pan/functions Template

Several pan programming patterns or idioms occur frequently in machine configurations. The functions defined in the "pan/functions" template provide shortcuts to using those idioms. To access the functions, the template must be included in the machine configuration:

  include { 'pan/functions' };

After this is included, any of the defined functions can be used from within DML blocks.

'self' Utility Functions

Often one want to add elements to a resource (list or hash) incrementally with a sequence of assignment statements. Those assignment statements usually being in different templates. The following functions provide simple mechanisms to do so.

"""push(element...) """ This function will return a copy of self with the given value(s) appended to the end. If self is undefined, the function will create a new list with the arguments and return that. An example is

  '/mylist' = push('a');
  '/mylist' = push('b');

The final value for '/mylist' will be a two-element list containing 'a' and 'b'.

Be careful, however, because the value of self is not directly modified by the push() function. This means that the following:

  '/mylist' = {
    push('a');
    push('b');
  };

will leave '/mylist' with the one-element list 'b'.

'object' Utility Functions