saxon:items-before
Returns the subsequence of the input ending with the item before the first item that matches the predicate.
items-before($input as item()*, $predicate as function(item()) as xs:boolean) ➔ item()*
Arguments | ||||
| $input | item()* | The input sequence | |
| $predicate | function(item()) as xs:boolean | Function determining the end condition | |
Result | item()* | |||
Namespace
http://saxon.sf.net/
Saxon availability
Requires Saxon-PE or Saxon-EE. Implemented since Saxon 10. Available for all platforms.
Notes on the Saxon implementation
Available from Saxon 10.
Details
This function returns a contiguous subsequence of the input sequence, starting at the
first item in the input, and ending with the item immediately before the first one that
matches the $predicate condition.
If no item in the input sequence matches the $predicate condition, the
entire input sequence is returned.
If the first item in the input sequence matches the $predicate condition,
the result is an empty sequence.
Example: saxon:items-before(1 to 20, function($x){$x mod 10 = 0}) returns
the sequence 1 to 9.
In XSLT, calls on saxon:items-before are streamable provided that the
function supplied as the predicate is either (a) a reference to a user-declared
stylesheet function declared with streamability="inspection", or (b) an
inline function whose body is grounded and motionless. More specifically, if the
predicate function satisfies these conditions then the posture and sweep of the function
call are the same as the posture and sweep of the first argument. Where possible,
reading and parsing of the source document will be abandoned when an item matching the
predicate is encountered.
Example: /*/emp => saxon:items-from(function($e){$e/@dept='sales'} =>
saxon:items-before(function($e){$e/@dept='QA'}