The language pattern occurs quite frequently in many domains. Unfortunately, I have so far only seen half-assed interpreters. At best, people did a shallow embe

The language pattern occurs quite frequently in many domains. Unfortunately, I have so far only seen half-assed interpreters. At best, people did a shallow embedding (interpreter) of their DSL. No one ever did a true compiler. I think the reason for this can be found in the ideal encoding of the input language: In its most concise formulation, a language is a recursive algebraic datatypes. Handling of that input requires a recursive algorithm that deals with all corner cases. Engineers I worked with tend to not see their input language as an ADT, though. They focus on some particular use cases and if there is a specification it is often too large and yet incomplete. But on top of that comes the hesitation to implement a complete algorithm. Nearly every time, some "corner case" is ignored because "nobody uses it" and we end up with an implementation that is factually incorrect and incomplete.