XSLT3 Issue with Lookup Value | Streaming - xslt

Question

I have a merged report data(data comes from two sources)as an input file and I needed to lookup a value based on a key. Currently my code is returning incorrectly looking up values. Since the size of the input data is expected to be large, I would like to use streaming for better performance.
Here is my input xml
Element Number'is the key to lookup. Xpath is 'Batch/Workers/Number`
Lookup Phone element based on Number' . Xpath isMergedOutput/Data/Row/Phone`
Sample Input
<?xml version="1.0" encoding="UTF-8"?>
<MergedOutput>
<Data>
<Row>
<Employee_Batch_Id>12567</Employee_Batch_Id>
<Phone>FirstEmp8013457896</Phone>
<Assignment_Id>5046150263</Assignment_Id>
</Row>
<Row>
<Employee_Batch_Id>12568</Employee_Batch_Id>
<Phone>SecondEmp7853457896</Phone>
<Assignment_Id>5046150263</Assignment_Id>
</Row>
</Data>
<Batch>
<Workers>
<Number>12567</Number>
<Contact>Work7864532890</Contact>
</Workers>
<Workers>
<Number>12568</Number>
<Contact>Work6782340167</Contact>
</Workers>
</Batch>
</MergedOutput>
Current XSLT3 code
<?xml version="1.0" encoding="UTF-8"?>
<xsl:stylesheet xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
xmlns:xs="http://www.w3.org/2001/XMLSchema"
xmlns:map="http://www.w3.org/2005/xpath-functions/map"
exclude-result-prefixes="xs r1 r2 map"
version="3.0">
<xsl:output method="xml" indent="yes"/>
<xsl:mode streamable="yes" on-no-match="shallow-skip" use-accumulators="#all"/>
<xsl:accumulator name="FirstReportLookupValuePhone" as="xs:string" initial-value="''" streamable="yes">
<xsl:accumulator-rule match="Phone/text()" select="."/>
</xsl:accumulator>
<xsl:accumulator name="EmployeeIDLookup" as="map(xs:string,xs:string)" initial-value="map{}" streamable="yes">
<xsl:accumulator-rule match="Employee_Batch_Id/text()" select="map:put($value, string(.), accumulator-before('FirstReportLookupValuePhone'))"/>
</xsl:accumulator>
<xsl:template match="Batch">
<Workers>
<xsl:apply-templates select="Workers"/>
</Workers>
</xsl:template>
<xsl:template match="Workers">
<xsl:variable name="vWorkers" select="copy-of()"/>
<xsl:variable name="vMappedWorker" select="accumulator-after('EmployeeIDLookup')( normalize-space($vWorkers/Number))"/>
<Worker>
<WorkerID><xsl:value-of select="$vWorkers/Number"/></WorkerID>
<Work_Contact_Number><xsl:value-of select="$vWorkers/Contact"/></Work_Contact_Number>
<Home_Contact_Number><xsl:value-of select="$vMappedWorker"/></Home_Contact_Number>
</Worker>
</xsl:template>
</xsl:stylesheet>
Current output
<?xml version="1.0" encoding="UTF-8"?>
<Workers>
<Worker>
<WorkerID>12567</WorkerID>
<Work_Contact_Number>Work7864532890</Work_Contact_Number>
<Home_Contact_Number/> <!-- Value is empty, Expected value is FirstEmp8013457896 -->
</Worker>
<Worker>
<WorkerID>12568</WorkerID>
<Work_Contact_Number>Work6782340167</Work_Contact_Number>
<Home_Contact_Number>FirstEmp8013457896</Home_Contact_Number> <!-- Incorrect Value, Expected value is SecondEmp7853457896 -->
</Worker>
</Workers>
Expected Output
<?xml version="1.0" encoding="UTF-8"?>
<Workers>
<Worker>
<WorkerID>12567</WorkerID>
<Work_Contact_Number>Work7864532890</Work_Contact_Number>
<Home_Contact_Number>FirstEmp8013457896</Home_Contact_Number>
</Worker>
<Worker>
<WorkerID>12568</WorkerID>
<Work_Contact_Number>Work6782340167</Work_Contact_Number>
<Home_Contact_Number>SecondEmp7853457896</Home_Contact_Number>
</Worker>
</Workers>
Please could someone help me figure out how could i get the desired output?

Answer 1

The problem is that the accumulator matching Employee_Batch_ID tries to use the accumulator value for Phone; but because the Employee_Batch_ID appears before the Phone element, the Phone accumulator value isn't available yet.
I think you have to reverse the logic: when you encounter an Employee_Batch_ID/text(), save the ID value as a string in accumulator A; when you encounter a Phone/text(), add an ID=phone entry to a map held in Accumulator B.