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C H A P T E R 1 2
Special-Purpose Objects for Data Storage and Retrieval
12-8
Using Special-Purpose Data Storage Objects
You can use the
IsSameEntry
function to compare entries and aliases to each
other; this function returns
true
for any two aliases or references to the same
entry. For example:
// return entries that contain "bob" and "Apple"
local myCurs:= namesSoup:Query({ entireWords: true,
words:["Bob", "Apple"]});
local aBob:= myCurs:Entry();
// keep an alias to bob around
local bobAlias := MakeEntryAlias(aBob);
// the following comparison returns true
IsSameEntry(aBob, bobAlias)
The
IsEntryAlias
function returns
true
if its argument is an entry alias, as
shown in the following example:
// return entries that contain "bob" and "Apple"
local myCurs:= namesSoup:Query({ entireWords: true,
words:["Bob", "Apple"]});
// keep an alias to bob around
local bobAlias := MakeEntryAlias(myCurs:Entry());
// the following test returns true
IsEntryAlias(bobAlias);
Using Virtual Binary Objects
12
This section describes how to use a virtual binary object to store binary data that is
too large to fit into the NewtonScript heap. Topics discussed include:
creating compressed or uncompressed VBOs
saving VBOs in soup entries
adding data to VBOs
undoing changes to VBO data
In addition to the subjects discussed here, see "VBO Functions and Methods"
(page 9-74) in Newton Programmer's Reference for descriptions of VBO utility
functions.
Creating Virtual Binary Objects
12
When you create a VBO, you specify whether its associated binary data is to be
stored in compressed or uncompressed format. Whether you create compressed or
uncompressed VBO objects is a question of space versus speed: uncompressed
data provides faster access, but requires more store space than the equivalent
compressed data.
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