feat: implement XML parsing utilities and diagnostics for improved error handling

[CaiJimmy]

XML inputs are now parsed through one helper, XmlParsingUtils, so every entry point reports parse errors the same way:

Unable to parse <input> at line L, column C: <parser reason>

Previously each of fn:doc, fn:doc-available, fn:parse-xml, fn:parse-xml-fragment, jn:xml-files and serialization parameter documents created its own parser, and only fn:doc reported the position and reason.

Behavior changes

• jn:xml-files raises FODC0002 naming the file and position, instead of a generic RuntimeException whose message contained the whole file. It also keeps the file's line breaks, so reported lines are correct.
• fn:parse-xml and fn:parse-xml-fragment include the parser's reason and the position in the input (FODC0006, unchanged). Fragment positions are relative to the argument, not the internal wrapper element.
• Serialization parameter documents report the file and position.
• fn:doc-available and the parse functions no longer print parser errors to stderr.

Error metadata still points to the call in the query; the position inside the XML is part of the message. Apart from jn:xml-files, error codes are unchanged.

[github-actions]

QT3 Test Results - Parser: jsoniq

Regression baseline: run 37794943109

🎉 No regressions found for this build.

Summary of passed tests for jsoniq

Test Suite	Passing	Failing	Errors	Skipped	Missing features	Total
app	2037	27	88	5	5	2157
array	208	0	1	0	0	209
fn	10308	270	170	387	315	11135
map	220	0	0	0	0	220
math	149	0	0	0	0	149
misc	764	34	21	52	18	871
op	4339	4	23	0	0	4366
prod	11469	343	187	208	7	12207
ser	332	11	0	0	0	343
xs	155	0	0	9	0	164
Total	29981	689	490	661	345	31821

Full analysis report: see analysis-jsoniq in artifacts.

Download detailed test results

[github-actions]

QT3 Test Results - Parser: xquery

Regression baseline: run 37794943109

🎉 No regressions found for this build.

Summary of passed tests for xquery

Test Suite	Passing	Failing	Errors	Skipped	Missing features	Total
app	2044	26	82	5	5	2157
array	209	0	0	0	0	209
fn	10330	249	169	387	315	11135
map	220	0	0	0	0	220
math	149	0	0	0	0	149
misc	768	30	21	52	18	871
op	4339	4	23	0	0	4366
prod	11550	295	154	208	7	12207
ser	343	0	0	0	0	343
xs	155	0	0	9	0	164
Total	30107	604	449	661	345	31821

Full analysis report: see analysis-xquery in artifacts.

Download detailed test results