Chapter 3. Combinators

3.1. Parallel Combinator
3.2. Sequential Combinator
3.3. Pruning Combinator
3.4. Otherwise Combinator

Orc has four combinators: parallel, sequential, pruning, and otherwise. A combinator forms an expression from two component expressions. Each combinator captures a different aspect of concurrency. Syntactically, the combinators are written infix, and have lower precedence than operators or calls, but higher precedence than other expression forms.