Objects

Objects are the main attraction in Citron (but are in no way forced)

You may instantiate any object by the default Object::'new' method (all objects should treat this method as a request for a new instance)

or directly execute code in the newly created object instance by using Object::'cnew:'

Objects can interface each other only by their methods (no way to access object fields directly if said object does not expose a method for it)

In each object's context o execution, an implicit me reference refers to the object itself, and the object's properties are accessible by my qualified references.

Dumb example

var Person is Object cnew: { name => 'Dummy'. }.
#To add a method, use Object::'on:do:'
Person on: 'new:' do: {:name ^me cnew: { name => name. }. }.
Person on: 'name' do: { ^my name. }, #You are most welcome to chain these should you wish to
 on: 'greet:' do: {:other
    #just assume other responds to 'name'
    Pen writeln: 'Hello, ' + other name + ', I am ' + my name.
}. #All such methods implicitly return `me' if nothing is explicitly returned.

var p0 is Person new: 'Idiot'.
var p1 is Person new: 'Fool'.

p0 greet: p1. #p1 supports ::'name'
#let's try with something that doesn't
p1 greet: 'Semicolon'.

Dumb output

Hello, Fool, I am Idiot
Uncaught error has occurred.
Unknown method String::'name' was called
#4 name (test.ctr: 7)
#3 + (test.ctr: 7)
#2 writeln: (test.ctr: 7)
#1 greet: (test.ctr: 15)

Inheritance

The usual single-inheritance rules apply (only to methods, and calling the parent constructor should be explicit)

var P is Object new on: 'method' do: { ^'Parent method'. }.
var C is P new.
#Overrides have no special syntax
C on: 'method' do: { ^'Child method'. }.
Pen writeln: C method. #=> 'Child method'

Multiple inheritance is supported, in a way.

You may 'inherit' from other objects and delegate method calls to their defintiions:

var P0 is Object new on: 'test0' do: {^'test0'.}.
var P1 is Object new on: 'test1' do: {^'test1'.}.
var C is P0 new inheritFrom: P1.

#Now ::'test1' will properly work (it will not contain any references to P1)
C test1. #=> 'test1'