Module: Arborist::HashUtilities

Included in:

Event::NodeDelta, Manager, Node, Node::Ack, Node::Service, Subscription, TreeAPI

Defined in:

lib/arborist/mixins.rb

Overview

A collection of utilities for working with Hashes.

Class Method Summary

• .compact_hash(hash) ⇒ Object

  Recursively remove hash pairs in place whose value is nil.

• .hash_matches(hash, key, val) ⇒ Object

  Returns true if the specified hash includes the specified key, and the value associated with the key either includes val if it is a Hash, or equals val if it’s anything but a Hash.

• .merge_recursively(key, oldval, newval) ⇒ Object

  Recursive hash-merge function.

• .stringify_keys(hash) ⇒ Object

  Return a version of the given hash with its keys transformed into Strings from whatever they were before.

• .symbolify_keys(hash) ⇒ Object (also: internify_keys)

  Return a duplicate of the given hash with its identifier-like keys transformed into symbols from whatever they were before.

Class Method Details

.compact_hash(hash) ⇒ Object

Recursively remove hash pairs in place whose value is nil.

# File 'lib/arborist/mixins.rb', line 366

def compact_hash( hash )
	hash.each_key do |k|
		hash.delete( k ) if hash[ k ].nil?
		compact_hash( hash[k] ) if hash[k].is_a?( Hash )
	end
end

.hash_matches(hash, key, val) ⇒ Object

Returns true if the specified hash includes the specified key, and the value associated with the key either includes val if it is a Hash, or equals val if it’s anything but a Hash.

# File 'lib/arborist/mixins.rb', line 377

def hash_matches( hash, key, val )
	actual = hash[ key ] or return false

	if actual.is_a?( Hash )
		if val.is_a?( Hash )
			return val.all? {|subkey, subval| hash_matches(actual, subkey, subval) }
		else
			return false
		end
	else
		return actual == val
	end
end

.merge_recursively(key, oldval, newval) ⇒ Object

Recursive hash-merge function

# File 'lib/arborist/mixins.rb', line 341

def merge_recursively( key, oldval, newval )
	case oldval
	when Hash
		case newval
		when Hash
			oldval.merge( newval, &method(:merge_recursively) )
		else
			newval
		end

	when Array
		case newval
		when Array
			oldval | newval
		else
			newval
		end

	else
		newval
	end
end

.stringify_keys(hash) ⇒ Object

Return a version of the given hash with its keys transformed into Strings from whatever they were before.

# File 'lib/arborist/mixins.rb', line 305

def stringify_keys( hash )
	newhash = {}

	hash.each do |key,val|
		if val.is_a?( Hash )
			newhash[ key.to_s ] = stringify_keys( val )
		else
			newhash[ key.to_s ] = val
		end
	end

	return newhash
end

.symbolify_keys(hash) ⇒ Object Also known as: internify_keys

Return a duplicate of the given hash with its identifier-like keys transformed into symbols from whatever they were before.

# File 'lib/arborist/mixins.rb', line 322

def symbolify_keys( hash )
	newhash = {}

	hash.each do |key,val|
		keysym = key.to_s.dup.to_sym

		if val.is_a?( Hash )
			newhash[ keysym ] = symbolify_keys( val )
		else
			newhash[ keysym ] = val
		end
	end

	return newhash
end