ChrisPenner

Optics By Example Cheat Sheets

The following are appendices from Optics By Example, a comprehensive guide to optics from beginner to advanced! If you like the content below, there's plenty more where that came from; pick up the book!

• Operators
• Composition Guide
• Substitution Guide
• Optical Constarints and Types

Operator Cheat Sheet

chrisdone

{-# LANGUAGE FlexibleInstances #-}
-- | Monoids with holes. The 'HoleyMonoid' allows building monoidal values of which certain components are to be filled in later. For example:
--
-- > > let holey = now "x = "
-- >             . later show
-- >             . now ", y = "
-- >             . later show
-- > > run holey 3 5
-- > "x = 3, y = 5"
--

justinweiss

# Call scopes directly from your URL params:
#
#     @products = Product.filter(params.slice(:status, :location, :starts_with))
module Filterable
  extend ActiveSupport::Concern

  module ClassMethods
    
    # Call the class methods with names based on the keys in <tt>filtering_params</tt>
    # with their associated values. For example, "{ status: 'delayed' }" would call