Module: Units::UseBlocks

Included in:
Units
Defined in:
lib/units-system.rb

Overview

This must be included in any module or class from which units expressions are to be used in units or u blocks. It is not needed in Ruby 1.9.1 due to they way constant look-up is done in that version, but Ruby 1.9.2 has changed that an requires this again.

Constant Summary collapse

@@constants =

an instance variable would not work here because const_missing is executed on other modules (which include this one)

nil

Class Method Summary collapse

Class Method Details

.append_features(target) ⇒ Object 



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# File 'lib/units-system.rb', line 17

def self.append_features(target)
  def target.const_missing(name)
    begin
      name = name.to_sym
      if name==:Const
        Units::Const
      else
        result = @@constants[name] if @@constants
        result || Units.Measure(name)
      end
    rescue ArgumentError
      super
    end
  end
end

.with_constants(*consts) ⇒ Object 



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# File 'lib/units-system.rb', line 33

def self.with_constants(*consts)
  prev = @@constants
  # @@constants = consts.map_hash{|c| Units.constant(c)}
  @@constants = {}
  consts.each do |c|
    c = c.to_sym
    @@constants[c] = Units.constant(c)
  end
  result = yield
  @@constants = prev
  result
end