[no subject]

[Jon L White <JONL at MIT-MC>]

    Date:  9 Nov 1980 (Sunday) 0116-EDT
    From: SHRAGE at WHARTON (Jeffrey Shrager)
    Subject: A suggested enhanced naming convention 
    How about addiing functions to replace (eventually) the MAPCAR, MAPCAN...
    .  .  .
NIL has the special form "MAPF", which even works in MacLISP;  it isn't
"autoloadable" in maclisp, but comes defined as a macro in the file
LISP:DRAMMP.FASL  (several other NIL facilities are in that file).
There may be some more general extension beyond MAPF, but for those
of you who weren't in on the discussion of two years ago, the definition 
of MAPF follows, lifted from the file MC:NIL;NEWFUN >

MAPF  -  (MAPF <result-kind> <source-kinds> <function> <as1> <as2> ... <asn>)
	This is an attempt to generalize all the various mappers by having
	the first two arguments specify the various options.  *** These first
	two items are not evaluated, but the remaining arguments are evaluated
	just as in MACLISP.
      <result-kind> must be among  
	  {LIST, NCONC, PROJ1, VECTOR, STRING, BITS, +, +$}
      <source-kinds> is a list of symbols which are source-descriptors;  a
	single symbol is treated like an infinite list of that symbol.  The
	descriptors are among 
	  {LIST, CAR, VECTOR, STRING, BITS, 1+, 1-, 1+$, 1-$, CONSTANT}
      <function> should evaluate to a  function of n arguments, and 
      <as1> ... <asn> evaluate to the argument sources for <function>
	The meaning of the  <result-kind> is:
	    LIST 	Return a LIST of all the successive results of the
			   application of <function>
	    NCONC 	Same as LIST, but as if NCONC were applied to the 
			   result, flattening it by one level.
	    PROJ1   	Return the value of <as1>, as MAPC would.
	    VECTOR 	Return a VECTOR of all the successive results of the
			   application of <function>
	    STRING 	The result of each application must be a CHARACTER - 
			   Return, then, the STRING of all those CHARACTERs.
	    BITS 	The result of each application must be either 0 or 1 - 
			   the resultant 0's and 1's are packed into a BITS.
	    +, +$	Return the numerical sum of all outputs.  "+" specifies
			  that they will all be FIXNUMs, "+" for FLONUMs.
	The meaning of the <source-kinds> is:
	    LIST 	The argument source is a list, which is successivly
			   CDR'd after successive applications.
	    CAR 	Same as LIST, except CAR of the list is given as
			   the argument to <function>
	    VECTOR 	The successive items of a VECTOR are given
	    STRING 	The successive characters of a STRING are given
	    BITS 	The successive bits (0's or 1's) of a BITS are given
	    1+, 1+$	The argument source is a FIXNUM (or FLONUM in the 
			  "1+$" case) which is successively incremented by 1.
	    1-, 1-$	Same as "1+" case, but is decremented by 1.
	    CONSTANT 	The argument source is repeatedly given, unmodified
			  as the corresponding argument to <function>; it
			  ** DOES NOT ** mean that the type of the source is
			  a constant, but only that it is not "stepped".
	 Right now, not all the combinations are worked out, but these will
	 certainly be installed initially:
	    (MAP     FOO . rst)	==>  (MAPF 'PROJ1 'LIST FOO . rst)
	    (MAPLIST FOO . rst)	==>  (MAPF 'LIST  'LIST FOO . rst)
	    (MAPC    FOO . rst)	==>  (MAPF 'PROJ1 'CAR  FOO . rst)
	    (MAPCAR  FOO . rst)	==>  (MAPF 'LIST  'CAR  FOO . rst)
	    (MAPCON  FOO . rst)	==>  (MAPF 'NCONC 'LIST FOO . rst)
	    (MAPCAN  FOO . rst)	==>  (MAPF 'NCONC 'CAR  FOO . rst)
	    (MAPVECTOR FOO . rst)   ==>  (MAPF 'VECTOR 'VECTOR FOO . rst)