Class: Dentaku::DateArithmetic

Inherits:
Object
  • Object
show all
Defined in:
lib/dentaku/date_arithmetic.rb

Instance Method Summary collapse

Constructor Details

#initialize(date) ⇒ DateArithmetic

Returns a new instance of DateArithmetic.



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# File 'lib/dentaku/date_arithmetic.rb', line 3

def initialize(date)
  if date.respond_to?(:strftime)
    @base = date
  else
    @base = Time.parse(date).to_datetime
  end
end

Instance Method Details

#add(duration) ⇒ Object 



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# File 'lib/dentaku/date_arithmetic.rb', line 11

def add(duration)
  case duration
  when Numeric
    @base + duration
  when Dentaku::AST::Duration::Value
    case @base
    when Time
      change_datetime(@base.to_datetime, duration.unit, duration.value).to_time
    else
      change_datetime(@base, duration.unit, duration.value)
    end
  else
    raise Dentaku::ArgumentError.for(:incompatible_type, value: duration, for: Numeric),
      "'#{duration || duration.class}' is not coercible for date arithmetic"
  end
end

#sub(duration) ⇒ Object 



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# File 'lib/dentaku/date_arithmetic.rb', line 28

def sub(duration)
  case duration
  when Date, DateTime, Numeric, Time
    @base - duration
  when Dentaku::AST::Duration::Value
    case @base
    when Time
      change_datetime(@base.to_datetime, duration.unit, -duration.value).to_time
    else
      change_datetime(@base, duration.unit, -duration.value)
    end
  when Dentaku::TokenScanner::DATE_TIME_REGEXP
    @base - Time.parse(duration).to_datetime
  else
    raise Dentaku::ArgumentError.for(:incompatible_type, value: duration, for: Numeric),
      "'#{duration || duration.class}' is not coercible for date arithmetic"
  end
end