Class: ImmutableQueue

Inherits:
Object
  • Object
show all
Defined in:
lib/ImmutableQueue.rb

Class Method Summary collapse

Instance Method Summary collapse

Class Method Details

.empty ⇒ Object 



19
 
# File 'lib/ImmutableQueue.rb', line 19

def self.empty() @empty ||= ImmutableQueue.new(ImmutableStack.empty, ImmutableStack.empty) end

Instance Method Details

#pop ⇒ Object 



5
6
7
8
9
10
11
12
13
14
15
16
17
18
 
# File 'lib/ImmutableQueue.rb', line 5

def pop() f, b = front, back
if (f == ImmutableStack.empty) then
 until (b == ImmutableStack.empty) do
   (e, b = b.pop
   f = f.push(e))
 end
end
head, f = f.pop
if (f == b) then
 [head, ImmutableQueue.empty]
else
 [head, ImmutableQueue.new(f, b)]
end
end

#push(element) ⇒ Object 



2
3
4
 
# File 'lib/ImmutableQueue.rb', line 2

def push(element) b = (back or ImmutableStack.empty)
ImmutableQueue.new(front, b.push(element))
end

#push_array(arr) ⇒ Object 



20
21
22
23
 
# File 'lib/ImmutableQueue.rb', line 20

def push_array(arr) q = self
arr.each { |i| q = q.push(i) } if arr
q
end