module Runt::TExpr

‘TExpr’ is short for ‘TemporalExpression’ and are inspired by the recurring event pattern[http://martinfowler.com/apsupp/recurring.pdf] described by Martin Fowler. Essentially, they provide a pattern language for specifying recurring events using set expressions.

Public Instance Methods

& (expr)

Source

# File lib/runt/temporalexpression.rb, line 56
def & (expr)
  self.and(expr){|adjusted| adjusted }
end

- (expr)

Source

# File lib/runt/temporalexpression.rb, line 60
def - (expr)
  self.minus(expr){|adjusted| adjusted }
end

| (expr)

Source

# File lib/runt/temporalexpression.rb, line 52
def | (expr)
  self.or(expr){|adjusted| adjusted }
end

and (arg) { |intersect.add(self).add(arg)| ... }

Source

# File lib/runt/temporalexpression.rb, line 38
def and (arg)

  if self.kind_of?(Intersect)
    self.add(arg)
  else
    yield Intersect.new.add(self).add(arg)
  end

end

dates (date_range, limit=0)

Source

# File lib/runt/temporalexpression.rb, line 69
def dates(date_range, limit=0)
  result = []
  date_range.each do |date|
    result << date if self.include? date
    if limit > 0 and result.size == limit
      break
    end
  end
  result
end

Contributed by Emmett Shear: Returns an Array of Date-like objects which occur within the supplied DateRange. Will stop calculating dates once a number of dates equal to the optional attribute limit are found. (A limit of zero will collect all matching dates in the date range.)

include? (date_expr)

Source

# File lib/runt/temporalexpression.rb, line 24
def include?(date_expr); false end

Returns true or false depending on whether this TExpr includes the supplied date expression.

minus (arg) { |diff| ... }

Source

# File lib/runt/temporalexpression.rb, line 48
def minus (arg)
    yield Diff.new(self,arg)
end

or (arg) { |union.add(self).add(arg)| ... }

Source

# File lib/runt/temporalexpression.rb, line 28
def or (arg)

  if self.kind_of?(Union)
    self.add(arg)
  else
    yield Union.new.add(self).add(arg)
  end

end

to_s ()

Source

# File lib/runt/temporalexpression.rb, line 26
def to_s; "TExpr" end