This table does not represent the complete Scheme language. It includes the nonstandard Scheme primitives that we use in this book, and it omits many standard ones that are not needed here.
'
Abbreviation for (quote …).
* Multiply numbers.
+ Add numbers.
- Subtract numbers.
/ Divide numbers.
< Is the first argument less than the second?
<= Is the first argument less than or equal to the second?
= Are two numbers equal? (Like equal? but works only for numbers).
> Is the first argument greater than the second?
>= Is the first argument greater than or equal to the second?
abs Return the absolute value of the argument.
accumulate Apply a combining function to all elements
(see here).
align Return a string spaced to a given width (see here).
and (Special form) Are all of the arguments true values (i.e., not #f)?
appearances Return the number of times the first argument is in the second.
append Return a list containing the elements of the argument lists.
apply Apply a function to the arguments in a list.
assoc Return association list entry matching key.
before? Does the first argument come alphabetically before the second?
begin (Special form) Carry out a sequence of
instructions (see here).
bf Abbreviation for butfirst.
bl Abbreviation for butlast.
boolean? Return true if the argument is #t or #f.
butfirst Return all but the first letter of a word, or word of a sentence.
butlast Return all but the last letter of a word, or word of a sentence.
c...r Combinations of car and
cdr (see here).
car Return the first element of a list.
cdr Return all but the first element of a list.
ceiling Round a number up to the nearest integer.
children Return a list of the children of a tree node.
close-all-ports Close all open input and output ports.
close-input-port Close an input port.
close-output-port Close an output port.
cond (Special form) Choose among several alternatives
(see here).
cons Prepend an element to a list.
cos Return the cosine of a number (from trigonometry).
count Return the number of letters in a word or number of words in a sentence.
datum Return the datum of a tree node.
define (Special form) Create a global name (for a procedure or other value).
display Print the argument without starting a new line.
empty? Is the argument empty, i.e., the empty word "" or the empty sentence ()?
eof-object? Is the argument an end-of-file object?
equal? Are the two arguments the same thing?
error Print an error message and return to the Scheme prompt.
even? Is the argument an even integer?
every Apply a function to each element of a word or
sentence (see here).
expt Raise the first argument to the power of the second.
filter Select a subset of a list (see here).
first Return first letter of a word, or first word of a sentence.
floor Round a number down to the nearest integer.
for-each Perform a computation for each element of a list.
if (Special form) Choose between two alternatives (see
here).
integer? Is the argument an integer?
item Return the $n$th letter of a word, or $n$th word of a sentence.
keep Select a subset of a word or sentence (see here).
lambda (Special form) Create a new procedure (see Chapter \lambchop).
last Return last letter of a word, or last word of a sentence.
length Return the number of elements in a list.
let (Special form) Give temporary names to values (see
here).
list Return a list containing the arguments.
list->vector Return a vector with the same elements as the list.
list-ref Select an element from a list (counting from zero).
list? Is the argument a list?
load Read a program file into Scheme.
log Return the logarithm of a number.
make-node Create a new node of a tree.
make-vector Create a new vector of the given length.
map Apply a function to each element of a list (see here).
max Return the largest of the arguments.
member Return subset of a list starting with selected element, or #f.
member? Is the first argument an element of the
second? (see here).
min Return the smallest of the arguments.
newline Go to a new line of printing.
not Return #t if argument is #f; return #f otherwise.
null? Is the argument the empty list?
number? Is the argument a number?
odd? Is the argument an odd integer?
open-input-file Open a file for reading, return a port.
open-output-file Open a file for writing, return a port.
or (Special form) Are any of the arguments true values (i.e., not #f)?
procedure? Is the argument a procedure?
quote (Special form) Return the argument, unevaluated
(see here).
quotient Divide numbers, but round down to integer.
random Return a random number ≥ 0 and smaller than the argument.
read Read an expression from the keyboard (or a file).
read-line Read a line from the keyboard (or a file), returning a sentence.
read-string Read a line from the keyboard (or a file), returning a string.
reduce Apply a combining function to all elements of
list (see here).
remainder Return the remainder from dividing the first number by the second.
repeated Return the function described by
f(f(⋅⋅⋅(f(x)))) (see here).
round Round a number to the nearest integer.
se Abbreviation for sentence.
sentence Join the arguments together into a big sentence.
sentence? Is the argument a sentence?
show Print the argument and start a new line.
show-line Show the argument sentence without surrounding parentheses.
sin Return the sine of a number (from trigonometry).
sqrt Return the square root of a number.
square Not a primitive! (define (square x) (* x x))
trace Report on all future invocations of a procedure.
untrace Undo the effect of trace.
vector Create a vector with the arguments as elements.
vector->list Return a list with the same elements as the vector.
vector-length Return the number of elements in a vector.
vector-ref Return an element of a vector (counting from zero).
vector-set! Replace an element in a vector.
vector? Is the argument a vector?
vowel? Not a primitive! (define (vowel? x) (member? x '(a e i o u)))
word Joins words into one big word.
word? Is the argument a word? (Note: numbers are words.)