com.saxonica.bytecode
Class ToBooleanCompiler

java.lang.Object
  com.saxonica.bytecode.ExpressionCompiler
      com.saxonica.bytecode.ToBooleanCompiler

Direct Known Subclasses:

AndExpressionCompiler, BooleanFnCompiler, CastableExpressionCompiler, CastableToListCompiler, CastableToUnionCompiler, CompareToIntegerConstantCompiler, ContainsCompiler, DocAvailableCompiler, EmptyCompiler, EquivalenceComparisonCompiler, ExistsCompiler, GeneralComparisonCompiler, IndexedLookupExpressionCompiler, InstanceOfCompiler, IntegerRangeTestCompiler, IsLastExpressionCompiler, IsWholeNumberCompiler, MatchesCompiler, NotFnCompiler, OrExpressionCompiler, QuantifiedExpressionCompiler, StartsWithCompiler, ValueComparisonCompiler

public abstract class ToBooleanCompiler
extends ExpressionCompiler

Abstract superclass for expression compilers that handle boolean expressions, that is, expressions that return a boolean result. Compilers for such expressions must implement the compileToBoolean method; other methods such as compileToItem and compileToIterator invoke the compileToBoolean method.

Constructor Summary

ToBooleanCompiler()

Method Summary

void	compileToItem(CompilerService compiler, Expression expression) Generate bytecode to evaluate the expression as an Item Precondition: none.
void	compileToIterator(CompilerService compiler, Expression expression) Generate bytecode to evaluate the expression as a SequenceIterator Precondition: none.
void	compileToPush(CompilerService compiler, Expression expression) Generate bytecode to evaluate the expression in push mode Precondition: none.

Methods inherited from class com.saxonica.bytecode.ExpressionCompiler

allocateStatic, compileItemFromInt, compileItemFromString, compileToBoolean, compileToLoop, compileToPrimitive, generateMethod, getConfiguration, handleEmptyStringResult, setConfiguration, throwXPathException, throwXPathException, unboxItem, verify, visitAnnotation, visitLineNumber

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

ToBooleanCompiler

public ToBooleanCompiler()

Method Detail

compileToItem

public void compileToItem(CompilerService compiler,
                          Expression expression)
                   throws CannotCompileException

Description copied from class: ExpressionCompiler

Generate bytecode to evaluate the expression as an Item Precondition: none. Postcondition: at execution time, the stack contains either an item (the result of the expression), or null (representing an empty sequence).

Specified by:

compileToItem in class ExpressionCompiler

Parameters:

compiler - the compiler service

expression - the expression to be compiled

Throws:

CannotCompileException

compileToIterator

public void compileToIterator(CompilerService compiler,
                              Expression expression)
                       throws CannotCompileException

Description copied from class: ExpressionCompiler

Generate bytecode to evaluate the expression as a SequenceIterator Precondition: none. Postcondition: at execution time, the stack contains a SequenceIterator representing the result of the expression

Specified by:

compileToIterator in class ExpressionCompiler

Parameters:

compiler - the compiler service

expression - the expression to be compiled

Throws:

CannotCompileException

compileToPush

public void compileToPush(CompilerService compiler,
                          Expression expression)
                   throws CannotCompileException

Description copied from class: ExpressionCompiler

Generate bytecode to evaluate the expression in push mode Precondition: none. Postcondition: at execution time, the stack is unchanged, and the value of the expression has been written to the current receiver

Specified by:

compileToPush in class ExpressionCompiler

Parameters:

compiler - the compiler service

expression - the expression to be compiled

Throws:

CannotCompileException