Interpreter (Clojure does not have one, so some debug functionality is painful to implement/use), readable error messages / stack traces, resident structure edi

Interpreter (Clojure does not have one, so some debug functionality is painful to implement/use), readable error messages / stack traces, resident structure editor, clever break/trace packages, debug levels, ... were relatively sophisticated in, say, BBN Lisp. See for example BBN Lisp manual from 1971: http://www.softwarepreservation.org/projects/LISP/bbnlisp/TenexLispRef_Jul71.pdf http://www.softwarepreservation.org/projects/LISP/bbnlisp/Te... See the chapter 9 on the editor, 15 on the break package, 16 on error handling, 17 on error correction, 19 on advising, 22 on the programmer's assistant, ... In 1992 the developers of BBN Lisp / Interlisp got an ACM Software Systems award for: > ... their pioneering work in programming environments that integrated source-language debuggers, fully compatible integrated interpreter/compiler, automatic change management, structure-based editing, logging facilities, interactive graphics, and analysis/profiling tools in the Interlisp system.