Instruction manual

29
5. Other Commands
edit n enter the Logo editor and open an edit window.
load n transfers the contents of the file specified by its
input from the disk to the workspace.
save n save the contents of the workspace to a file on
the disk.
open n open a device. If the specified file or device does
not exist, OPEN outputs FALSE.
close n close a device.
print n print its inputs to the output stream.
type n print its inputs on-screen, and the prompt appears
after the last character printed.
thing n output the value associated with the variable
named in the input.
pause temporarily halt the execution of a procedure.
wait n insert a pause before the next instruction is run.
The length of the pause is the input to WAIT times
1/20 of a second.
readchar (rc) output the first character from the input stream.
If no character is waiting to be read, READCHAR
waits for input from the keyboard.
readword (rw) output in the form of a word from the input
stream. If no line is waiting to be read, READWORD
waits for input from the keyboard.
readlist (rl) output in the form of a list from the input stream.
If no line is waiting to be read, READLIST waits
for input from the keyboard.
cleartext (ct) clear output window content.
pots print the titles of all you defined procedures. POTS
stands for “Print Out Titles”.
erase (er) n remove the definition of its input from the
workspace. The input to ERASE must be a
procedure name.
eraseall (erall) remove all procedures and variables from the
workspace.
6. Flow control Commands
if <condition> then [commands] The <condition> must result in a value of either
TRUE or FALSE. If the <condition> is TRUE then
the commands in [commands] are executed.
if <condition> then [commands1] If <condition> is TRUE then the commands else
[commands2] in [commands1] are executed.
Otherwise the commands in [commands2] are
executed.
else [commands2]