Creates a pattern.

Basic

Pattern.new(
  fn %Event{body: %SomeEvent{field: value}} ->
    value == :a
  end
)

Pattern.new(
  fn %Event{body: %SomeEvent{field: :a}} -> true end
)
# or shortly:
Pattern.new(%SomeEvent{field: :a})

value = :a
Pattern.new(%SomeEvent{field: ^value})

With guard

Pattern.new(
  fn %Event{source_saga_id: source} when not is_nil(source) -> true end
)

Matches all

Pattern.new(_)

Matches the specific type of struct

Pattern.new(%SomeEvent{})

Compose patterns

Pattern.new(
  fn %SomeEvent{field: value} ->
    Pattern.match?(other_pattern, value)
  end
)

Multiple patterns

Pattern.any([
  Pattern.new(fn %Resolve{id: id} -> id == "some id" end),
  Pattern.new(fn %Reject{id: id} -> id == "some id" end)
])

Multiple cases

Pattern.new(fn
  %SomeEvent{field: :ignore} -> false
  %SomeEvent{field: value} -> true
end)