Package net.sf.saxon.pattern

Class PatternParser

java.lang.Object
net.sf.saxon.expr.parser.XPathParser
net.sf.saxon.pattern.PatternParser
public class PatternParser extends XPathParser
Parser for XSLT patterns. This is created by overriding selected parts of the standard ExpressionParser.

  • Constructor Details

  • Method Details

    • parsePattern

      public Pattern parsePattern(String pattern, StaticContext env) throws XPathException
      Parse a string representing an XSLT pattern
      Parameters:
      pattern - the pattern expressed as a String
      env - the static context for the pattern
      Returns:
      a Pattern object representing the result of parsing
      Throws:
      XPathException - if the pattern contains a syntax error

    • customizeTokenizer

      protected void customizeTokenizer(Tokenizer t)
      Callback to tailor the tokenizer
      Overrides:
      customizeTokenizer in class XPathParser
      Parameters:
      t - the Tokenizer to be customized

    • parseExpression

      public Expression parseExpression() throws XPathException
      Override the parsing of top-level expressions
      Overrides:
      parseExpression in class XPathParser
      Returns:
      the parsed expression
      Throws:
      XPathException - if the pattern is invalid

    • parseBasicStep

      protected Expression parseBasicStep(boolean firstInPattern) throws XPathException
      Parse a basic step expression (without the predicates)
      Overrides:
      parseBasicStep in class XPathParser
      Parameters:
      firstInPattern - true only if we are parsing the first step in a RelativePathPattern in the XSLT Pattern syntax
      Returns:
      the resulting subexpression
      Throws:
      XPathException - if any error is encountered

    • testPermittedAxis

      protected void testPermittedAxis(int axis, String errorCode) throws XPathException
      Overrides:
      testPermittedAxis in class XPathParser
      Throws:
      XPathException

    • parsePredicate

      protected Expression parsePredicate() throws XPathException
      Parse an expression appearing within a predicate. This enables full XPath parsing, without the normal rules that apply within an XSLT pattern
      Overrides:
      parsePredicate in class XPathParser
      Returns:
      the parsed expression that appears within the predicate
      Throws:
      XPathException - if the predicate is invalid

    • parseFunctionCall

      public Expression parseFunctionCall(Expression prefixArgument) throws XPathException
      Parse a function call appearing within a pattern. Unless within a predicate, this imposes the constraints on which function calls are allowed to appear in a pattern
      Overrides:
      parseFunctionCall in class XPathParser
      Parameters:
      prefixArgument - left hand operand of arrow operator, or null in the case of a conventional function call
      Returns:
      the expression that results from the parsing (usually a FunctionCall)
      Throws:
      XPathException - if the function call is invalid

    • parseFunctionArgument

      public Expression parseFunctionArgument() throws XPathException
      Description copied from class: XPathParser
      Parse an argument to a function call. Separate method so it can be overridden. With higher-order-function syntax in XPath 3.0/XQuery 3.0, this returns null if the pseudo-argument "?" is found.
      Overrides:
      parseFunctionArgument in class XPathParser
      Returns:
      the Expression used as the argument, or null if the argument is the place-holder "?"
      Throws:
      XPathException - if the argument expression does not parse correctly

    • makeTracer

      public Expression makeTracer(Expression exp, StructuredQName qName)
      Description copied from class: XPathParser
      If tracing, wrap an expression in a trace instruction

      NB, this no longer happens. Instead of creating trace expressions in the course of parsing and buildint the expression tree, trace code is now injected into the tree after the event, when parsing is complete. See ExpressionTool.injectCode(Expression, CodeInjector).

      However, the method has another effect, which is to set the retainedStaticContext in the node in the expression tree.

      Overrides:
      makeTracer in class XPathParser
      Parameters:
      exp - the expression to be wrapped
      qName - the name of the construct (if applicable)
      Returns:
      the expression that does the tracing