Module: PostScript::Operators::Stack

Included in:

PostScript::Operators

Defined in:

lib/postscript/operators/stack.rb

Overview

Instance Method Summary (collapse)

• - (Object) copy

  Adds a copy of the last n elements on the stack.

• - (Object) dup

  Adds a duplicate copy of the top element to the end of the stack.

• - (Object) exch

  Swaps the last two elements on the stack.

• - (Object) index

  Adds a copy of the nth element on the stack.

• - (Object) pop

  Removes and returns the last element from the stack.

• - (Object) roll

  Moves the last n elements j positions on the stack, rolling over at stack boundaries.

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# File 'lib/postscript/operators/stack.rb', line 9

def copy
  n = pop

  push *stack.last(n)
end

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# File 'lib/postscript/operators/stack.rb', line 16

def dup
  push stack.last
end

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# File 'lib/postscript/operators/stack.rb', line 21

def exch
  push *(stack.pop(2).reverse)
end

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# File 'lib/postscript/operators/stack.rb', line 26

def index
  push stack[-(pop + 1)]
end

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# File 'lib/postscript/operators/stack.rb', line 33

def pop
  stack.pop
end

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# File 'lib/postscript/operators/stack.rb', line 39

def roll
  n, j = stack.pop(2)

  stack.push *stack.pop(n).rotate(-j)
end