Class: I8::Struct::Hash

Inherits:

Hash

• Object
• Hamster::Hash
• Hash
• I8::Struct::Hash

Includes:

I8::Struct, NRSER::Props::Immutable::Hash

Defined in:

lib/nrser/labs/i8/struct/hash.rb

Overview

Base class for Hash-based “propertied” (NRSER::Props) structs created by new.

See Also:

• I8::Struct
• NRSER::Props
• NRSER::Props::Immutable::Hash

Constant Summary

Constants included from NRSER::Props::Immutable::Hash

NRSER::Props::Immutable::Hash::STORAGE

Class Method Summary

• .new(*args, **kwds, &block) ⇒ Object

  This method does two totally different things depending on what ‘self` is:.

Methods included from NRSER::Props::Immutable::Hash

included

Methods inherited from Hamster::Hash

#as_json, #to_mutable, #to_yaml

Methods included from NRSER::Ext::Tree

#each_branch, #leaves, #map_branches, #map_leaves, #map_tree

Class Method Details

.self.new(**prop_defs, &class_body) ⇒ Class<I8::Struct::Hash> .self.new(*args, **kwds, &block) ⇒ I8::Struct::Hash

This method does two totally different things depending on what ‘self` is:

1. If ‘self` is I8::Struct::Hash, we want to build a new struct class.

2. Otherwise, we want to defer up to ‘super` to create a new instance of `self`.

Overloads:

• .self.new(**prop_defs, &class_body) ⇒ Class<I8::Struct::Hash>

  When ‘self` is I8::Struct::Hash, the method builds a new subclass, along the lines of how I8::Struct.new and `::Struct.new` work.

  Examples:

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

  Parameters:

  • prop_defs (Hash<Symbol, (NRSER::Types::Type | Hash<Symbol, Object>)>) —

    Map of property names to the value(s) needed to create them.

    ‘prop_defs` values can each be:

    1. NRSER::Types::Type - used as the NRSER::Props::Prop#type, with all the NRSER::Props::Prop‘s other values left as defaults.

    2. Object> - full prop configuration, passed in to NRSER::Props::Metadata#prop.

  • class_body (Proc?) —

    Optional block to evaluate as the new class’s body.

  Returns:

  • (Class<I8::Struct::Hash>) —

    New structure class.

• .self.new(*args, **kwds, &block) ⇒ I8::Struct::Hash

  When ‘self` **is not** I8::Struct::Hash, this method simply forwards all parameters up to it’s super method, which will create a new instance as usual.

  Examples:

  Point < I8::Struct::Hash
  # => true
  
  Point.new x: 1, y: 2 # Passes through to super method to construct
  # => Point[:y => 2, :x => 1]

  Returns:

  • (I8::Struct::Hash) —

    New instance.

# File 'lib/nrser/labs/i8/struct/hash.rb', line 92

def self.new *args, **kwds, &block
  # Are we {I8::Struct::Hash}? (See method doc).
  if self == I8::Struct::Hash
    # Yes, we are. Time to build a new struct class.
    
    # Make sure we weren't given an positional `args`.
    unless args.empty?
      raise NRSER::ArgumentError.new \
        "Can not supply positional args when building new",
        "{I8::Struct::Hash}",
        args: args,
        kwds: kwds
    end

    # Create the new subclass
    Class.new( I8::Struct::Hash ) do
      kwds.each do |name, value|
        prop_kwds = t.match value,
          t.type, ->( type ) {{ type: type }},
          t.hash_, value
        
        prop name, **prop_kwds
      end
      
      class_exec &block if block
    end

  else
    # No, we are a built struct. Defer up to `super` to create an instance.
    
    # NOTE  Weirdness ahead. See NOTE in {I8::Struct::Vector.new}
    if kwds.empty?
      super( *args, &block )
    else
      super( *args, **kwds, &block )
    end

  end
end