range, map, and apply
'(val1 val2 ... valn) - a list of n values.
(list exp1 exp2 ... expn) - create a list by evaluating each of the
expressions and then joining together their values.
(make-list n val) - make a list of n copies of val.
(range n) - create a list of all the natural numbers strictly less
than n (starting with 0).
(range s n) - create a list of all the natural numbers between m
(inclusive) and n (exclusive).
(range s n i) - create a list of all the natural numbers between m
(inclusive) and n (exclusive), incrementing by i each time.
(apply fun lst) - apply the function to all the elements of the
list, en masse.
(filter pred? lst) - Select only the elements of the list for
which the predicate holds.
(map fun lst) - apply the function to each element of the list.
(map fun (list val1 val2 ... valn)) gives you
(list (fun val1) (fun val2) ... (fun valn)).
(map fun lst1 lst2) - create a new list by applying the function to
corresponding pairs of elements from the two lists. You can also use
map with more than two lists.
(reduce binproc lst) - reduce a list to a single value
(sort lst compare?) - sort a list.
(tally predicate? lst) - count how many values meet the predicate.
(length lst) - Determine how many elements are in a list.
(reverse lst) - Create a new list with the elements in the opposite
order.
(append lst1 lst2) - Join two lists together.
(take lst n) - Build a new list consisting of the first n elements
of lst.
(drop lst n) - Build a new list consisting of all but the first n
elements of lst.
(list-ref lst n) - Extract element n of the list. (Remember that
lists start with element 0.)
(index-of val lst) - Determine the position of val in lst. (It
turns out the position is how many values need to be dropped
from lst to reach val.)
(indexes-of lst val) - Find all the indices of the value in the list.
(lambda (params) body) - a procedure in the standard form. When applied to some values (arguments), substitutes the arguments for the parameters in the body and evaluates the new expression. For example, (lambda (x) (+ x 5)) adds 5 to x.
(o f1 f2 f3 ... fn) - creates a procedure that takes one value and applies fn to that value, then fn-1 to that result, … then ` f3 to that result, then f2 to that result, and finally f1 to the result, returning the output of f1. For example, (o add1 square) is a procedure that squares its parameter and then adds 1.
(cut expression) - creates a procedure that takes one parameter for each “hole” <>. For example, (cut (* <> 5)) is a procedure that divides its parameter by 5.
a. If you have not done so already, you may want to open a separate tab or window in your browser for the varous readings.
b. Introduce yourself to your partner. Describe your strengths and approaches to work.
c. Review the double-dagger problems with your partner.
d. The person closer to the board is Side A. The other is Side B.
e. Load the lab.
f. Get started.