class Hashie::Rash
Rash
is a Hash
whose keys can be Regexps, or Ranges, which will match many input keys.
A good use case for this class is routing URLs in a web framework. The Rash’s keys match URL patterns, and the values specify actions which can handle the URL. When the Rash’s value is proc, the proc will be automatically called with the regexp’s matched groups as block arguments.
Usage example:
greeting = Hashie::Rash.new( /^Mr./ => "Hello sir!", /^Mrs./ => "Evening, madame." ) greeting["Mr. Steve Austin"] #=> "Hello sir!" greeting["Mrs. Steve Austin"] #=> "Evening, madame."
Note: The Rash
is automatically optimized every 500 accesses
(Regexps get sorted by how often they get matched). If this is too low or too high, you can tune it by setting: `rash.optimize_every = n`
Attributes
Public Class Methods
Source
# File lib/hashie/rash.rb, line 26 def initialize(initial = {}) @hash = {} @regexes = [] @ranges = [] @regex_counts = Hash.new(0) @optimize_every = 500 @lookups = 0 update(initial) end
Public Instance Methods
Source
# File lib/hashie/rash.rb, line 59 def [](key) all(key).first end
Return the first thing that matches the key.
Source
# File lib/hashie/rash.rb, line 45 def []=(key, value) case key when Regexp # key = normalize_regex(key) # this used to just do: /#{regexp}/ @regexes << key when Range @ranges << key end @hash[key] = value end
Source
# File lib/hashie/rash.rb, line 88 def all(query) return to_enum(:all, query) unless block_given? if @hash.include? query yield @hash[query] return end case query when String optimize_if_necessary! # see if any of the regexps match the string @regexes.each do |regex| match = regex.match(query) next unless match @regex_counts[regex] += 1 value = @hash[regex] if value.respond_to? :call yield value.call(match) else yield value end end when Numeric # see if any of the ranges match the integer @ranges.each do |range| yield @hash[range] if range.cover? query end when Regexp # Reverse operation: `rash[/regexp/]` returns all string keys matching the regexp @hash.each do |key, val| yield val if key.is_a?(String) && query =~ key end end end
Return everything that matches the query.
Source
# File lib/hashie/rash.rb, line 66 def fetch(*args) raise ArgumentError, "Expected 1-2 arguments, got #{args.length}" \ unless (1..2).cover?(args.length) key, default = args all(key) do |value| return value end if block_given? yield key elsif default default else raise KeyError, "key not found: #{key.inspect}" end end
Raise (or yield) unless something matches the key.
Source
# File lib/hashie/rash.rb, line 127 def method_missing(*args, &block) @hash.send(*args, &block) || super end
Calls superclass method
Source
# File lib/hashie/rash.rb, line 131 def respond_to_missing?(method_name, _include_private = false) @hash.respond_to?(method_name) end
Source
# File lib/hashie/rash.rb, line 37 def update(other) other.each do |key, value| self[key] = value end self end
Private Instance Methods
Source
# File lib/hashie/rash.rb, line 137 def optimize_if_necessary! return unless (@lookups += 1) >= @optimize_every @regexes = @regexes.sort_by { |regex| -@regex_counts[regex] } @lookups = 0 end