ch2_3_predic
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Predicates
Simple function that return T or NIL.
EQ
Tests if to arguments are the same symbol, accepts only symbols or NIL.
>(eq 'pi 'user::pi) T >(eq 'nil ()) ; NIL, 'NIL, () and '() are all EQ T
EQUAL
Tests if two things are the same, is case and type senstive.
NOT
Logical not. Accepts single argument.
>(not 13) NIL >(not '()) T
ATOM
Tests if the argument isa an atom.
>(atom 13) T >(atom nil) ; NIL is an atom (and list) T >(atom '()) ; this is still NIL T >(atom '(a b)) ; this is list NIL
CONSP
Tests if the argument is a cons cell.
>(consp '()) ; NIL is not cons NIL >(consp '(a b)) T
LISTP
Tests if the argument is a proper list. Proper list means list ending with NIL in the cdr of the last cons cell.
>(listp nil) ; NIL is a list (and atom) T >(listp '(a b)) T >(listp (cons 'a 'b)) ; this is conscell with B in cdr NIL
SYMBOLP
stringp
numberp
integerp
zerop
Oddp
Evenp
functionp
packagep
Boundp
fboundp
SPECIAL-OPERATOR-P
ch2_3_predic.1619166989.txt.gz · Last modified: 2021/04/23 02:36 by admin