Performance Design Guidlines

All rules in brief

• Don't use literal objects where constructors can be used.
• Model.attributes and __attributes must be an object. Operations deoptimizing it to hash must be avoided.
  • All known elements must be initialized in constructor in the same order.
  • On new models, id attribute must exist but set to undefined.
  • Always use dedicated constructors for these objects copy and creation.
  • Never delete elements from attributes.
• Function's arguments
  • Don't write to function arguments
  • Don't pass 'arguments' object through, except for apply.
  • Avoid using 'arguments' in hot spots, create specialized functions instead.
• Functions general rules
  • Avoid generic functions, rely on attributes and model type information whenever possible.
  • Use ad-hoc polymorphic functions only when necessary.
  • Split ad-hoc polymorphic functions to the set of type-specialized functions.
  • Avoid long functions.
  • Move for-in loops operating on hash in separate functions.
  • Avoid exceptions
  • Use loop unrolling with compilation to Function for hot spots.