Class: EyeOfNewt::Units

Inherits:
Object
  • Object
show all
Defined in:
lib/eye_of_newt/units.rb

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize ⇒ Units

Returns a new instance of Units.



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# File 'lib/eye_of_newt/units.rb', line 7

def initialize
  @units = {}
  @conversions = Hash.new { |h, k| h[k] = {} }
  @unit_modifiers = []
  @default = nil
  @unquantified = []
end

Instance Attribute Details

#conversions ⇒ Object (readonly)

Returns the value of attribute conversions.



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# File 'lib/eye_of_newt/units.rb', line 5

def conversions
  @conversions
end

#default ⇒ Object (readonly)

Returns the value of attribute default.



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# File 'lib/eye_of_newt/units.rb', line 5

def default
  @default
end

#unit_modifiers ⇒ Object (readonly)

Returns the value of attribute unit_modifiers.



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# File 'lib/eye_of_newt/units.rb', line 5

def unit_modifiers
  @unit_modifiers
end

#units ⇒ Object (readonly)

Returns the value of attribute units.



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# File 'lib/eye_of_newt/units.rb', line 5

def units
  @units
end

Class Method Details

.defaults ⇒ Object 



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# File 'lib/eye_of_newt/units.rb', line 63

def self.defaults
  new.setup do
    # english volume units
    add_unit "cups", "c.", "c", "cup"
    add_unit "fl oz", "fl. oz.", "fluid ounces", "fluid ounce"
    add_unit "gallons", "gal", "gal.", "gallon"
    add_unit "pints", "pt", "pt.", "pint"
    add_unit "quarts", "qt", "qt.", "qts", "qts.", "quart"
    add_unit "tbsp", "tbsp.", "T", "T.", "tbs.", "tbs", "tablespoons", "tablespoon"
    add_unit "tsp", "tsp.", "t", "t.", "teaspoons", "teaspoon"

    # english mass units
    add_unit "lb", "lb.", "pounds", "pound"
    add_unit "oz", "oz.", "ounces", "ounce"

    # metric volume units
    add_unit "l", "l.", "liter", "liters", "litre", "litres"
    add_unit "ml", "ml.", "milliliter", "milliliters", "millilitre", "millilitres"

    # metric mass units
    add_unit "kg", "kg.", "kilogram", "kilograms"
    add_unit "g", "g.", "gr", "gr.", "gram", "grams"
    add_unit "mg", "mg", "mg.", "milligram", "milligrams"

    # nonstandard units
    add_unit "pinches", "pinch"
    add_unit "dashes", "dash"
    add_unit "touches", "touch"
    add_unit "handfuls", "handful"
    add_unit "cloves", "clove"
    add_unit "bunches", "bunch"
    add_unit "sprigs", "sprig"
    add_unit "cans", "can"

    add_unit_modifier "big"
    add_unit_modifier "large"
    add_unit_modifier "medium"
    add_unit_modifier "small"
    add_unit_modifier "heaping"
    add_unit_modifier "level"

    # unquantified units
    add_unit "to taste", unquantified: true

    add_unit "units", "unit", default: true

    add_conversion 16, "tbsp", "cup"
    add_conversion 8, "fl oz", "cup"
    add_conversion 235, "ml", "cup"
    add_conversion 4, "quarts", "gallon"
    add_conversion 2, "cups", "pint"
    add_conversion 2, "pints", "quart"
    add_conversion 3, "tsp", "tbsp"

    add_conversion 16, "oz", "pound"
    add_conversion 454, "grams", "pound"

    add_conversion 1000, "ml", "liter"

    add_conversion 1000, "g", "kg"
    add_conversion 1000, "mg", "g"
  end
end

Instance Method Details

#[](unit) ⇒ Object 



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# File 'lib/eye_of_newt/units.rb', line 19

def [](unit)
  units[unit] or raise UnknownUnit.new(unit)
end

#add_conversion(amount, unit, other_unit) ⇒ Object 



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# File 'lib/eye_of_newt/units.rb', line 35

def add_conversion(amount, unit, other_unit)
  unit = self[unit]
  other_unit = self[other_unit]

  new_conversion = {unit => {other_unit => amount.to_r}, other_unit => {unit => 1/amount.to_r}}
  conversions.deep_merge!(new_conversion)
end

#add_unit(canonical, *variations, default: false, unquantified: false) ⇒ Object 



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# File 'lib/eye_of_newt/units.rb', line 23

def add_unit(canonical, *variations, default: false, unquantified: false)
  units[canonical] = canonical
  variations.each do |v|
    units[v] = canonical
  end

  @unquantified << canonical if unquantified
  @default = canonical if default

  conversions[canonical][canonical] = 1
end

#add_unit_modifier(modifier) ⇒ Object 



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# File 'lib/eye_of_newt/units.rb', line 43

def add_unit_modifier(modifier)
  unit_modifiers << modifier
end

#all ⇒ Object 



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# File 'lib/eye_of_newt/units.rb', line 15

def all
  units.keys
end

#conversion_rate(from, to) ⇒ Object 



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# File 'lib/eye_of_newt/units.rb', line 47

def conversion_rate(from, to)
  f = self[from]
  t = self[to]
  r = search_conversion(f, t) or raise UnknownConversion.new(from, to)
  r.to_f
end

#setup(&block) ⇒ Object 



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# File 'lib/eye_of_newt/units.rb', line 58

def setup(&block)
  instance_eval &block
  self
end

#unquantified?(unit) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/eye_of_newt/units.rb', line 54

def unquantified?(unit)
  @unquantified.include?(self[unit])
end