Simply Scheme Support Definitions🔗ℹ

1 Introduction🔗ℹ

This library adds a Simply Scheme teaching language into DrRacket; the language is used in the textbook:

Simply Scheme / Introducing Computer Science, Second Edition

Brian Harvey and Matthew Wright

MIT Press, 1999

http://www.cs.berkeley.edu/~bh/ss-toc2.html

The original source of these programs can be found from the FTP site at ftp://ftp.cs.berkeley.edu/pub/scheme. The definitions in this library should correspond to those in "simply.scm" version 3.13 (8/11.98).

2 Quick Start🔗ℹ

Although we use these definitions from switching the DrRacket language level to Simply Scheme, this library can also be easily used as a #lang language.

For example, if your DrRacket language level has been set to Determine language from source, then the following example should run without any trouble:

#lang simply-scheme
(se (butlast (bf "this"))
"world")

3 Table of Scheme Primitives by Category🔗ℹ

(Primitives with a ’*’ are not part of standard Scheme)

4 Alphabetical Listing of Scheme Primitives🔗ℹ

(require simply-scheme)

package: simply-scheme

syntax
*

multiply numbers

syntax
+

add numbers

syntax
-

subtract numbers

syntax
/

divide numbers

syntax
<

Is the first argument less than the second?

syntax
<=

Is the first argument less than or equal to the second?

syntax
=

Are two numbers equal? (Like equal? but works only for numbers)

syntax
>

Is the first argument greater than the second?

syntax
>=

Is the first argument greater than or equal to the second?

syntax
abs

Return the absolute value of the argument.

syntax
accumulate

Apply a combining function to all the elements.

syntax
align

Return a string spaced to a given width.

syntax
and

(Special form) Are all of the arugments true values (i.e., not #f)?

syntax
appearances

Return the number of times the first argument is in the second.

syntax
append

Return a list containing the elements of the argument lists.

syntax
apply

Apply a function to the arguments in a list.

syntax
assoc

Return association list entry matching key.

syntax
before?

Does the first argument come alphabetically before the second?

syntax
begin

(Special form) Carry out a sequence of instructions.

syntax
bf

Abbreviation for butfirst.

syntax
bl

Abbreviation for butlast.

syntax
boolean?

Return true if the argument is #t or #f.

syntax
butfirst

Return all but the first letter of a word, or word of a sentence.

syntax
butlast

Return all but the last letter of a word, or word of a sentence.

syntax
c...r

Combinations of car and cdr.

syntax
car

Return the first element of a list.

syntax
cdr

Return all but the first element of a list.

syntax
ceiling

Round a number up to the nearest integer.

syntax
children

Return a list of the children of a tree node.

syntax
close-all-ports

Close all open input and output ports.

syntax
close-input-port

Close an input port.

syntax
close-output-port

Close an output port.

syntax
cond

(Special form) Choose among several alternatives.

syntax
cons

Prepend an element to a list.

syntax
cos

Return the cosine of a number (from trigonometry).

syntax
count

Return the number of letters in a word or number of words in a sentence.

syntax
datum

Return the datum of a tree node.

syntax
define

(Special form) Create a global name (for a procedure or other value).

syntax
display

Print the argument without starting a new line.

syntax
empty?

Is the arugment empty, i.e., the empty word "" or the empty sentence ()?

syntax
eof-object?

Is the argument an end-of-file object?

syntax
equal?

Are the two arguments the same thing?

syntax
error

Print an error message and return to the Scheme prompt.

syntax
even?

Is the argument an even integer?

syntax
every

Apply a function to each element of a word or sentence.

syntax
expt

Raise the first argument to the power of the second.

syntax
filter

Select a subset of a list.

syntax
first

Return first letter of a word, or first word of a sentence.

syntax
floor

Round a number down to the nearest integer.

syntax
for-each

Perform a computation for each element of a list.

syntax
if

(Special form) Choose between two alternatives.

syntax
integer?

Is the argument an integer?

syntax
item

Return the nth letter of a word, or nth word of a sentence.

syntax
keep

Select a subset of a word or sentence.

syntax
lambda

(special form) Create a new procedure.

syntax
last

Return last letter of a word, or last word of a sentence.

syntax
length

Return the number of elements in a list.

syntax
let

(Special form) Give temporary names to values.

syntax
list

Return a list containing the arguments.

syntax
list->vector

Return a vector with the same elements as the list.

syntax
list-ref

Select an element from a list (counting from zero).

syntax
list?

Is the argument a list?

syntax
load

Read a program file into Scheme.

syntax
log

Return the logarithm of a number.

syntax
make-node

Create a new node of a tree.

syntax
make-vector

Create a new vector of the given length.

syntax
map

Apply a function to each element of a list.

syntax
max

Return the largest of the arguments.

syntax
member

Return subset of a list starting with the selected element, or #f.

syntax
member?

Is the first argument an element of the second?

syntax
min

Return the smallest of the arguments.

syntax
newline

Go to a new line of printing.

syntax
not

Return #t if the argument is #f; return #f otherwise.

syntax
null?

Is the argument the empty list?

syntax
number?

Is the argument a number?

syntax
odd?

Is the argument an odd number?

syntax
open-input-file

Open a file for reading, return a port.

syntax
open-output-file

Open a file for writing, return a port.

syntax
or

(Special form) Are any of the arguments true values (i.e., not #f)?

syntax
procedure?

Is the argument a procedure?

syntax
quote

(Special form) Return the argument, unevaluated.

syntax
quotient

Divide number, but round down to integer

syntax
read

Read an expression from the keyboard (or a file).

syntax
read-line

Read a line from the keyboard (or a file), returning a sentence.

syntax
read-string

Read a line from the keyboard (or a file), returning a string.

syntax
reduce

Apply a combining function to all elements of list.

syntax
remainder

Return the remainder from dividing the first number by the second.

syntax
repeated

Return the function described by f(f(...(f(x)))).

syntax
round

Round a number to the nearest integer.

syntax
se

Abbreviation for sentence.

syntax
sentence

Join the arguments together into a big sentence.

syntax
sentence?

Is the argument a sentence?

syntax
show

Print the argument and start a new line.

syntax
show-line

Show the argument sentence without surrounding parentheses.

syntax
sin

Return the sine of a number (from trigonometry).

syntax
sqrt

Return the square root of a number.

syntax
square

Not a primitive! (define (square x) (* x x)).

syntax
trace

Report on all further invocations of a procedure.

syntax
untrace

Undo the effects of trace.

syntax
vector

Create a vector with the arguments as elements.

syntax
vector->list

Return a list with the same elements as the vector.

syntax
vector-length

Return the number of elements in a vector.

syntax
vector-ref

Return an element of a vector (counting from zero).

syntax
vector-set!

Replace an element in a vector.

syntax
vector?

Is the argument a vector?

syntax
vowel?

Not a primitive! (define (vowel? x) (member x ’(a e i o u)))

syntax
word

Joins words into one big word.

syntax
word?

Is the argument a word? (Note: numbers are words.)

syntax
write

Print the argument in machine-readable form.

5 Deviations from plain racket🔗ℹ

5.1 Strings are numbers🔗ℹ

One distinguishing feature of this language is the abstraction of numbers. Strings are also treated as numbers by the arithmetic operators:

> (+ "40" 2)
42

This can be enabled or disabled by using strings-are-numbers:

syntax
strings-are-numbers

If bool is set to #t, strings will be treated as numbers, and the arithmetic operators will be overloaded to work with strings. If bool is set to #f, strings will not be treated as numbers.

6 Differences from the book and things to fix🔗ℹ

FIXME: the other helper libraries haven’t been mapped yet. (things like functions.scm would be nice to have as a library.)

I also need to improve the documentation to use Scribble features; the current work is a rush job.

7 Thanks!🔗ℹ

Thanks to my professors at UC Berkeley, especially Brian Harvey and Dan Garcia. Yes, CS61A was the best computer science class I’ve taken.

Thanks to Reid Oda for catching a very ugly bug involving namespaces, and Matthew Flatt for telling me how to fix it. See http://list.cs.brown.edu/pipermail/plt-scheme/2007-February/016387.html.

1	Introduction
2	Quick Start
3	Table of Scheme Primitives by Category
4	Alphabetical Listing of Scheme Primitives
5	Deviations from plain racket
6	Differences from the book and things to fix
7	Thanks!

Simply Scheme Support Definitions🔗ℹ

1 Introduction🔗ℹ

2 Quick Start🔗ℹ

3 Table of Scheme Primitives by Category🔗ℹ

3.1 Words and Sentences🔗ℹ

3.2 Lists🔗ℹ

3.3 Trees🔗ℹ

3.4 Arithmetic🔗ℹ

3.5 True and False🔗ℹ

3.6 Variables🔗ℹ

3.7 Vectors🔗ℹ

3.8 Procedures🔗ℹ

3.9 Higher-Order Procedures🔗ℹ

3.10 Control🔗ℹ

3.11 Input / Output🔗ℹ

3.12 Files and Ports🔗ℹ

4 Alphabetical Listing of Scheme Primitives🔗ℹ

5 Deviations from plain racket🔗ℹ

5.1 Strings are numbers🔗ℹ

6 Differences from the book and things to fix🔗ℹ

7 Thanks!🔗ℹ