Module: BinData::Float

Defined in:
lib/bindata/float.rb

Overview

Provides a number of classes that contain a floating point number. The float is defined by endian, and precision.

Class Method Summary collapse

Class Method Details

.create_float_methods(klass, single_precision, endian) ⇒ Object

:nodoc: all



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# File 'lib/bindata/float.rb', line 8

def self.create_float_methods(klass, single_precision, endian)
  read = create_read_code(single_precision, endian)
  to_s = create_to_s_code(single_precision, endian)

  define_methods(klass, single_precision, read, to_s)
end

.create_read_code(single_precision, endian) ⇒ Object 



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# File 'lib/bindata/float.rb', line 15

def self.create_read_code(single_precision, endian)
  if single_precision
    unpack = (endian == :little) ? 'e' : 'g'
    nbytes = 4
  else # double_precision
    unpack = (endian == :little) ? 'E' : 'G'
    nbytes = 8
  end

  "readbytes(io,#{nbytes}).unpack('#{unpack}').at(0)"
end

.create_to_s_code(single_precision, endian) ⇒ Object 



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# File 'lib/bindata/float.rb', line 27

def self.create_to_s_code(single_precision, endian)
  if single_precision
    pack = (endian == :little) ? 'e' : 'g'
  else # double_precision
    pack = (endian == :little) ? 'E' : 'G'
  end

  "[val].pack('#{pack}')"
end

.define_methods(klass, single_precision, read, to_s) ⇒ Object 



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# File 'lib/bindata/float.rb', line 37

def self.define_methods(klass, single_precision, read, to_s)
  nbytes = single_precision ? 4 : 8

  # define methods in the given class
  klass.module_eval <<-END
    def _num_bytes(ignored)
      #{nbytes}
    end

    #---------------
    private

    def sensible_default
      0.0
    end

    def val_to_str(val)
      #{to_s}
    end

    def read_val(io)
      #{read}
    end
  END
end