fast", "fa"=>"fast", "day"=>"day", "da"=>"day"}
#
# Abbrev.abbrev(%w{car box cone}, "ca")
# #=> {"car"=>"car", "ca"=>"car"}
#
# See also Abbrev.abbrev
def abbrev(pattern = nil)
Abbrev::abbrev(self, pattern)
end
end