76 lines
1.2 KiB
Ruby
76 lines
1.2 KiB
Ruby
|
# This file contains the Ruby code from book of
|
||
|
|
# "Data Structures and Algorithms
|
||
|
|
# with Object-Oriented Design Patterns in Ruby"
|
||
|
|
# by Bruno R. Preiss.
|
||
|
|
#
|
||
|
|
# Copyright (c) 2004 by Bruno R. Preiss, P.Eng. All rights reserved.
|
||
|
|
|
||
|
|
class StackAsArray < Stack
|
||
|
|
|
||
|
|
def initialize(size = 0)
|
||
|
|
super()
|
||
|
|
@array = Array.new(size)
|
||
|
|
end
|
||
|
|
|
||
|
|
def purge
|
||
|
|
while @count > 0
|
||
|
|
@count -= 1
|
||
|
|
@array[@count] = nil
|
||
|
|
end
|
||
|
|
end
|
||
|
|
|
||
|
|
def push(obj)
|
||
|
|
raise ContainerFull if @count == @array.length
|
||
|
|
@array[@count] = obj
|
||
|
|
@count += 1
|
||
|
|
end
|
||
|
|
|
||
|
|
def pop
|
||
|
|
raise ContainerEmpty if @count == 0
|
||
|
|
@count -= 1
|
||
|
|
result = @array[@count]
|
||
|
|
@array[@count] = nil
|
||
|
|
return result
|
||
|
|
end
|
||
|
|
|
||
|
|
def top
|
||
|
|
raise ContainerEmpty if @count == 0
|
||
|
|
return @array[@count - 1]
|
||
|
|
end
|
||
|
|
|
||
|
|
def each
|
||
|
|
for i in 0 ... @count
|
||
|
|
yield @array[i]
|
||
|
|
end
|
||
|
|
end
|
||
|
|
|
||
|
|
attr_reader :array
|
||
|
|
|
||
|
|
class Iterator < Opus8::Iterator
|
||
|
|
|
||
|
|
def initialize(stack)
|
||
|
|
@stack = stack
|
||
|
|
@position = 0
|
||
|
|
end
|
||
|
|
|
||
|
|
def more?
|
||
|
|
@position < @stack.count
|
||
|
|
end
|
||
|
|
|
||
|
|
def succ
|
||
|
|
if more?
|
||
|
|
assert { more? }
|
||
|
|
result = @stack.array[@position]
|
||
|
|
@position += 1
|
||
|
|
else
|
||
|
|
result = nil
|
||
|
|
end
|
||
|
|
return result
|
||
|
|
end
|
||
|
|
end
|
||
|
|
|
||
|
|
def iter
|
||
|
|
Iterator.new(self)
|
||
|
|
end
|
||
|
|
|
||
|
|
end
|