Class: Latinum::Collection

Inherits:
Object
  • Object
show all
Includes:
Enumerable
Defined in:
lib/latinum/collection.rb

Overview

Aggregates a set of resources, typically used for summing values.

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(names = Set.new) ⇒ Collection

Initialize the collection with a given set of resource names.



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# File 'lib/latinum/collection.rb', line 30

def initialize(names = Set.new)
	@names = names
	@resources = Hash.new {|hash, key| @names << key; BigDecimal.new("0")}
end

Instance Attribute Details

#names ⇒ Object (readonly)

All resource names which have been added to the collection, e.g. ‘[’NZD’, ‘USD’]‘.



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# File 'lib/latinum/collection.rb', line 36

def names
  @names
end

#resources ⇒ Object (readonly)

A map of ‘name` => `total` for all added resources. Totals are stored as BigDecimal instances.



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# File 'lib/latinum/collection.rb', line 39

def resources
  @resources
end

Instance Method Details

#<<(object) ⇒ Object

Add a resource, an array of resources, or another collection into this one.



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# File 'lib/latinum/collection.rb', line 47

def << object
	case object
	when Resource
		add(object)
	when Array
		object.each { |resource| add(resource) }
	when Collection
		object.resources.each { |name, amount| @resources[name] += amount }
	end
	
	return self
end

#[](key) ⇒ Object

Get a ‘Resource` for the given name:



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# File 'lib/latinum/collection.rb', line 61

def [] key
	Resource.new(@resources[key], key)
end

#[]=(key, amount) ⇒ Object

Set a ‘BigDecimal` value for the given name:



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# File 'lib/latinum/collection.rb', line 66

def []= key, amount
	@resources[key] = amount
end

#add(resource) ⇒ Object

Add a resource into the totals.



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# File 'lib/latinum/collection.rb', line 42

def add resource
	@resources[resource.name] += resource.amount
end

#each ⇒ Object 



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# File 'lib/latinum/collection.rb', line 70

def each
	return to_enum(:each) unless block_given?
	
	@resources.each do |key, value|
		yield Resource.new(value, key)
	end
end