APLBOL(ID:4376/apl011)

APL written in SNOBOL 

SNOBOL with APL features

Leichter Brandeis 1975
Related languages
APL => APLBOL   Subset
SNOBOL => APLBOL   Augmentation of
References:
  • Leichter, Jerry. 1976. APLBOL. (Unpublished technical report.) Waltham, MA: Brandeis University, Mathematics Department. view details
    Resources
    • Newsgroup posting by Jerry Lechter to COMP.LANG.ICON
    • Newsgroup posting by Jerry Lechter to COMP.LANG.ICON
      It's also possible to write debuggers which allow you to type in SNOBOL code
      on the fly and evaluate it.  I've seen a number of tools of this general sort.
      I took it to its logical extreme in a system I wrote years ago called APLBOL.
      APLBOL, which was built on SITBOL on PDP-10's and -20's, had the same user
      interface as APL, although the language was (of course) SNOBOL.  The only
      "fixed" code in the system was the APLBOL implementation; every line of code
      a user wrote was actually "established" by CODE().  Worked quite nicely, and
      it was great for quick and easy development.  (Had some amazing hacks in it
      to make it work, though.  Unfortunately, some of the central hacks were
      based on SITBOL-specific extensions, so it won't work on any other SNOBOL.)

      Now, you could argue that APLBOL wasn't SELF-modifying - the APLBOL code
      modified the user code, not itself, and the user code did NOT modify itself.
      But that's just the point:  Self-modification if uncontrolled is a disaster;
      but self-modification fit into a rational scheme is extremely useful. (Actu-
      ally, it WAS possible to modify the APLBOL code, if you knew how and ignored
      the "don't do this or you may be screwed" rules, which basically reserved
      a certain name space to internal routines.  This could be VERY handy for
      debugging, but was otherwise not recommended.  However, there were a couple
      of "documented" hooks so that, for example, you could insert a pre-processor
      that would muck with code before it was handed to CODE().)
      external link