Provider

A constructor for simple value objects, known as provider instances.
This value has a dual purpose:

• It is a function that can be called to construct 'struct'-like values:

  DataInfo = provider()
  d = DataInfo(x = 2, y = 3)
  print(d.x + d.y) # prints 5

  Note: Some providers, defined internally, do not allow instance creation
• It is a key to access a provider instance on a Target

  DataInfo = provider()
  def _rule_impl(ctx)
    ... ctx.attr.dep[DataInfo]

Create a new Provider using the provider function.