scope-capture VS plumbing

Awesome tools.

Personally I can't imagine coding in clojure without scope capture

https://github.com/vvvvalvalval/scope-capture

I haven't tried it myself. I generally just use truss for runtime constraint checking. I use a modified version that integrates scope-capture. And malli validation for more complex cases, but I try to limit that. For me it is better to validate individual attributes as needed, vs validating an entire "type"/collection of attributes. So each function only cares about the attributes that it needs, and validates only as needed.

Use scope-capture to observe the actual data flowing through the system

Scope capture library https://github.com/vvvvalvalval/scope-capture automates this approach.

Is anyone aware of any prior art along the lines of this? I've seen scope-capture but it's more about instrumenting existing programs than writing new ones interactively.

I am not advocating against the use of a compiler. I am going to illustrate how to reproduce the scope of a program and replay it in the REPL as it is done for instance in Clojure with scope-capture. In some use cases, I find this approach is simpler than using a debugger. This approach is possible only because the data is immutable.

This library https://github.com/plumatic/plumbing, a predecessor of spec, has variants of defn and fn that allow you to specify the schema inline, sort of similar to type hints.

This reminds me a bit of a Clojure library called Plumbing (formerly Graph): https://github.com/plumatic/plumbing. It also let you create a DAG for structured computation. It was used for a web service, at that time.