Class: PostScript::Runtime

Inherits:

Object

• Object
• PostScript::Runtime

show all

Includes:

Operators

Defined in:

lib/postscript/runtime.rb

Overview

ps = PostScript::Runtime.new
ps.stack  # => []
ps.push 2 # => [2]
ps.push 2 # => [2, 2]
ps.mul    # => [4]
ps.push 2 # => [4, 2]
ps.div    # => [2]
ps.stack  # => [2]

ps = PostScript::Runtime.new
ps.stack  # => []
ps.eval "{ 2 2 mul 2 div }"
ps.stack  # => [2]

ps = PostScript::Runtime.new

# Set up the initial state
ps.push -4.0, 2.0

# Execute the "Rhomboid" spot function as defined in the PDF Spec.
ps.eval "{ abs exch abs 0.9 mul add 2 div }" # => [2.8]

Instance Method Summary (collapse)

• - (Array) eval(function)

  Evaluates the provided PostScript function and returns the stack.

• - (Object) eval_procedure(procedure) private

  Evaluates the result of a parsed PostScript procedure.

• - (Object) push(*elements)

  Pushes the provided operator onto the stack.

• - (Array) stack

  The current stack.

Methods included from Operators::Conditional

#if, #ifelse

Methods included from Operators::Boolean

#and, #eq, #ge, #gt, #le, #lt, #ne, #not, #or, #xor

Methods included from Operators::Arithmetic

#abs, #add, #atan, #bitshift, #ceiling, #cos, #cvi, #cvr, #div, #exp, #floor, #ln, #log, #mod, #mul, #neg, #round, #sin, #sqrt, #sub, #truncate

Methods included from Operators::Stack

#copy, #dup, #exch, #index, #pop, #roll

runtime.eval "{ 40 60 add 2 div }" # => [50]

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# File 'lib/postscript/runtime.rb', line 48

def eval(function)
  eval_procedure Parser.parse(function)
  stack
end

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# File 'lib/postscript/runtime.rb', line 56

def eval_procedure(procedure)
  procedure.each do |operator|
    if operator.is_a? Symbol
      send operator
    else
      push operator
    end
  end
end

runtime.push 2
runtime.eval "{ dup mult }" # => [4]

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# File 'lib/postscript/runtime.rb', line 75

def push(*elements)
  stack.push *elements
end

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# File 'lib/postscript/runtime.rb', line 80

def stack
  @stack ||= []
end