com.saxonica.bytecode
Class SimpleStepExpressionCompiler

java.lang.Object
  com.saxonica.bytecode.ExpressionCompiler
      com.saxonica.bytecode.ToIteratorCompiler
          com.saxonica.bytecode.SimpleStepExpressionCompiler

public class SimpleStepExpressionCompiler
extends ToIteratorCompiler

Generate bytecode for a call to the SimpleStepExpression, which is a SlashExpression in which the lhs operand is known to return a singleton and the rhs operand is known to be an AxisExpression

Constructor Summary

SimpleStepExpressionCompiler()

Method Summary

void	compileToIterator(CompilerService compiler, Expression expression) Generate bytecode to evaluate the expression as a SequenceIterator Precondition: none.
void	compileToLoop(CompilerService compiler, Expression expression, LoopBodyGenerator loopBody) The compileToLoop method compiles this expression in such a way that the code generated by the supplied loopBody argument will be executed once for each item in the result of this expression.

Methods inherited from class com.saxonica.bytecode.ToIteratorCompiler

compileToBoolean, compileToItem, compileToPush

Methods inherited from class com.saxonica.bytecode.ExpressionCompiler

allocateStatic, compileItemFromInt, compileItemFromString, 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

SimpleStepExpressionCompiler

public SimpleStepExpressionCompiler()

Method Detail

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

compileToLoop

public void compileToLoop(CompilerService compiler,
                          Expression expression,
                          LoopBodyGenerator loopBody)
                   throws CannotCompileException

The compileToLoop method compiles this expression in such a way that the code generated by the supplied loopBody argument will be executed once for each item in the result of this expression. The code generated by the loopBody expects to find this item on the top of the bytecode stack.

Overrides:

compileToLoop in class ExpressionCompiler

Parameters:

compiler - the compiler service

expression - the expression to be compiled

loopBody - a generator which produces code to be executed once for every item in the result of this expression, with that item being on the top of the bytecode stack.

Throws:

CannotCompileException