Terrapin LOGO - Logo PLUS


Wherever the phrase any object is used below, it should be taken to mean a list or a word or a string.

Procedures with the number of inputs marked * will accept more than the specified number if both the procedure name and its inputs are enclosed in parentheses. Print, for example, normally takes only one input but is quite happy with three (or more) when used like this:

(pr "hello "fred [how are you?])

User input is assumed to be lowercase. You might, of course, use caps lock to over-ride this.


1. Word, list and string processing primitives

i. Basic operations

first

last

butfirst or bf

butlast or bl

item

list

word

string

sentence or se

fput

lput

ascii

char

count

ii. Predicates

(Operations which output only"true or "false)

member?

word?

list?

string?

empty?

equal?

before?

iii. Input operations

(The default input device is the keyboard and a line is 'read' when the enter key is pressed. N.B. no prompt is supplied by these procedures but can be provided, for keyboard input, by using print with some suitable message)

readlist or rl

readstring

readcharacter or rc

iv. Output commands

(The default output device is the screen)

print or pr

fprint

print1

fprint1

v. Variables

make

local

thing

thing?

vi. Property lists

(A property list is a list of value-attribute pairs associated with a name)

pprop

creates or changes attribute-value pairs

gprop

remprop


Terrapin and Logo PLUS are trademarks of Terrapin, Inc.


Ron Brasington
Department of Linguistic Science
The University of Reading
Reading
UK

E-mail: ron.brasington@rdg.ac.uk