This seems similar to my protostrings library [1] which I wrote years ago and mostly forgot about till now. 1. https://protostrings.readthedocs.io/en/latest/in

This seems similar to my protostrings library [1] which I wrote years ago and mostly forgot about till now. 1. https://protostrings.readthedocs.io/en/latest/index.xhtml https://protostrings.readthedocs.io/en/latest/index.xhtml iirc I wanted to encode state in a recursive-descent parser without additional complexity to the parser. Similar in purpose not design; protostrings provides lazy and context-sensitive strings from the bottom up rather than this top-down template-style proposal, which I feel addresses most of the concerns here.