Re: [xsl] Re: Will Saxon 9 optimize or cache this so performance doesn't degrade?

[Michael Kay <mike@xxxxxxxxxxxx>]

On 06/02/2013 08:09, Andrew Welch wrote:
> > What's a memo function?
> A function that will always return the same result for the same set of
> arguments.
>
> eg if you had a function that added 1 to a number, you can make it a
> memo function so the 2nd time it gets called with the same number, it
> will return the known previous result from a map, rather than compute
> it again.
More specifically a deterministic or pure function is one that will 
always return the same result for the same set of arguments. A memo 
function is one that takes advantage of this property by caching the 
result of previous evaluations. You can declare a function as a memo 
function in Saxon using the attribute saxon:memo-function="yes".

Michael Kay
Saxonica