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 don'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

You can use # to set internal sort order.
#<< takes a two element [k,v] array and inserts.
Use ::auto which creates Dictionay sub-entries as needed.
And ::alpha which creates a new Dictionary sorted by key.

Public Class Methods

[](*args) click to toggle source

    # File lib/more/facets/dictionary.rb, line 74
74:     def [](*args)
75:       hsh = new
76:       if Hash === args[0]
77:         hsh.replace(args[0])
78:       elsif (args.size % 2) != 0
79:         raise ArgumentError, "odd number of elements for Hash"
80:       else
81:         while !args.empty?
82:           hsh[args.shift] = args.shift
83:         end
84:       end
85:       hsh
86:     end

alpha(*args, &block) click to toggle source

Alternate to # 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/more/facets/dictionary.rb, line 106
106:     def alpha(*args, &block)
107:       new(*args, &block).order_by_key
108:     end

auto(*args) click to toggle source

Alternate to # which auto-creates sub-dictionaries as needed.

  d = Dictionary.auto
  d["a"]["b"]["c"] = "abc"  #=> { "a"=>{"b"=>{"c"=>"abc"}}}

     # File lib/more/facets/dictionary.rb, line 115
115:     def auto(*args)
116:       #AutoDictionary.new(*args)
117:       leet = lambda { |hsh, key| hsh[key] = new(&leet) }
118:       new(*args, &leet)
119:     end

new(*args, &blk) click to toggle source

New Dictiionary.

     # File lib/more/facets/dictionary.rb, line 124
124:   def initialize(*args, &blk)
125:     @order = []
126:     @order_by = nil
127:     if blk
128:       dict = self                                  # This ensure autmatic key entry effect the
129:       oblk = lambda{ |hsh, key| blk[dict,key] }    # dictionary rather then just the interal hash.
130:       @hash = Hash.new(*args, &oblk)
131:     else
132:       @hash = Hash.new(*args)
133:     end
134:   end

new_by(*args, &blk) click to toggle source

Like # but the block sets the order.

    # File lib/more/facets/dictionary.rb, line 90
90:     def new_by(*args, &blk)
91:       new(*args).order_by(&blk)
92:     end

Public Instance Methods

<<(kv) click to toggle source

     # File lib/more/facets/dictionary.rb, line 327
327:   def <<(kv)
328:     push(*kv)
329:   end

==(hsh2) click to toggle source

def ==( hsh2 )

  return false if @order != hsh2.order
  super hsh2

end

     # File lib/more/facets/dictionary.rb, line 201
201:   def ==(hsh2)
202:     if hsh2.is_a?( Dictionary )
203:       @order == hsh2.order &&
204:       @hash  == hsh2.instance_variable_get("@hash")
205:     else
206:       false
207:     end
208:   end

[](k) click to toggle source

     # File lib/more/facets/dictionary.rb, line 210
210:   def [] k
211:     @hash[ k ]
212:   end

[]=(k, i=nil, v=nil) click to toggle source

Store operator.

  h[key] = value

Or with additional index.

 h[key,index] = value

     # File lib/more/facets/dictionary.rb, line 226
226:   def []=(k, i=nil, v=nil)
227:     if v
228:       insert(i,k,v)
229:     else
230:       store(k,i)
231:     end
232:   end

clear() click to toggle source

     # File lib/more/facets/dictionary.rb, line 244
244:   def clear
245:     @order = []
246:     @hash.clear
247:   end

delete( key ) click to toggle source

     # File lib/more/facets/dictionary.rb, line 249
249:   def delete( key )
250:     @order.delete( key )
251:     @hash.delete( key )
252:   end

delete_if() click to toggle source

     # File lib/more/facets/dictionary.rb, line 270
270:   def delete_if
271:     order.clone.each { |k| delete k if yield(k,@hash[k]) }
272:     self
273:   end

dup() click to toggle source

     # File lib/more/facets/dictionary.rb, line 352
352:   def dup
353:     a = []
354:     each{ |k,v| a << k; a << v }
355:     self.class[*a]
356:   end

each() click to toggle source

     # File lib/more/facets/dictionary.rb, line 264
264:   def each
265:     order.each { |k| yield( k,@hash[k] ) }
266:     self
267:   end

Also aliased as: each_pair

each_key() click to toggle source

     # File lib/more/facets/dictionary.rb, line 254
254:   def each_key
255:     order.each { |k| yield( k ) }
256:     self
257:   end

each_pair() click to toggle source

Alias for: each

each_value() click to toggle source

     # File lib/more/facets/dictionary.rb, line 259
259:   def each_value
260:     order.each { |k| yield( @hash[k] ) }
261:     self
262:   end

empty?() click to toggle source

     # File lib/more/facets/dictionary.rb, line 401
401:   def empty?
402:     @hash.empty?
403:   end

fetch(k, *a, &b) click to toggle source

     # File lib/more/facets/dictionary.rb, line 214
214:   def fetch(k, *a, &b)
215:     @hash.fetch(k, *a, &b)
216:   end

first(x=nil) click to toggle source

     # File lib/more/facets/dictionary.rb, line 385
385:   def first(x=nil)
386:     return @hash[order.first] unless x
387:     order.first(x).collect { |k| @hash[k] }
388:   end

has_key?(key) click to toggle source

     # File lib/more/facets/dictionary.rb, line 405
405:   def has_key?(key)
406:     @hash.has_key?(key)
407:   end

insert( i,k,v ) click to toggle source

     # File lib/more/facets/dictionary.rb, line 234
234:   def insert( i,k,v )
235:     @order.insert( i,k )
236:     @hash.store( k,v )
237:   end

inspect() click to toggle source

     # File lib/more/facets/dictionary.rb, line 346
346:   def inspect
347:     ary = []
348:     each {|k,v| ary << k.inspect + "=>" + v.inspect}
349:     '{' + ary.join(", ") + '}'
350:   end

invert() click to toggle source

     # File lib/more/facets/dictionary.rb, line 285
285:   def invert
286:     hsh2 = self.class.new
287:     order.each { |k| hsh2[@hash[k]] = k }
288:     hsh2
289:   end

key?(key) click to toggle source

     # File lib/more/facets/dictionary.rb, line 409
409:   def key?(key)
410:     @hash.key?(key)
411:   end

keys() click to toggle source

     # File lib/more/facets/dictionary.rb, line 281
281:   def keys
282:     order
283:   end

last(x=nil) click to toggle source

     # File lib/more/facets/dictionary.rb, line 391
391:   def last(x=nil)
392:     return @hash[order.last] unless x
393:     order.last(x).collect { |k| @hash[k] }
394:   end

length() click to toggle source

     # File lib/more/facets/dictionary.rb, line 396
396:   def length
397:     @order.length
398:   end

Also aliased as: size

merge( hsh2 ) click to toggle source

     # File lib/more/facets/dictionary.rb, line 365
365:   def merge( hsh2 )
366:     self.dup.update(hsh2)
367:   end

merge!( hsh2 ) click to toggle source

Alias for: update

order() click to toggle source

     # File lib/more/facets/dictionary.rb, line 136
136:   def order
137:     reorder if @order_by
138:     @order
139:   end

order_by( &block ) click to toggle source

Keep dictionary sorted by a specific sort order.

     # File lib/more/facets/dictionary.rb, line 143
143:   def order_by( &block )
144:     @order_by = block
145:     order
146:     self
147:   end

order_by_key() click to toggle source

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/more/facets/dictionary.rb, line 163
163:   def order_by_key
164:     @order_by = lambda { |k,v| k }
165:     order
166:     self
167:   end

order_by_value() click to toggle source

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/more/facets/dictionary.rb, line 181
181:   def order_by_value
182:     @order_by = lambda { |k,v| v }
183:     order
184:     self
185:   end

pop() click to toggle source

     # File lib/more/facets/dictionary.rb, line 341
341:   def pop
342:     key = order.last
343:     key ? [key,delete(key)] : nil
344:   end

push( k,v ) click to toggle source

     # File lib/more/facets/dictionary.rb, line 331
331:   def push( k,v )
332:     unless @hash.include?( k )
333:       @order.push( k )
334:       @hash.store( k,v )
335:       true
336:     else
337:       false
338:     end
339:   end

reject(&block) click to toggle source

     # File lib/more/facets/dictionary.rb, line 291
291:   def reject(&block)
292:     self.dup.delete_if(&block)
293:   end

reject!( &block ) click to toggle source

     # File lib/more/facets/dictionary.rb, line 295
295:   def reject!( &block )
296:     hsh2 = reject(&block)
297:     self == hsh2 ? nil : hsh2
298:   end

reorder() click to toggle source

     # File lib/more/facets/dictionary.rb, line 188
188:   def reorder
189:     if @order_by
190:       assoc = @order.collect{ |k| [k,@hash[k]] }.sort_by(&@order_by)
191:       @order = assoc.collect{ |k,v| k }
192:     end
193:     @order
194:   end

replace(hsh2) click to toggle source

     # File lib/more/facets/dictionary.rb, line 300
300:   def replace(hsh2)
301:     case hsh2
302:     when Hash
303:       @order = hsh2.keys
304:       @hash  = hsh2
305:     else
306:       @order = hsh2.order
307:       @hash  = hsh2.hash
308:     end
309:     reorder
310:   end

reverse() click to toggle source

     # File lib/more/facets/dictionary.rb, line 380
380:   def reverse
381:     dup.reverse!
382:   end

reverse!() click to toggle source

     # File lib/more/facets/dictionary.rb, line 375
375:   def reverse!
376:     @order.reverse!
377:     self
378:   end

select() click to toggle source

     # File lib/more/facets/dictionary.rb, line 369
369:   def select
370:     ary = []
371:     each { |k,v| ary << [k,v] if yield k,v }
372:     ary
373:   end

shift() click to toggle source

     # File lib/more/facets/dictionary.rb, line 312
312:   def shift
313:     key = order.first
314:     key ? [key,delete(key)] : super
315:   end

size() click to toggle source

Alias for: length

store( a,b ) click to toggle source

     # File lib/more/facets/dictionary.rb, line 239
239:   def store( a,b )
240:     @order.push( a ) unless @hash.has_key?( a )
241:     @hash.store( a,b )
242:   end

to_a() click to toggle source

     # File lib/more/facets/dictionary.rb, line 413
413:   def to_a
414:     ary = []
415:     each { |k,v| ary << [k,v] }
416:     ary
417:   end

to_h() click to toggle source

     # File lib/more/facets/dictionary.rb, line 427
427:   def to_h
428:     @hash.dup
429:   end

to_hash() click to toggle source

     # File lib/more/facets/dictionary.rb, line 423
423:   def to_hash
424:     @hash.dup
425:   end

to_s() click to toggle source

     # File lib/more/facets/dictionary.rb, line 419
419:   def to_s
420:     self.to_a.to_s
421:   end

unshift( k,v ) click to toggle source

     # File lib/more/facets/dictionary.rb, line 317
317:   def unshift( k,v )
318:     unless @hash.include?( k )
319:       @order.unshift( k )
320:       @hash.store( k,v )
321:       true
322:     else
323:       false
324:     end
325:   end

update( hsh2 ) click to toggle source

     # File lib/more/facets/dictionary.rb, line 358
358:   def update( hsh2 )
359:     hsh2.each { |k,v| self[k] = v }
360:     reorder
361:     self
362:   end

Also aliased as: merge!

values() click to toggle source

     # File lib/more/facets/dictionary.rb, line 275
275:   def values
276:     ary = []
277:     order.each { |k| ary.push @hash[k] }
278:     ary
279:   end

Home Classes Methods

In Files

Parent

Methods

Included Modules

Class Index

Dictionary

Dictionary

Usage

Usage Notes

Public Class Methods

Public Instance Methods