Name
every — Returns true if all items of given sequence matches given criterion.
Synopsis
boolean
every
(
|
varname string , |
| test_set sequence , | |
test_expn
boolean
); |
Description
The function creates a temporary local variable, whose name is specified by
varname
argument.
Then, for every item of test_set
sequence it
calculates the test_expn
boolean expression
having set the created variable to that "current" item.
If the value of expression is false, the function immediately returns
false without processing the rest of test_set
sequence.
If all items of the sequence are probed without getting false,
true is returned. (So if the sequence is empty, the function returns true).
In any case, temporary variable is destroyed on return.
This function is used in the implementation of "EVERY" logical operator in XQUERY, so you will probably use that operator in XQUERY expressions, not the function. This function may be useful in XPATH expressions and in XSLT stylesheets. It is not a part of library of standard XQUERY 1.0 functions.
Parameters
varname
Name of temporary variable
test_set
Sequence of items; these items will be tested by
test_expn
test_expn
Boolean expression which should be calculated for items of
test_set
.
Return Types
Boolean
Examples
Example 24.585.
This expression returns true if all reports have positive incomes recorded.
every('income_value', /report/income, $income_value > 0)