Class: Hash

### Home Classes Methods

### In Files

- lib/backports/1.8.7/hash/constructor.rb
- lib/backports/1.8.7/hash/hash.rb
- lib/backports/1.9.1/hash/assoc.rb
- lib/backports/1.9.1/hash/default_proc.rb
- lib/backports/1.9.1/hash/rassoc.rb
- lib/backports/1.9.2/hash/keep_if.rb
- lib/backports/1.9.2/hash/select.rb
- lib/backports/2.0.0/hash/default_proc.rb
- lib/backports/2.0.0/hash/to_h.rb
- lib/backports/force/hash_select.rb
- lib/backports/rails/hash.rb

### Parent

Object

### Methods

- ::[]
- ::constructor_without_key_value_pair_form
- ::try_convert
- #assoc
- #default_proc=
- #default_proc_with_nil=
- #eql?
- #hash
- #keep_if
- #rassoc
- #reverse_merge
- #reverse_merge!
- #select!
- #select_with_hash_return
- #stringify_keys
- #stringify_keys!
- #symbolize_keys
- #symbolize_keys!
- #to_h

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# Hash

### Public Class Methods

[](*args) click to toggle source

    # File lib/backports/1.8.7/hash/constructor.rb, line 6
    def [](*args)
      if args.length == 1
        arg = args.first
        if (h = Backports.try_convert(arg, Hash, :to_hash))
          return allocate.replace(h)
        end
        if (kvps = Backports.is_array?(arg))
          h = {}
          kvps.each do |elem|
            next unless arr = Backports.is_array?(elem)
            next unless (1..2).include? arr.size
            h[arr.at(0)] = arr.at(1)
          end
          return h
        end
      end
      constructor_without_key_value_pair_form(*args)
    end

Also aliased as: constructor_without_key_value_pair_form
constructor_without_key_value_pair_form(*args) click to toggle source
Alias for: []
try_convert(x) click to toggle source

    # File lib/backports/1.9.1/hash/try_convert.rb, line 4
    def Hash.try_convert(x)
      Backports.try_convert(x, Hash, :to_hash)
    end

### Public Instance Methods

assoc(key) click to toggle source

    # File lib/backports/1.9.1/hash/assoc.rb, line 3
    def assoc(key)
      val = fetch(key) do
        return find do |k, v|
          [k, v] if k == key
        end
      end
      [key, val]
    end

default_proc=(proc) click to toggle source

    # File lib/backports/1.9.1/hash/default_proc.rb, line 5
    def default_proc=(proc)
      if proc == nil # nil accepted in Ruby 2.0
        self.default = nil
        self
      else
        replace(Hash.new(&Backports.coerce_to(proc, Proc, :to_proc)).merge!(self))
      end
    end

default_proc_with_nil=(proc) click to toggle source

    # File lib/backports/2.0.0/hash/default_proc.rb, line 6
    def default_proc_with_nil=(proc)
      if proc == nil
        self.default = nil
        self
      else
        self.default_proc_without_nil=(proc)
      end
    end

eql?(other) click to toggle source

    # File lib/backports/1.8.7/hash/hash.rb, line 10
    def eql?(other)
      other.is_a?(Hash) &&
        size == other.size &&
        all? do |key, value|
          value.eql?(other.fetch(key){return false})
        end
    end

hash() click to toggle source

    # File lib/backports/1.8.7/hash/hash.rb, line 2
    def hash
      h = 0
      each do |key, value|
        h ^= key.hash ^ value.hash
      end
      h
    end

keep_if() click to toggle source

    # File lib/backports/1.9.2/hash/keep_if.rb, line 3
    def keep_if
      return to_enum(:keep_if) unless block_given?
      delete_if{|key, value| ! yield key, value}
    end

rassoc(value) click to toggle source

    # File lib/backports/1.9.1/hash/rassoc.rb, line 3
    def rassoc(value)
      k = key(value)
      v = fetch(k){return nil}
      [k, fetch(k)] if k || v == value
    end

reverse_merge(other_hash) click to toggle source

Standard in rails. See official documentation

    # File lib/backports/rails/hash.rb, line 3
    def reverse_merge(other_hash)
      other_hash.merge(self)
    end

reverse_merge!(other_hash) click to toggle source

Standard in rails. See official documentation

    # File lib/backports/rails/hash.rb, line 8
    def reverse_merge!(other_hash)
      replace(reverse_merge(other_hash))
    end

select!() click to toggle source

    # File lib/backports/1.9.2/hash/select.rb, line 3
    def select!
      return to_enum(:select!) unless block_given?
      raise "can't modify frozen hash" if frozen? # reject! won't do it for empty hashes...
      reject!{|key, value| ! yield key, value}
    end

select_with_hash_return() click to toggle source

    # File lib/backports/force/hash_select.rb, line 4
    def select_with_hash_return
      return to_enum(:select) unless block_given?
      Hash[select_without_hash_return{|k, v| yield [k, v]}]
    end

stringify_keys() click to toggle source

Standard in rails. See official documentation

    # File lib/backports/rails/hash.rb, line 23
    def stringify_keys
      Hash[map{|key,value| [key.to_s, value] }]
    end

stringify_keys!() click to toggle source

Standard in rails. See official documentation

    # File lib/backports/rails/hash.rb, line 28
    def stringify_keys!
      self.replace(self.stringify_keys)
    end

symbolize_keys() click to toggle source

Standard in rails. See official documentation

    # File lib/backports/rails/hash.rb, line 13
    def symbolize_keys
      Hash[map{|key,value| [(key.to_sym rescue key) || key, value] }]
    end

symbolize_keys!() click to toggle source

Standard in rails. See official documentation

    # File lib/backports/rails/hash.rb, line 18
    def symbolize_keys!
      self.replace(self.symbolize_keys)
    end

to_h() click to toggle source

    # File lib/backports/2.0.0/hash/to_h.rb, line 3
    def to_h
      self.class == Hash ? self : {}.replace(self)
    end

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