Core schemas

• XMLDocument: document record with field root. The XML declaration is not stored.
• XMLAttribute: attribute record with fields name and value.
• XMLElement: element record with fields name, attributes, and children.
• XMLVALUE_ELEMENT and XMLVALUE_CHARDATA: tags for XMLValue.
• XMLValue: tagged child value that stores one child element or one character-data string.
• XMLParserResult: parse result with fields success, finished, errorInfo, and xml.
• XMLParserPosition: parser position with column, line, offset, currentSymbol, and currentCodepoint.
• XMLParserErrorInfo: error record with message and position.

XMLParserResult

• success: TRUE when lexical and structural parsing succeed and FALSE on invalid UTF-8 input or XML failure.
• finished: TRUE when the whole source is consumed after one successful document parse and FALSE when trailing input remains.
• errorInfo.message: parser failure description when success is FALSE.
• errorInfo.position: parser position at failure, or the first unparsed position when finished is FALSE.
• xml: parsed XMLDocument when success is TRUE. When finished is FALSE, it still contains the first parsed document.
• On invalid UTF-8 input, only errorInfo.position.offset is meaningful; line and column are not derived.

Parser model

• parseElementFromOpenTag: lower-level helper that parses one element after the opening < has already been consumed and the current parser position points to the first name character.
• parseStringToXMLImpl: lower-level helper underlying parseStringToXML. It parses one document from one already split UTF-8 source and one current parser position into supplied result objects.
• Attributes are stored in parse order, duplicate attribute names make parsing fail, and whitespace-only character data is discarded.
• The parser accepts one document root element, attributes, comments, character data, and one optional XML declaration.
• Comments are skipped and are not stored. The XML declaration is parsed when present but is not stored in XMLDocument.
• Named references handled by the module are &, >, <, and ".
• ', numeric character references, document type declarations, CDATA sections, and processing instructions in element content are unsupported.
• Known source text can be parsed during compilation, and compile-time code can inspect root names, attribute counts, and child counts of the resulting tree.

parseStringToXML (source -- result)

Parses one accepted UTF-8 source into XMLParserResult.

• Accepted source forms are StringView, Text, and String.
• The source is normalized through String.makeStringView before UTF-8 splitting begins.
• The result fields are described in XMLParserResult.

saveXMLToString (xml -- string)

Serializes one XMLDocument to a formatted String.

• Element names and attributes are written in stored order.
• Child elements are indented by two spaces per depth level.
• Character data is emitted inline inside the parent element content.
• The serializer emits the stored XMLElement tree only; the XML declaration and comments are not re-emitted.
• The serializer does not escape character data or attribute values, so stored names and data must already be suitable for direct emission.

Examples

Successful parse and stored counts

"Xml"     use
"control" use

{} () {} [
  result: "<root a=\"b\"><child/></root>" parseStringToXML;
  @result.@success TRUE same printStack _:;
  @result.@finished TRUE same printStack _:;
  @result.@xml.@root.@attributes.size 1 same printStack _:;
  @result.@xml.@root.children.size 1 same printStack _:;
] "main" exportFunction

Expected Output During Compilation

TRUE
TRUE
TRUE
TRUE

Trailing input, duplicate attribute, discarded whitespace-only child data, and unsupported reference

"Xml"     use
"control" use

{} () {} [
  trailing: "<root/>x" parseStringToXML;
  @trailing.@success TRUE same printStack _:;
  @trailing.@finished FALSE same printStack _:;

  duplicate: "<root a=\"1\" a=\"2\"/>" parseStringToXML;
  @duplicate.@success FALSE same printStack _:;

  spaces: "<root>   </root>" parseStringToXML;
  @spaces.@xml.@root.children.size 0 same printStack _:;

  apos: "<root>'</root>" parseStringToXML;
  @apos.@success FALSE same printStack _:;
] "main" exportFunction

Expected Output During Compilation

TRUE
TRUE
TRUE
TRUE
TRUE

Runtime example

"String"  use
"Xml"     use
"control" use

{} Int32 {} [
  result: "<root a=\"b\"><child/></root>" parseStringToXML;
  ("success=" result.success LF
    "finished=" result.finished LF
    "attrs=" result.xml.root.attributes.size LF
    "children=" result.xml.root.children.size LF) printList
  0
] "main" exportFunction

Expected Output

success=TRUE
finished=TRUE
attrs=1
children=1

See also

• String: UTF-8 string views, owned strings, formatting helpers, and text conversion utilities.
• Json: JSON value type, parsing helpers, and serialization helpers.