The pattern matching translator. Its general structure is a pipeline:
Match tree ---matchPlan---> Plan ---optimize---> Plan ---emit---> Tree
The pipeline consists of three steps:
- build a plan, using methods
- optimize the plan, using methods listed in
- emit the translated tree, using methods
A plan represents the underlying decision graph. It consists of tests, let and label bindings, calls to labels and code blocks. It's represented by its own data type. Plans are optimized by inlining, hoisting, and the elimination of redundant tests and dead code.