id validator mark

id_validator_mark

id_validator: mark
  propagation: propagation_types.package | propagation_types.viral
  
  # Override mark.infect() -- define what parts of code should acquire this mark
  # automatically. Return a list of (site, mark_type) tuples.
  def infect(site):
    infected = []
    for module in site.package.modules:
      for function in module.functions:
        for param in function.parameters:
          if param.datatype == typeof(str) and param.name == "id":
            infected.append(param, mark_types.implicit_affirmative)
    return infected

  def can_bind(site):
    if site.type != site_types.package:
      return "Must be placed on a package."
      
  # At compile time, generate appropriate preconditions
  # in the code for the function that uses a marked parameter
  def generate(site):
    insert_point = site.function.body.statements[0]
    generated = "precondition(%s)\nn = len(%s)" % site.name
    generated += "precondition(s >= 20 and s <= 40)" % site.name
    return insert_point, generated