What I've put in /Tools/T/UTILS

[Chris Riesbeck <Riesbeck at YALE>]

Here are the TLisp utility functions I've generated so far for T on
the Apollo.  None have been compiled yet, due to problems with
readmacros and macro subfunctions, but I'll get around to it Real Soon
Now.  None of this satisifies reasonable documentation standards, but
Meehan's New UCI Lisp Manual and TLISP:TLISP.DOC describe almost
everything.

Functions names are taken from TLisp, except when this led to conflict
with T.  Suggestions for new names are welcome, but less than 20
characters and 4 non-alphabetics please!

In UTILS.T:

    ADD1 and SUB1  -- until they appear in T for real
    APPEND1 -- (APPEND1 list exp) = (APPEND list (LIST exp))
    APPEND1! -- APPEND1! list exp) = (NCONC list (LIST exp))
    ATCAT -- (ATCAT -exps-) returns an atom formed by concatenating the
        print representations of all the -exps-.
    CONSP -- (CONSP exp) = (AND (LIST? exp) exp)
    := -- a macro for assignment like SET but with user hooks for new data
        structures; from Artificial Intelligence Programming
    CONS! -- (CONS! exp list) = (PUSH list exp)
    LDIFF -- (LDIFF list1 list2) returns the portion of list1 before
        list2, if list2 is a tail of list1
    LOOP -- (LOOP (INITIAL -(var val inc)-)
                  (BEFORE -exps-)
                  (WHILE exp)
                  (DO -exps-)
                  (NEXT -(var val)-)
                  (UNTIL exp)
                  (AFTER -exps-)
                  (RESULT exp)

        We really need to resolve, at least with new names, the clash
        between this LOOP and Nix's in NEWLOOP.

        The syntax of of INITIAL and NEXT has changed, and the semantics
        of INITIAL is now like MacLisp's DO.  TLISP_TO_T is aware of
        this and tries to do the safe thing when translating LOOPs.

    PRELIST -- (PRELIST list n) returns first n elements of list.
    SUFLIST -- (SUFLIST list n) drops the first n elements from list.
    MSG -- (MSG -cmds-) is a general print utility, an alternative to FORMAT

In MORE_MAPS.T:

    MAPCAN -- (MAPCAN fn -lists-) applies fn in parallel to elements of
        the lists, splices the answers together with NCONC.
    SUBSET -- (SUBSET fn -lists-) applies fn in parallel to elements of
        the lists, returns all elements of the first list for which
        fn returns true.

In FOR.T:

    FOR -- (FOR -(var IN list)-
            (WHEN -exps-)
            (DO | FILTER | SAVE | SPLICE | UNTIL | WHILE -exps-)

           This is the FOR used in CS 472.  It expands into various
           mapping functions, including MAPCAN and SUBSET.  Multiples
           expressions are implicitly BLOCKed.
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