StructX

StructX is an extension of Ruby standard Struct. The diffences are that 1) the constructor handles hash table as key-value pairs, 2) you can specify members as statements, and 3) you can set default values of member. StructX's API is compatible with Struct.

Installation

$ gem install structx

Usage

Constructor with hash table

StructX.new(:x, :y, :z).new(x: 1, y: 2, z: 3) #=> #<struct x=1, y=10, z=100>

Member declarations

class A < StructX
  member :x
  member :y
  member :z
end
A.new(1, 2, 3) #=> #<struct A x=1, y=2, z=3>

Default values

class B < StructX
  member :x
  member :y, default: 10
  member :z, default: 100
end
B.new(1) # => #<struct B x=1, y=10, z=100>

You can set dynamic default values with proc object.

class B < StructX
  member :x, default: lambda {$N}
  member :y, default: lambda {|obj| $N+1}
  member :z, default: lambda {|obj, data| $N+2}
end
$N = 1
B.new # => #<struct B x=1, y=2, z=3>
$N = 10
B.new # => #<struct B x=10, y=11, z=12>

Immutable mode

class C < StructX
  immutable true
  member :x
  member :y
  member :z
end
orig = C.new(1, 2, 3) #=> #<struct C x=1, y=2, z=3>
updated = orig.set(x: 4, y: 5, z: 6) #=> #<struct C x=4, y=5, z=6>
orig.values    #=> [1, 2, 3]
updated.values #=> [4, 5, 6]

Documentation

• API Documentation

License

StructX is free software distributed under MIT license. The following files are copied from ruby's test case, so you should keep its lisense.

• test/ruby/1.9/test_struct.rb
• test/ruby/1.9/envutil.rb
• test/ruby/2.0/test_struct.rb
• test/ruby/2.0/envutil.rb

Contributing

1. Fork it
2. Create your feature branch (git checkout -b my-new-feature)
3. Commit your changes (git commit -am 'Add some feature')
4. Push to the branch (git push origin my-new-feature)
5. Create new Pull Request