classes.md

Classes

---

Example

Object subclass: 'Person
    instanceVars: [ 'name, 'age ];

Person class >> newWithName: name andAge: age {
    # Primary constructor #
    ^self new |> (name: name | age: age)
};

Person >> isMinor {
    ^age < 21
};

Person >> asString {
    ^name + ", " + age asString
}

Person newWithName: "Elyan Poujol" andAge: 21
    |> println
# Elyan Poujol, 21 #

Getter/Setter auto generation

Object subclass: 'Person
    instanceVars: [ 'name, 'age ]

Methods are automatically created to access instance variables. In this case: name is a getter for the instance variable name and name: is a setter for the instance variable name. Same for age and age:.

Class creation syntactic sugar

Code like Object subclass: 'Hello don't magically pops the variable Hello into scope. The sub-classing messages are desugarized to Hello := Object subclass: 'Hello' when the class name parameter is a symbol literal.

Object subclass: 'Hello;  # Variable Hello is declared #

Object subclass: aString; # Cannot infer a name so no variable declared #

aName = 'MyClass;
Object subclass: aName; # Also nope (at least for now) #

Method creation syntactic sugar

Person >> isMinor {
    ^age < 21
}

Could be written as:

Person compile: "isMinor {
    ^age < 21
}"

Primitive method declaration syntactic sugar

MyClass :: method = 'primitiveMethod

Could be written as:

MyClass bind: 'method toPrimitive: 'primitiveMethod