Class: ModuloNumber (private in Integer

• Inheritance
• Description
• Related information
• Class protocol
  • instance creation
• Instance protocol
  • accessing
  • arithmetic
  • converting
• Examples

Inheritance:

   Object
   |
   +--Integer::ModuloNumber

Package:

stx:libbasic

Category:

Magnitude-Numbers

Owner:

Integer

Author:

Stefan Vogel

Description:

This is a helper class to perform fast computation of the modulus.
(with big numbers, this does make a difference)

WARNING: this does only work with numbers which have no common
         divisor (which is true for cryptographic applications).
         So, use this only if you know what you are doing ...



[instance variables:]
    modulus       the modulus
    reciprocal    reciprocal of the modulus
    shift         shift count to cut off some bits

Related information:

    Integer
    SmallInteger
    LargeInsteger

Class protocol:

 modulus: anInteger

Instance protocol:

 modulus

return the modulus

 modulus: n

set the modulus

 modulusOf: aNumber

compute the aNumber modulo myself.
The shortcut works only, if aNumber is < modulo * modulo
(When doing arithmethic modulo something).
Otherwise do it the long way

 asModuloNumber

Examples:

        17 asModuloNumber modulusOf:38

        38 \\ 17