Page:Scheme - An interpreter for extended lambda calculus.djvu/6

Sussman and Steele

December 22, 1975

5

The SCHEME Reference Manual

BLOCK

This is like the MacLISP PROGN, but arranges to evaluate its last argument without an extra net control frame (explained later), so that the last argument may involved in an iteration. Note that in SCHEME, unlike MacLISP, the body of a LAMBDA expression is not an implicit PROGN.

DO

This is like the MacLISP "new-style" DO; old-style DO is not supported.

AMAPCAR, AMAPLIST

These are like MAPCAR and MAPLIST, but they expect a SCHEME lambda closure for the first argument.

To use SCHEME, simply incant at DDT (on MIT-AI):

:LISP LIBLSP;SCHEME

which will load up the current version of SCHEME, which will announce itself and give a prompt. If you want to escape to LISP, merely hit ^G. To restart SCHEME, type (SCHEME). Sometimes one does need to use a LISP FSUBR such as UREAD; this may be accomplished by typing, for example,

(EVAL' (UREAD FOO BAR DSK LOSER))

After doing this, typing ^Q will, of course, cause SCHEME to read from the file.

This concludes the SCHEME Reference Manual.