hierarchy.fn

# Built-in object zoo.
# This is the ideal case...

# The Global object is created at the start of any execution
# and is the parent object for all objects.
Global = () {

  # Alias of Bool.not().
  not = (obj) { obj.not() }
  
}

# In Fn, any custom value is automatically an Object.
Object = (obj) {

  # Returns a reference to itself.
  this = <builtin>

  # Returns true if two objects have the same value.
  eq = (other) { <builtin> }

  # Returns a string representation of the object.
  asString = () { <builtin> }

  # This function is run when the object is referenced like:
  # obj(1)
  # By default, it returns the property given by the argument.
  call = (propertyName) { <builtin> }

  # Returns the number of arguments the object will take when call()ed.
  arity = () { <builtin> }

  # Iterates over the properties of the object,
  # calling the given function for each one.
  each = (f) { <builtin> }

}

# A Bool represents either a true or false value.
Bool = (value) {
  # Include Object and override.
  include Object {
    eq = (other) { <builtin> }
    asString = () { <builtin> }
  }

  # Returns true if both this and the other are true.
  and = (other) { <builtin> }

  # Returns true if either this or the other are true.
  or = (other) { <builtin> }

  # Returns the opposite of the value:
  # (true).flip() = false
  # (false).flip() = true
  not = () { <builtin> }
}

# A Number represents a numeric value.
Number = (value) {
  include Object {
    eq = (other) { <builtin> }
    asString = () { <builtin> }
  })

  # Arithmetic operations.
  + = (other) { <builtin> }
  - = (other) { <builtin> }
  * = (other) { <builtin> }
  / = (other) { <builtin> }

  # Comparison operations.
  lessThan = (other) { <builtin> }
  moreThan = (other) { <builtin> }
}

# A String represents a collection of characters.
String = (value) {
  include Object {
    eq = (other) { <builtin> }
    asString = () { <builtin> }
  }
}

# A Def is a function definition:
# a set of instructions that can be called.
Def = (value) {
  include Object {
    asString = () { <builtin> }
  }
}

# A List is a collection of objects.
List = (...values) {
  include Object {
    eq = (other) { <builtin> }
    asString = () { <builtin> }
    each = (f) { <builtin> }
  }
}