This markdown file is also a Unison transcript file. Transcript files are an easy way to create self-documenting Unison programs, libraries, and tutorials.
The format is just a regular markdown file with some fenced code blocks that are typechecked and elaborated by `ucm`. For example, you can call this transcript via:
This runs it on a freshly generated empty codebase. Alternately `ucm transcript.fork --codebase /path/to/code hello.md` runs the transcript on a freshly generated copy of the provided codebase. Do `ucm help` to learn more about usage.
Sometimes, you have a block which you are _expecting_ to fail, perhaps because you're illustrating how something would be a type error. Adding `:error` to the block will check for this. For instance, this program has a type error: