Class: MadderLib::Conditional::Helper::TestBlock

Inherits:
Object
  • Object
show all
Defined in:
lib/madderlib/conditional/helper.rb

Constant Summary collapse

FALSE = 
lambda { false }
ONE = 
lambda { 1 }

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(*args, &block) ⇒ TestBlock

Returns a new instance of TestBlock.



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# File 'lib/madderlib/conditional/helper.rb', line 11

def initialize(*args, &block)
  if block
    # if we get a block, use it!
    raise Error, 'block AND args provided, requires one or the other' if (args && (! args.empty?))
    raise Error, 'block arity should be 0; 1 (count) or; 2 (count, Context)' if (block.arity > 2)

    # it will remain unchanging
    @criteria = block
  else
    # leave the originals alone
    args = args.clone

    begin
      #  how does it start?
      arg = args.shift

      if Range === arg
        # we received a Range
        @criteria = arg
      elsif arg.respond_to?(:integer?) && arg.integer?
        upper = args.first
        if upper && upper.respond_to?(:integer?) && upper.integer?
          #  we can make a Range from that
          @criteria = Range.new(arg, args.shift)
        else
          #  just a count
          @criteria = arg
        end
      else
        raise Error, "invalid test block argument : #{arg.inspect}"
      end
    rescue Error => e
      raise e
    rescue Exception => e
      #  wrap
      raise e
      raise Error.new("invalid test block argument : #{arg.inspect}", e)
    end

    # beyond that, is there a unit?
    #   we deal with all of that during build
    @units = args.shift
  end
end

Instance Attribute Details

#criteria ⇒ Object (readonly)

Returns the value of attribute criteria.



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# File 'lib/madderlib/conditional/helper.rb', line 9

def criteria
  @criteria
end

Instance Method Details

#block ⇒ Object 



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# File 'lib/madderlib/conditional/helper.rb', line 58

def block
  if Proc === @criteria
    # the block will do its own testing
    @criteria
  elsif Range === @criteria
    # we'll stop somewhere in that range
    #   note that it's inclusive
    #   if the caller says '2 .. 4', 4 should be a possibility
    limit = unitize(@criteria.rand_inclusive)
    lambda {|count| count < limit }
  elsif @criteria.integer?
    limit = unitize(@criteria)
    lambda {|count| count < limit }
  else
    # never will succeed
    FALSE
  end
end

#invoke(*args, &given_block) ⇒ Object 



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# File 'lib/madderlib/conditional/helper.rb', line 77

def invoke(*args, &given_block)
  #  take in a block, or use the internally held one
  #    allows for external buffering
  b = block_given? ? given_block : self.block
  p = args

  if b.arity < 1
    # how interesting!  arity of -1
    b.call
  else
    # only as many args as supported
    #   do not worry about shortfall; that'll be a failure
    p.pop while b.arity < p.size
    b.call *p
  end
end

#to_i(context) ⇒ Object 



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# File 'lib/madderlib/conditional/helper.rb', line 96

def to_i(context)
  value = nil

  if Proc === @criteria
    value = MadderLib::Context.invoke(@criteria, context)
  elsif Range === @criteria
    value = @criteria.max
  elsif @criteria.integer?
    value = @criteria
  end

  #  has to be an integer, by definition
  if value && value.respond_to?(:integer?) && value.integer?
    unitize(value)
  else
    nil
  end
end