Module: IntervalNotation::BasicIntervals

Defined in:
lib/interval_notation/basic_intervals.rb

Overview

:nodoc: all

Defined Under Namespace

Modules: ActslikeInterval Classes: BoundaryPoint, ClosedClosedInterval, ClosedOpenInterval, OpenClosedInterval, OpenOpenInterval, Point

Constant Summary collapse

PLUS_INFINITY_VARIANTS = 
['∞', 'inf', 'infinity', 'infty', '\infty', '+∞', '+inf', '+infinity', '+infty', '+\infty']
MINUS_INFINITY_VARIANTS = 
['-∞', '-inf', '-infinity', '-infty', '-\infty']
EMPTY_VARIANTS = 
['∅','empty','']
OPENING_VARIANTS = 
['(','[']
CLOSING_VARIANTS = 
[')',']']

Class Method Summary collapse

Class Method Details

.from_string(interval_str) ⇒ Object

returns an Interval (wrapped or unwrapped) or an array of Points or empty list (for Empty interval)



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# File 'lib/interval_notation/basic_intervals.rb', line 222

def self.from_string(interval_str)
  interval_str = interval_str.gsub(/\s/,'')
  return Empty  if EMPTY_VARIANTS.include?(interval_str.downcase)
  return R  if interval_str == 'R'
  if interval_str[0] == '{' && interval_str[-1] == '}'
    interval_str[1..-2].split(/[,;]/).map{|el| Point.new(Float(el)) }
  elsif OPENING_VARIANTS.include?(interval_str[0]) && CLOSING_VARIANTS.include?(interval_str[-1])
    boundary_values = interval_str[1..-2].split(/[,;]/).map(&:strip)
    raise Error, 'Unknown format'  unless boundary_values.size == 2
    from = (MINUS_INFINITY_VARIANTS.include?(boundary_values[0].downcase)) ? -Float::INFINITY : Float(boundary_values[0])
    to   = (PLUS_INFINITY_VARIANTS.include?(boundary_values[1].downcase)) ? Float::INFINITY : Float(boundary_values[1])

    if interval_str[0] == '('
      if interval_str[-1] == ')'
        OpenOpenInterval.new(from, to)
      elsif interval_str[-1] == ']'
        OpenClosedInterval.new(from, to)
      else
        raise Error, 'Unknown format'
      end
    elsif interval_str[0] == '['
      if interval_str[-1] == ')'
        ClosedOpenInterval.new(from, to)
      elsif interval_str[-1] == ']'
        ClosedClosedInterval.new(from, to)
      else
        raise Error, 'Unknown format'
      end
    else
      raise Error, 'Unknown format'
    end
  else
    begin
      Point.new(Float(interval_str))
    rescue
      raise Error, 'Unknown format'
    end
  end
end

.interval_by_boundary_inclusion(include_from, from, include_to, to) ⇒ Object 



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# File 'lib/interval_notation/basic_intervals.rb', line 195

def self.interval_by_boundary_inclusion(include_from, from, include_to, to)
  if include_from
    if include_to
      if from != to
        ClosedClosedInterval.new(from, to)
      else
        Point.new(from)
      end
    else
      ClosedOpenInterval.new(from, to)
    end
  else
    if include_to
      OpenClosedInterval.new(from, to)
    else
      OpenOpenInterval.new(from, to)
    end
  end
end