Method: Interval#each

Defined in:

lib/standard/facets/interval.rb

#each(n = nil, d = nil) ⇒ Object

TODO:

Deprecate arguments and simplify each definition accordingly.

Iterates over the interval, passing each _n_th element to the block. If n is not given then n defaults to 1. Each _n_th step is determined by invoking + or \- n, depending on the direction of the interval. If n is negative the iteration is preformed in reverse form end sentinal to front sentinal. A second parameter, d, can be given in which case the applied step is calculated as a fraction of the interval’s length times n / d. This allows iteration over the whole interval in equal sized segments.

1..5.each { |e| ... }        #=> 1 2 3 4 5
1..5.each(2) { |e| ... }     #=> 1 3 5
1..5.each(1,2) { |e| ... }   #=> 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0

# File 'lib/standard/facets/interval.rb', line 193

def each(n=nil, d=nil)  # :yield:
  if n
    warn "FACETS: `interval.each(n,d){...}` will be deprecated.\n" +
         "Use `interval.step(n,d).each{...}` instead."
  else
    n = 1
  end

  return (n < 0 ? @last : @first) if degenerate?  # is this right for all values of n ?

  s = d ? self.length.to_f * (n.to_f / d.to_f) : n.abs
  raise "Cannot iterate over zero length steps." if s == 0
  s = s * @direction
  if n < 0
    e = @exclude_last ? @last - s : @last
    #e = @exclude_last ? @last.pred(s) : @last
    t = @exclude_last ? 1 : 0
    #while e.cmp(@first) >= t
    while (e <=> @first) >= t
      yield(e)
      e -= s
      #e = e.pred(s)
    end
  else
    e = @exclude_first ? @first + s : @first
    #e = @exclude_first ? @first.succ(s) : @first
    t = @exclude_last ? -1 : 0
    #while e.cmp(@last) <= t
    while (e <=> @last) <= t
      yield(e)
      e += s
      #e = e.succ(s)
    end
  end
end