Module: I8::Struct

Included in:
Hash, Vector
Defined in:
lib/nrser/labs/i8/struct.rb,
lib/nrser/labs/i8/struct/hash.rb,
lib/nrser/labs/i8/struct/vector.rb

Overview

‘I8::Struct` is an immutable rendition of the Ruby standard lib `::Struct` using the NRSER::Props system.

It’s intended to help make it quick and easy to create little immutable propertied objects, with all the type-checking and serialization stuff that comes with NRSER::Props.

‘Struct` itself is a module with a Struct.new method that creates new subclasses of either Hash or Vector, which themselves are respective subclasses of Hash and Vector, and include NRSER::Props::Immutable::Hash and NRSER::Props::Immutable::Vector.

### Identifying Classes Built by ‘I8::Struct`

Both Hash and Vector also include ‘I8::Struct` itself for the convenience of shit like:

Point = I8::Struct.new x: t.int, y: t.int

Point.included_modules.include? I8::Struct
#  => true

p = Point.new x: 1, y: 2
p.is_a? I8::Struct
# => true

‘I8::Struct` has only class (static) methods, so no functionality is actually added from `include I8::Struct`.

### Gotchas

The code below *doesn’t* work how you might want or expect it:

Point = I8::Struct.new x: t.int, y: t.int
Point.is_a? I8::Struct
# => false

Opposed to how Class works:

C = Class.new
C.is_a? Class
# => true

However, this is the same as how the stdlib’s [::Struct][] behaves:

S = ::Struct.new :x
S.is_a? ::Struct
# => false

[::Struct]: ruby-doc.org/core/Struct.html

Examples:

One-Liner

Person = I8::Struct.new name: t.non_empty_str, age: t.non_neg_int
nrser = Person.new name: "Neil", age: 34

Extend a ‘I8::Struct` to add methods

class Rectangle \
  < I8::Struct.new( width: t.non_neg_int, length: t.non_neg_int )

  def area
    width * length
  end

end # class Rectangle

Defined Under Namespace

Classes: Hash, Vector

Class Method Summary collapse

Class Method Details

.new(*vector_prop_defs, **hash_prop_defs, &class_body) ⇒ Object 



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# File 'lib/nrser/labs/i8/struct.rb', line 148

def self.new *vector_prop_defs, **hash_prop_defs, &class_body
  check_new_args! vector_prop_defs, hash_prop_defs
  
  if !vector_prop_defs.empty?
    raise NotImplementedError.new "I8::Struct::Vector is TODO, sorry"
    # I8::Struct::Vector.new *vector_prop_defs, &class_body
  else
    I8::Struct::Hash.new **hash_prop_defs, &class_body
  end
end