Class: Remap::Rule::Enum

Inherits:
Proxy
  • Object
show all
Defined in:
lib/remap/rule/support/enum.rb

Class Method Summary collapse

Instance Method Summary collapse

Methods inherited from Proxy

const_missing, #tap

Class Method Details

.call(&block) ⇒ Any

Builds an enumeration using the block as context

Examples:

enum = Remap::Rule::Enum.call do
  from "B", to: "C"
  value "A"
  otherwise "D"
end

enum.get("A") # => "A"
enum.get("B") # => "C"
enum.get("C") # => "C"
enum.get("MISSING") # => "D"

Returns:

  • (Any) 


31
32
33
34
35
36
37
 
# File 'lib/remap/rule/support/enum.rb', line 31

def self.call(&block)
  unless block
    raise ArgumentError, "no block given"
  end

  new.tap { _1.execute(&block) }
end

Instance Method Details

#[](key) ⇒ Maybe

Returns:

  • (Maybe) 


59
60
61
 
# File 'lib/remap/rule/support/enum.rb', line 59

def [](key)
  mappings[key]
end

#default ⇒ Maybe

Returns:

  • (Maybe) 


12
 
# File 'lib/remap/rule/support/enum.rb', line 12

option :default, default: -> { None() }

#from(*keys, to:) ⇒ void

This method returns an undefined value.



64
65
66
67
68
69
70
71
 
# File 'lib/remap/rule/support/enum.rb', line 64

def from(*keys, to:)
  value = Some(to)

  keys.each do |key|
    mappings[key] = value
    mappings[to] = value
  end
end

#get(key) {|String| ... } ⇒ Any Also known as: call

Translates key into a value using predefined mappings

Parameters:

  • key (#hash)

Yields:

  • (String) —

    If the key is not found & no default value is set

Returns:

  • (Any) 


47
48
49
50
51
52
53
54
55
 
# File 'lib/remap/rule/support/enum.rb', line 47

def get(key, &error)
  unless error
    return get(key) { raise Error, _1 }
  end

  self[key].bind { return _1 }.or do
    error["Enum key [#{key}] not found among [#{mappings.keys.inspect}]"]
  end
end

#mappings ⇒ Hash

Returns:

  • (Hash) 


9
 
# File 'lib/remap/rule/support/enum.rb', line 9

option :mappings, default: -> { Hash.new { default } }

#otherwise(value) ⇒ void

This method returns an undefined value.



81
82
83
 
# File 'lib/remap/rule/support/enum.rb', line 81

def otherwise(value)
  mappings.default = Some(value)
end

#value(*ids) ⇒ void

This method returns an undefined value.



74
75
76
77
78
 
# File 'lib/remap/rule/support/enum.rb', line 74

def value(*ids)
  ids.each do |id|
    from(id, to: id)
  end
end