LispForum

HI I have problems with keyword and rest arguments mixing… For example, if we have the following func: (defun arguments (&rest args &key (a 4) (b 5) (c 6)) (list args a b c)) ; then I call: (arguments) (NIL 4 5 6) ; and it’s ok , as I expected… now if I call func with follow args: (arg...

Thank Ramarren for explanation !!

HI It seems that I still have some doubt on ‘ function ’ operator.. For example some code that I’m learning on the book (and also on the web)use it with lambda : In compose definition: (defun compose (&rest fns) (destructuring-bind (fnl . rest) (reverse fns) #'(lambda (&rest args) (red...

ohh good
thanks for explanation

HI in the book Graham says about closure : """When a function refers to a variable defined outside it, it's called a free variable. A function that refers to a free lexical variable is called a closure The variable must persist as long as the function does.""" and after...

Hi and thanks very much guys for good explanations!!!
eventually I continue to make the same mistake!! uffff : I forget that it’s possible initialize a variable without value, then take nil to default…

like compare-to result backref in wvxvw's code ..
thanks again!!!

HI Paul , wvxvw and stackman ...thanks for your support and suggestions!! ;) Now I have some questions for wvxvw about his syntax's code that are new for me :roll: First: ---- the third, fourth and fifth expressions in the fisrt “ do” ’s argument : compare-to result backref will be evaluated a...

HI the exercise says: """Define iterative and recursive versions of a function that takes an object x and vector v, and returns a list of all the objects that immediately precede x in v: > (precedes #\a "abracadabra") (#\c #\d #\r) """ ok, my solution (iterati...

opss'!!!
perfect thanks!

HI If I try to make a resizable string with make-array , but error raises with vector-push ..: (defparameter str (make-array 10 :fill-pointer 0 :adjustable t :element-type 'character)) >STR (vector-push 'a' str) ;;error raise: value STR is not of the expected type (AND ARRAY (SATISFIES ARRAY-HAS-FIL...