Module: Enumerable

Defined in:
lib/enumerate_hash_values/core_extensions/enumerable.rb

Overview

:nodoc:

Instance Method Summary collapse

Instance Method Details

#collect_to_hash(hash_class = Hash) ⇒ Object Also known as: map_to_hash

Wraps the common pattern of doing:

enumerable.inject({}) do |hash, item|
  some_key        = item.key
  some_value      = item.value
  hash[some_key]  = some_value
  hash
end

Using collect_to_hash instead:

enumerable.collect_to_hash do |item|
  some_key = item.key
  some_value = item.value
  [some_key, some_value]
end

Examples:

(1..3).collect_to_hash { |number| [number, number * 10] } # => { 1 => 10, 2 = > 20, 3 => 30 }
%w(a b c).map_to_hash { |letter| [letter, letter[0]] }    # => { 'a' => 97, 'b' => 98, 'c' => 99 }

Aliases map_to_hash

Raises:

  • (ArguementError) 


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# File 'lib/enumerate_hash_values/core_extensions/enumerable.rb', line 26

def collect_to_hash(hash_class = Hash)
  raise ArguementError.new("#{hash_class} is not a Hash") unless hash_class.ancestors.include?(Hash)

  inject(hash_class.new) do |hash, item|
    key, value = yield(item)
    hash[key] = value
    hash
  end
end

#collect_to_hash_values(hash_class = Hash) ⇒ Object Also known as: map_to_hash_values

Similar to collect_to_hash, but the specified block only needs to return the hash value for each enumerated item. The items themselves will serve as the hash keys.

(1..3).collect_to_hash_values { |number| number * 10 }  # => { 1 => 10, 2 = > 20, 3 => 30 }
%w(a b c).map_to_hash_values(&:to_sym)                  # => { 'a' => :a, 'b' => :b, 'c' => :c }

Aliases map_to_hash_values



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# File 'lib/enumerate_hash_values/core_extensions/enumerable.rb', line 45

def collect_to_hash_values(hash_class = Hash)
  collect_to_hash(hash_class) { |item| [item, yield(item)] }
end