Process templates When defining many similar processes, it can be useful to parameterize a single process template. This can be accomplished by defining a procedure that takes any number of arguments and returns a parameterized process. Here’s how to do this somewhat verbosely in plain Scheme:

We create a process with the make-process constructor like this: make-process name "hello" procedure ' display "hello" This creates a process with the name “hello”, which will print the string "hello" once the process is executed. The procedure field holds the Scheme code that does all the work of saying “hello”. We will talk about the procedure field a little later and show how to write code snippets in languages other than Scheme. Often we will want to refer to previously created processes later, for example to combine them in a workflow definition. To do that we need to bind the created processes to variable names. Here we bind the above process to a variable named hello: define hello make-process name "hello" procedure ' display "hello" This is a very common thing to do, so the GWL offers a shorter syntax for not only creating a process but also binding it to a variable. The following example is equivalent to the above definition:

if you’re a Lisper you may prefer to write your workflows directly in Scheme while basking in its parenthetical glow

# {

read capabilities

We borrow the term from capability-based security because these URNs can (and should) be treated as permanent and unforgable data access tokens.

update && apt in

update && apt