Class: Remap::Selector::Key

Inherits:
Unit
  • Object
show all
Defined in:
lib/remap/selector/key.rb

Overview

Selects value at key from state

Examples:

Select the value at key :name from a hash

state = Remap::State.call({ name: "John" })
selector = Remap::Selector::Key.new(:name)

selector.call(state) do |state|
  state.fetch(:value)
end

Instance Method Summary collapse

Instance Method Details

#call(outer_state) {|| ... } ⇒ State<U>

Selects #key from state and passes it to block

Parameters:

  • outer_state (State<Hash<K, V>>)

Yield Parameters:

Yield Returns:

Returns:



30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
 
# File 'lib/remap/selector/key.rb', line 30

def call(outer_state, &block)
  unless block_given?
    raise ArgumentError, "The key selector requires an iteration block"
  end

  outer_state.bind(key: key) do |hash, state|
    requirement[hash] do
      state.fatal!("Expected hash but got %p (%s)", hash, hash.class)
    end

    value = hash.fetch(key) do
      state.ignore!("Key %p (%s) not found in hash %p (%s)",
                    key,
                    key.class,
                    hash,
                    hash.class)
    end

    state.set(value, key: key).then(&block)
  end
end

#key ⇒ #hash

Returns #hash.

Returns:

  • (#hash) —

    #hash



18
 
# File 'lib/remap/selector/key.rb', line 18

attribute :key, Types::Key