IO
Everyone adores I/O, well, not everyone, that poor processor that is always kept waiting sure doesn't.
The basic input methods are available with the Program::'input', Program::'waitForInput' and Program::'getCharacter' (only available with termios)
the more...sophisticated actions can be performed with stdin : File special: 'sdin' will give an auto-cleaning handle to it.
Input
var thing is Program waitForInput.
Pen writeln: 'in reverse: ' + thing reverse.
Pen writeln: 'SPACEY: ' + (thing characters join: ' ').
#This will raise an exception if any extra character remains after conversion
Pen writeln: 'Trying to make a number of it: ' + (thing toNumber).
Output for 123test:
123test
in reverse:
tset321
SPACEY: 1 2 3 t e s t
Uncaught error has occurred.
cannot build number, extranous characters in string
#3 toNumber (test.ctr: 5)
#2 + (test.ctr: 5)
#1 writeln: (test.ctr: 5)
Palindromes, because every language needs one
var is_palindrome is {:str
^str reverse = str.
}.
{^True.} whileTrue: {
Pen write: 'What be your text? '.
Pen writeln: (is_palindrome applyTo: Program waitForInput trim, either: 'Yep, that\'s a palindrome' or: 'Nope, not a plaindrome').
}.
Profoundly, the output:
What be your text? str
Nope, not a plaindrome
What be your text? 1001
Yep, that's a palindrome
What be your text? []
Nope, not a plaindrome
^C
Files
Files are fun things, they respond to read, readBytes:, write: and more!
Opening a file
You may implicitly open a file for reading or writing depending on the operation (no need to state open:)
#You may write to it normally
File new: 'test', write: 'This is a test\n' * 100.
#Or open it explicitly
File new: 'test', open: 'w+', write: 'This be a test\n', close. #Resources are cleaned by the garbage collector, but explicitly closing it is preferred
Special-purpose Files
there are three special file descriptors stdin stdout and stderr
You may access these by File::'special:'
Note that stdin does not allow writes, and the other two do not allow reads.