Jackson Method Definition/Meaning:
A proprietary brand of structured programming, developed by
the British consultant Michael Jackson specifically for use in
data processing.
He observed that the inputs and outputs of programs could be defined in terms of
particular data structures, which are mostly static and easier to define than
programs. He then proposed that programs should be constructed by a systematic
method based on data structure diagrams. Two main problems arise.
First, it may
not be possible to combine the separate data structure diagrams involved in a
program because of what are called structure clashes; this is solved by a form
of program decomposition called inversion.
Second, error handling is not
accommodated by the simple method, and gives rise to a technique called
backtracking, which is
programmed by using assertions and the notation posit/quit/admit.
Jackson
method is used in conjunction with Cobol and PL/I. Translators exist to convert
from textual equivalents of Jackson data-structure diagrams into the required
target language. It is claimed that the same code will always be produced from a
given data specification.
|
