class Tins::Unit::UnitParser

def initialize(source, unit, prefixes = nil)
  super source
  if prefixes
    @unit_re    = unit_re(Tins::Unit.prefixes(prefixes), unit)
    @unit_lc_re = @unit_uc_re = nil
  else
    @unit_lc_re = unit_re(Tins::Unit.prefixes(:lc), unit)
    @unit_uc_re = unit_re(Tins::Unit.prefixes(:uc), unit)
    @unit_re    = nil
  end
  @number       = 1.0
end