Excellent discussion of verbosity (many keywords), orthogonality (scalar vs record expressions, calling conversations) and semantics (bizarre equality for NULL) in database query languages, focusing on SQL: https://edgedb.com/blog/we-can-do-better-than-sql/
(Uses 'design by implementation' as derogatory!)
Related Posts
I'm a huge fan of Swift's 'Error Handling Rationale' design document: https://github.com/swiftlang/swift/blob/9315673c003875158852579bd1f33480cdec5461/docs/ErrorHandlingRationale.md#fundamentals
It carefully defines terminology and compares with other languages, so you can understand Swift's position and preference in the design space.
TIL Tcl has a notion of 'safe interpreters', a mode where you can run untrusted code in a sandbox: https://www.tcl.tk/man/tcl8.4/TclCmd/safe.htm
Not many programming languages have this, but it's way safer to include in the implementation than try to build as a userland library.
What are the most popular languages that have used an AST walker for their implementation?
I know Ruby used to do this, but there must be others.
(I'm interested in the lowest PL speed that users will tolerate if you have awesome features.)