class Dictionary
Dictionary¶ ↑
The Dictionary class is a Hash that preserves order. So it has some array-like extensions also. By defualt a Dictionary object preserves insertion order, but any order can be specified including alphabetical key order.
Usage¶ ↑
Just require this file and use Dictionary instead of Hash.
# You can do simply hsh = Dictionary.new hsh['z'] = 1 hsh['a'] = 2 hsh['c'] = 3 p hsh.keys #=> ['z','a','c'] # or using Dictionary[] method hsh = Dictionary['z', 1, 'a', 2, 'c', 3] p hsh.keys #=> ['z','a','c'] # but this doesn't preserve order hsh = Dictionary['z'=>1, 'a'=>2, 'c'=>3] p hsh.keys #=> ['a','c','z'] # Dictionary has useful extensions: push, pop and unshift p hsh.push('to_end', 15) #=> true, key added p hsh.push('to_end', 30) #=> false, already - nothing happen p hsh.unshift('to_begin', 50) #=> true, key added p hsh.unshift('to_begin', 60) #=> false, already - nothing happen p hsh.keys #=> ["to_begin", "a", "c", "z", "to_end"] p hsh.pop #=> ["to_end", 15], if nothing remains, return nil p hsh.keys #=> ["to_begin", "a", "c", "z"] p hsh.shift #=> ["to_begin", 30], if nothing remains, return nil
Usage Notes¶ ↑
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You can use order_by to set internal sort order.
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<< takes a two element [k,v] array and inserts.
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Use ::auto which creates Dictionay sub-entries as needed.
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And ::alpha which creates a new Dictionary sorted by key.
Public Class Methods
# File lib/extlib/dictionary.rb, line 88 def [](*args) hsh = new if Hash === args[0] hsh.replace(args[0]) elsif (args.size % 2) != 0 raise ArgumentError, "odd number of elements for Hash" else while !args.empty? hsh[args.shift] = args.shift end end hsh end
Alternate to new which creates a dictionary sorted by key.
d = Dictionary.alpha d["z"] = 1 d["y"] = 2 d["x"] = 3 d #=> {"x"=>3,"y"=>2,"z"=>2}
This is equivalent to:
Dictionary.new.order_by { |key,value| key }
# File lib/extlib/dictionary.rb, line 119 def alpha(*args, &block) new(*args, &block).order_by_key end
Alternate to new which auto-creates sub-dictionaries as needed.
d = Dictionary.auto d["a"]["b"]["c"] = "abc" #=> { "a"=>{"b"=>{"c"=>"abc"}}}
# File lib/extlib/dictionary.rb, line 128 def auto(*args) #AutoDictionary.new(*args) leet = lambda { |hsh, key| hsh[key] = new(&leet) } new(*args, &leet) end
New Dictiionary.
# File lib/extlib/dictionary.rb, line 136 def initialize(*args, &blk) @order = [] @order_by = nil if blk dict = self # This ensure autmatic key entry effect the oblk = lambda{ |hsh, key| blk[dict,key] } # dictionary rather then just the interal hash. @hash = Hash.new(*args, &oblk) else @hash = Hash.new(*args) end end
Like new but the block sets the order.
# File lib/extlib/dictionary.rb, line 104 def new_by(*args, &blk) new(*args).order_by(&blk) end
Public Instance Methods
# File lib/extlib/dictionary.rb, line 323 def <<(kv) push( *kv ) end
# File lib/extlib/dictionary.rb, line 205 def ==(hsh2) if hsh2.is_a?( Dictionary ) @order == hsh2.order && @hash == hsh2.instance_variable_get("@hash") else false end end
# File lib/extlib/dictionary.rb, line 214 def [] k @hash[ k ] end
Store operator.
h[key] = value
Or with additional index.
h[key,index] = value
# File lib/extlib/dictionary.rb, line 229 def []=(k, i=nil, v=nil) if v insert(i,k,v) else store(k,i) end end
# File lib/extlib/dictionary.rb, line 247 def clear @order = [] @hash.clear end
# File lib/extlib/dictionary.rb, line 252 def delete( key ) @order.delete( key ) @hash.delete( key ) end
# File lib/extlib/dictionary.rb, line 273 def delete_if order.clone.each { |k| delete k if yield(k,@hash[k]) } self end
# File lib/extlib/dictionary.rb, line 348 def dup a = [] each{ |k,v| a << k; a << v } self.class[*a] end
# File lib/extlib/dictionary.rb, line 267 def each order.each { |k| yield( k,@hash[k] ) } self end
# File lib/extlib/dictionary.rb, line 257 def each_key order.each { |k| yield( k ) } self end
# File lib/extlib/dictionary.rb, line 262 def each_value order.each { |k| yield( @hash[k] ) } self end
# File lib/extlib/dictionary.rb, line 393 def empty? @hash.empty? end
# File lib/extlib/dictionary.rb, line 218 def fetch(k, *a, &b) @hash.fetch(k, *a, &b) end
# File lib/extlib/dictionary.rb, line 380 def first @hash[order.first] end
# File lib/extlib/dictionary.rb, line 397 def has_key?(key) @hash.has_key?(key) end
# File lib/extlib/dictionary.rb, line 237 def insert( i,k,v ) @order.insert( i,k ) @hash.store( k,v ) end
# File lib/extlib/dictionary.rb, line 342 def inspect ary = [] each {|k,v| ary << k.inspect + "=>" + v.inspect} '{' + ary.join(", ") + '}' end
# File lib/extlib/dictionary.rb, line 288 def invert hsh2 = self.class.new order.each { |k| hsh2[@hash[k]] = k } hsh2 end
# File lib/extlib/dictionary.rb, line 401 def key?(key) @hash.key?(key) end
# File lib/extlib/dictionary.rb, line 284 def keys order end
# File lib/extlib/dictionary.rb, line 384 def last @hash[order.last] end
# File lib/extlib/dictionary.rb, line 388 def length @order.length end
# File lib/extlib/dictionary.rb, line 361 def merge( hsh2 ) self.dup.update(hsh2) end
# File lib/extlib/dictionary.rb, line 148 def order reorder if @order_by @order end
Keep dictionary sorted by a specific sort order.
# File lib/extlib/dictionary.rb, line 154 def order_by( &block ) @order_by = block order self end
Keep dictionary sorted by key.
d = Dictionary.new.order_by_key d["z"] = 1 d["y"] = 2 d["x"] = 3 d #=> {"x"=>3,"y"=>2,"z"=>2}
This is equivalent to:
Dictionary.new.order_by { |key,value| key }
The initializer Dictionary#alpha also provides this.
# File lib/extlib/dictionary.rb, line 173 def order_by_key @order_by = lambda { |k,v| k } order self end
Keep dictionary sorted by value.
d = Dictionary.new.order_by_value d["z"] = 1 d["y"] = 2 d["x"] = 3 d #=> {"x"=>3,"y"=>2,"z"=>2}
This is equivalent to:
Dictionary.new.order_by { |key,value| value }
# File lib/extlib/dictionary.rb, line 190 def order_by_value @order_by = lambda { |k,v| v } order self end
# File lib/extlib/dictionary.rb, line 337 def pop key = order.last key ? [key,delete(key)] : nil end
# File lib/extlib/dictionary.rb, line 327 def push( k,v ) unless @hash.include?( k ) @order.push( k ) @hash.store( k,v ) true else false end end
# File lib/extlib/dictionary.rb, line 294 def reject( &block ) self.dup.delete_if(&block) end
# File lib/extlib/dictionary.rb, line 298 def reject!( &block ) hsh2 = reject(&block) self == hsh2 ? nil : hsh2 end
# File lib/extlib/dictionary.rb, line 197 def reorder if @order_by assoc = @order.collect{ |k| [k,@hash[k]] }.sort_by(&@order_by) @order = assoc.collect{ |k,v| k } end @order end
# File lib/extlib/dictionary.rb, line 303 def replace( hsh2 ) @order = hsh2.order @hash = hsh2.hash end
# File lib/extlib/dictionary.rb, line 376 def reverse dup.reverse! end
# File lib/extlib/dictionary.rb, line 371 def reverse! @order.reverse! self end
# File lib/extlib/dictionary.rb, line 365 def select ary = [] each { |k,v| ary << [k,v] if yield k,v } ary end
# File lib/extlib/dictionary.rb, line 308 def shift key = order.first key ? [key,delete(key)] : super end
# File lib/extlib/dictionary.rb, line 242 def store( a,b ) @order.push( a ) unless @hash.has_key?( a ) @hash.store( a,b ) end
# File lib/extlib/dictionary.rb, line 405 def to_a ary = [] each { |k,v| ary << [k,v] } ary end
# File lib/extlib/dictionary.rb, line 430 def to_h @hash.dup end
# File lib/extlib/dictionary.rb, line 426 def to_hash @hash.dup end
# File lib/extlib/dictionary.rb, line 411 def to_json buf = "[" map do |k,v| buf << k.to_json buf << ", " buf << v.to_json end.join(", ") buf << "]" buf end
# File lib/extlib/dictionary.rb, line 422 def to_s self.to_a.to_s end
# File lib/extlib/dictionary.rb, line 313 def unshift( k,v ) unless @hash.include?( k ) @order.unshift( k ) @hash.store( k,v ) true else false end end
# File lib/extlib/dictionary.rb, line 354 def update( hsh2 ) hsh2.each { |k,v| self[k] = v } reorder self end
# File lib/extlib/dictionary.rb, line 278 def values ary = [] order.each { |k| ary.push @hash[k] } ary end