PhoenixmlDb.XQuery

XQueryParserFacade

Public API for parsing XQuery 3.1 source text into an abstract syntax tree (AST).

#XQueryParserFacade

Namespace: PhoenixmlDb.XQuery.Parser

Public API for parsing XQuery 3.1 source text into an abstract syntax tree (AST).

This class provides two parsing strategies:

• XQueryParserFacade.Parse — throws XQueryParseException on syntax errors. Use when you expect valid input and want fail-fast behavior.

• XQueryParserFacade.TryParse — returns null on failure and populates an error list. Use for IDE-style validation or when you want to report all errors without exceptions.

The returned XQueryExpression AST can be inspected, transformed, or passed directly to QueryEngine.Compile for compilation and execution. This is useful for syntax validation without execution, AST-level transformations, or building tooling such as formatters and linters.

#Example

Parse and validate syntax:

var parser = new XQueryParserFacade();
if (parser.TryParse("for $x in (1,2,3) return $x * 2", out var errors) is { } ast)
    Console.WriteLine("Valid XQuery");
else
    foreach (var error in errors)
        Console.Error.WriteLine($"Line {error.Line}: {error.Message}");
                                  

#Properties

#Methods

#Parse(String)

Parses an XQuery expression string into an AST, throwing on any syntax error.

Parameters:

• xquery — The XQuery source text. Must not be null.

Returns: The root XQueryExpression node of the parsed AST.

Exceptions:

• ArgumentNullException — Thrown when xquery is null.

• XQueryParseException — Thrown when the input contains one or more syntax errors. The XQueryParseException.Errors property contains location details.

See also: XQueryParserFacade.TryParse

#TryParse(String,Collections.Generic.IReadOnlyList<PhoenixmlDb.XQuery.Parser.ParseError>@)

Attempts to parse an XQuery expression without throwing on syntax errors.

Parameters:

• xquery — The XQuery source text.

• errors — When the method returns null, contains one or more ParseError instances with location details. Empty on success.

Returns: The parsed AST on success, or null if parsing failed.

Unlike

, this method never throws for syntax errors. It returns

null

and populates

with all parse errors including line and column information. This is the preferred method for interactive validation scenarios.

See also: XQueryParserFacade.Parse

#Fields