Module: Gorillib::Hashlike::HashlikeViaAccessors

Defined in:
lib/gorillib/hashlike/hashlike_via_accessors.rb

Overview

Makes a Receiver thingie behave mostly like a hash.

By default, the hashlike methods iterate over the receiver attributes: instance #keys delegates to self.class.keys which calls receiver_attr_names. If you want to filter our add to the keys list, you can just override the class-level keys method (and call super, or not):

def self.keys
  super + [:firstname, :lastname] - [:fullname]
end

in addition to the below, by including Enumerable, this also adds

:each_cons, :each_entry, :each_slice, :each_with_index, :each_with_object,
:map, :collect, :collect_concat, :entries, :to_a, :flat_map, :inject, :reduce,
:group_by, :chunk, :cycle, :partition, :reverse_each, :slice_before, :drop,
:drop_while, :take, :take_while, :detect, :find, :find_all, :find_index, :grep,
:all?, :any?, :none?, :one?, :first, :count, :zip :max, :max_by, :min, :min_by,
:minmax, :minmax_by, :sort, :sort_by

As opposed to hash, does not define

default, default=, default_proc, default_proc=, shift, flatten, compare_by_identity
compare_by_identity? rehash

Instance Method Summary collapse

Instance Method Details

#[](key) ⇒ Object

Hashlike#[]

Element Reference -- Retrieves the value stored for key.

In a normal hash, a default value can be set; none is provided here.

Delegates to self.send(key)

Examples:

hsh = { :a => 100, :b => 200 }
hsh[:a] # => 100
hsh[:c] # => nil

Parameters:

  • key (Object) —

    key to retrieve

Returns:

  • (Object) —

    the value stored for key, nil if missing



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# File 'lib/gorillib/hashlike/hashlike_via_accessors.rb', line 48

def [](key)
  key = convert_key(key)
  self.send(key)
end

#[]=(key, val) ⇒ Object

Hashlike#[]= Hashlike#store

Element Assignment -- Associates the value given by val with the key given by key.

key should not have its value changed while it is in use as a key. In a normal hash, a String passed as a key will be duplicated and frozen. No such guarantee is provided here

Delegates to self.send("key=", val)

Examples:

hsh = { :a => 100, :b => 200 }
hsh[:a] = 9
hsh[:c] = 4
hsh    # => { :a => 9, :b => 200, :c => 4 }

hsh[key] = val                         -> val
hsh.store(key, val)                    -> val

Parameters:

  • key (Object) —

    key to associate

  • val (Object) —

    value to associate it with

Returns:



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# File 'lib/gorillib/hashlike/hashlike_via_accessors.rb', line 78

def []=(key, val)
  key = convert_key(key)
  self.send("#{key}=", val)
end

#hsh.delete(key) ⇒ Object, Nil #hsh.delete(key) {|Object| ... } ⇒ Object, Nil

Hashlike#delete

Deletes and returns the value from hsh whose key is equal to key. If the optional code block is given and the key is not found, pass in the key and return the result of block.

In a normal hash, a default value can be set; none is provided here.

Examples:

hsh = { :a => 100, :b => 200 }
hsh.delete(:a)                            # => 100
hsh.delete(:z)                            # => nil
hsh.delete(:z){|el| "#{el} not found" }   # => "z not found"

Overloads:

  • #hsh.delete(key) ⇒ Object, Nil

    Returns the removed object, nil if missing.

    Parameters:

    • key (Object) —

      key to remove

    Returns:

    • (Object, Nil) —

      the removed object, nil if missing

  • #hsh.delete(key) {|Object| ... } ⇒ Object, Nil

    Returns the removed object, or if missing, the return value of the block.

    Parameters:

    • key (Object) —

      key to remove

    Yields:

    • (Object) —

      called (with key) if key is missing

    Yield Parameters:

    • key

    Returns:

    • (Object, Nil) —

      the removed object, or if missing, the return value of the block



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# File 'lib/gorillib/hashlike/hashlike_via_accessors.rb', line 108

def delete(key, &block)
  key = convert_key(key)
  if has_key?(key)
    val = self[key]
    self.send(:remove_instance_variable, "@#{key}")
    val
  elsif block_given?
    block.call(key)
  else
    nil
  end
end

#keys ⇒ Array

Hashlike#keys

Returns a new array populated with the keys from this hashlike.

Examples:

hsh = { :a => 100, :b => 200, :c => 300, :d => 400 }
hsh.keys   # => [:a, :b, :c, :d]

Returns:

  • (Array) —

    list of keys

See Also:

  • Hashlike#values.


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# File 'lib/gorillib/hashlike/hashlike_via_accessors.rb', line 157

def keys
  instance_variables.map{|s| convert_key(s[1..-1]) }
end