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Reference-Based Retrieval of Elements of a List

IP.com Disclosure Number: IPCOM000099364D
Original Publication Date: 1990-Jan-01
Included in the Prior Art Database: 2005-Mar-14
Document File: 3 page(s) / 110K

Publishing Venue

IBM

Related People

Tenner, JW: AUTHOR [+2]

Abstract

A Reference Based Retrieval (RBR) method allows elements in a list to be processed without knowing either the name or location of any of the elements in the list. The RBR interface allows the user to: 1) Access the "First" or "Last" element in the list. Neither the element name nor its location is needed. 2) Access the "Next" or "Previous" element in the list using a reference point, such as a previously accessed element name or location. If the reference point defines an element that does not exist, its logical position is used as the reference point. An access error occurs when there is no next or previous element to access. 3) Access the first element in the list whose name begins with a given character string.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 52% of the total text.

Reference-Based Retrieval of Elements of a List

       A Reference Based Retrieval (RBR) method allows elements
in a list to be processed without knowing either the name or location
of any of the elements in the list.  The RBR interface allows the
user to:  1) Access the "First" or "Last" element in the list.
Neither the element name nor its location is needed. 2) Access the
"Next" or "Previous" element in the list using a reference point,
such as a previously accessed element name or location.  If the
reference point defines an element that does not exist, its logical
position is used as the reference point.  An access error occurs when
there is no next or previous element to access.  3) Access the first
element in the list whose name begins with a given character string.
An access error occurs if no elements begin with the character
string, and 4) Save the name and/or location of the element accessed
so it can be used as a reference point for the next access.

      These various access methods can be combined to perform the
following:

      -  Access the "First" element in the list and progress forward

      through the list by repetitively accessing the "Next" element.

      -  Access the "Last" element in the list and progress backward
through the list by repetitively accessing the "Previous" element.

      -  Access the first element in the list whose name begins with
a character string and progress forward through the list by
repetitively accessing the "Next" element to get other elements that
may begin with the same string.

      An example of a user interface using the RBR method follows
this paragraph.  In this example, the elements are employees.  A
command named "GETEMPD" (Get Employee Description) is used to get an
employee's description. Following is a description of the parameters
for GETEMPD:

      1.  The employee whose description is requested is made up of
the first two parameters.

      a.  If the first parameter specifies an employee's name (it is
not preceded by a "*") and the second parameter is not *NEXT or
*PREVIOUS, the element's description is returned.

      b.  If the character string "*FIRST" is specified as the first
parameter, the description of the first employee in the list is
returned. (See Scenario 1.)

      c.  If the character string "*LAST" is specified as the first
parameter, the description of the last employee in the list is
returned.  (See Scenario 2.)

      d.  When "*FIRST" or "*LAST" is specified, the second parameter
is ignored.  (See Scenarios 1, 2, 3.)

      e.  If a name is specified for the first parameter and it ends
in a "*", the description of the first employee whose name begins
with the characters t...