import ast
def process(node):
  pass
 
def processComprehension( node, dest, expr ):
  #ast.diag( node )
  #ast.diag( node.assign )
  #ast.diag( node.list )
  #ast.diag( node.ifs )

  forCondition = ast.nextLabel()
  afterFor = ast.nextLabel()
  iterator = ast.nextPRegister()
  list = ast.nextPRegister()
  iteratorVariable = ast.nextPRegister()

  ast.outputInBlock(".include \"iterator.pasm\"")
  ast.outputInBlock("%s = %s" % ( list, ast.evaluate( node.list ) ) )
  ast.outputInBlock("new %s, .Iterator, %s" % ( iterator, list ) )
  ast.outputInBlock("set %s, .ITERATE_FROM_START" % ( iterator ) )
  ast.outputLabel( forCondition )
  ast.outputInBlock( "unless %s, %s" % ( iterator, afterFor ) )

  ast.outputInBlock("shift %s, %s" % ( iteratorVariable, iterator ) )
  ast.outputInBlock("%s = %s" % ( ast.evaluate( node.assign ), iteratorVariable ) )

  #body
  #ast.evaluate( node.body )
  if len( node.ifs ):
    for x in node.ifs:
      ast.ListCompIf.processComprehension( x, dest, expr)
  else:
    ast.outputInBlock( "%s.append( %s, %s )" % ( dest, dest, ast.evaluate( expr ) ) )

  ast.outputInBlock( "branch %s" % ( forCondition ) )
  ast.outputLabel( afterFor )