lifting matching variables from patterns in case

[Licenser]

Describe the problem you are trying to solve

We often have the situation where we match and extract data in a case clause, this data is stored in a nested fashion which can feel cumbersome to use and is possibly unintuitive that keys assigned in a record are not accessible as varaibles.

Describe the solution you'd like

A match form that lifts up the matched keys into local variables inside the catch so they can be accessed directly, for example (syntax here being a quick make up):

match event of
  # without lifting variables (current code)
  case res ~= %{present method, url ~= re|http://(?P<host>.*?)/(?P<path>.*)|} => "We are ${res.method}ing ${res.patrh} from host ${res.host}"
  # with lifting variables
  case ^ %{present method, url ~= re|http://(?P<host>.*?)/(?P<path>.*)|} => "We are ${method}ing ${patrh} from host ${host}"
end

Notes
An additional upside is that we would save the cost of creating and then deconstructing a record result making the lifted form a more performant option.