Class: Latinum::Resource

Inherits:
Object
  • Object
show all
Includes:
Comparable
Defined in:
lib/latinum/resource.rb

Overview

A fixed unit in a given named resource

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(amount, name) ⇒ Resource 



31
32
33
34
 
# File 'lib/latinum/resource.rb', line 31

def initialize(amount, name)
  @amount = amount.to_d
  @name = name
end

Instance Attribute Details

#amount ⇒ Object (readonly)

Returns the value of attribute amount.



28
29
30
 
# File 'lib/latinum/resource.rb', line 28

def amount
  @amount
end

#name ⇒ Object (readonly)

Returns the value of attribute name.



29
30
31
 
# File 'lib/latinum/resource.rb', line 29

def name
  @name
end

Class Method Details

.dump(resource) ⇒ Object 



92
93
94
 
# File 'lib/latinum/resource.rb', line 92

def dump(resource)
  resource.to_s if resource
end

.load(string) ⇒ Object 



88
89
90
 
# File 'lib/latinum/resource.rb', line 88

def load(string)
  parse(string) if string
end

.parse(string, default_name: nil) ⇒ Object 



82
83
84
85
86
 
# File 'lib/latinum/resource.rb', line 82

def parse(string, default_name: nil)
  amount, name = string.split(/\s+/, 2)
  
  self.new(amount, name || default_name)
end

Instance Method Details

#*(factor) ⇒ Object 



53
54
55
 
# File 'lib/latinum/resource.rb', line 53

def * factor
  self.class.new(@amount * factor, @name)
end

#+(other) ⇒ Object

By default, we can only add and subtract if the name is the same

Raises:

  • (ArgumentError) 


37
38
39
40
41
 
# File 'lib/latinum/resource.rb', line 37

def + other
  raise ArgumentError.new("Cannot operate on different currencies!") if @name != other.name
  
  self.class.new(@amount + other.amount, @name)
end

#-(other) ⇒ Object

Raises:

  • (ArgumentError) 


43
44
45
46
47
 
# File 'lib/latinum/resource.rb', line 43

def - other
  raise ArgumentError.new("Cannot operate on different currencies!") if @name != other.name
  
  self.class.new(@amount - other.amount, @name)
end

#-@ ⇒ Object 



49
50
51
 
# File 'lib/latinum/resource.rb', line 49

def -@
  self.class.new(-@amount, @name)
end

#<=>(other) ⇒ Object 



73
74
75
76
77
78
79
 
# File 'lib/latinum/resource.rb', line 73

def <=> other
  if @name == other.name
    @amount <=> other.amount
  else
    @name <=> other.name
  end
end

#exchange(rate, name, precision = nil) ⇒ Object 



57
58
59
60
61
62
63
 
# File 'lib/latinum/resource.rb', line 57

def exchange(rate, name, precision = nil)
  exchanged_amount = @amount * rate
  
  exchanged_amount = exchanged_amount.round(precision) if precision
  
  self.class.new(exchanged_amount, name)
end

#inspect ⇒ Object 



69
70
71
 
# File 'lib/latinum/resource.rb', line 69

def inspect
  "<#{self.class.name} #{self.to_s.dump}>"
end

#to_s ⇒ Object 



65
66
67
 
# File 'lib/latinum/resource.rb', line 65

def to_s
  @amount.to_s('F') + ' ' + @name.to_s
end

#zero? ⇒ Boolean 



97
98
99
 
# File 'lib/latinum/resource.rb', line 97

def zero?
  @amount.zero?
end