op:call

op:call() as map:map

Summary

This function calls value processing built-in functions that aren't listed in the list Value Processing Functions, the API also provides a general-purpose constructor for deferred calls.

Use this function with care because some builtins could adversely affect performance or worse. The following restrictions apply to the use of the op.call function:

• Call only MarkLogic built-in functions. You cannot call SJS or XQY functions using this function. Instead, use a map or reduce function to postprocess the results.
• Do not call update functions, such as xdmp:document-insert
• Do not call side effect functions, such as xdmp:forest-clear

Example

xquery version "1.0-ml";

import module namespace op="http://marklogic.com/optic"
     at "/MarkLogic/optic.xqy";

op:from-view("main", "employees")
	   => op:select(("EmployeeID",  
                op:as("callcheck", 
                      op:call("http://www.w3.org/2005/xpath-functions", 
                              "concat", 
                              json:to-array((op:col("EmployeeID"), "_x"))
	              ))))
	   => op:result()