libucl

language to your needs. (Our Glorious Leader published a book in the mid-90s on doing that with Lisp, see http://www.paulgraham.com/onlisptext.html for details.) There have even been languages which are designed to be easily implemented in other languages, with whatever customizations you want. For example I personally worked with code from the 1980s that implemented a Forth variant to write financial models in. But the idea doesn't have to be literally a new language. Squint sideways at any API, object model, or library and you can see it as a language. Conceptually there is a close parallel between scripting web services, and writing a TCL script that uses prebuilt commands written in C. If you can see the parallels and see how principles from the one apply to the other, the odds are that you'll be doing both better. Whereas if you don't see it and reinvent the wheel from scratch, you're going to wind up learning lessons the hard way that were learned many, many years ago. All that said, writing and maintaining a language is significantly harder than writing business code. Therefore you'll always see rather more people writing code in languages, than writing languages to make code easy to write.

nguage to store shell history, since shell history and shell configuration are two very different jobs with different goals and trade offs. I personally would suggest a simple safe format like TOML https://github.com/toml-lang/toml for storing the history. But If you do want a single format for both configuration and history, I would implore you to pick TOML not JSON or Protocol Buffers.

ed from Python). Python sort of has some "data mode" sandboxing features, like being able to set __builtins__ when you exec/eval, but probably not enough. It didn't work well enough to prevent people from writing their own config file parser eventually. The syntax is close but not exactly what you want for some use cases.