com.saxonica.bytecode
Class ChooseCompiler

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

public class ChooseCompiler
extends ToIteratorCompiler

Generate code for a conditional expression (if-then-else, xsl:if, xsl:choose, typeswitch...)

Constructor Summary

ChooseCompiler()

Method Summary

void	compileToBoolean(CompilerService compiler, Expression expression) Generate bytecode to evaluate the expression as a boolean Precondition: none.
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	compileToPrimitive(CompilerService compiler, Expression expression, Class requiredClass, OnEmpty onEmpty) Generate bytecode to evaluate the expression leaving a plain Java value on the stack.
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, compileToLoop, 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

ChooseCompiler

public ChooseCompiler()

Method Detail

compileToIterator

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

Generate bytecode to evaluate the expression as a SequenceIterator Precondition: none. Postcondition: 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

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).

Overrides:

compileToItem in class ToIteratorCompiler

Parameters:

compiler - the compiler service

expression - the expression to be compiled

Throws:

CannotCompileException

compileToBoolean

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

Description copied from class: ExpressionCompiler

Generate bytecode to evaluate the expression as a boolean Precondition: none. Postcondition: at execution time, the stack contains an integer (0=false, 1=true) representing the result of the expression

Overrides:

compileToBoolean in class ToIteratorCompiler

Parameters:

compiler - the compiler service

expression - the expression to be compiled

Throws:

CannotCompileException

compileToPrimitive

public void compileToPrimitive(CompilerService compiler,
                               Expression expression,
                               Class requiredClass,
                               OnEmpty onEmpty)
                        throws CannotCompileException

Description copied from class: ExpressionCompiler

Generate bytecode to evaluate the expression leaving a plain Java value on the stack. This method must only be called if the static type of the expressionis such that the value is known to be representable by a value of the specified class; the cardinality must be either exactly-one or zero-or-one.

Overrides:

compileToPrimitive in class ExpressionCompiler

Parameters:

compiler - the compiler service

expression - the expression to be compiled

requiredClass - the class of the Java value that is to be left on the stack if the generated code exits normally. This must be one of Integer.TYPE, Double.TYPE, Float.TYPE, BigDecimal.class, CharSequence.class.

onEmpty - defines the action to be taken if the expression evaluates to the empty sequence. May be null if the expression is known statically not to evaluate to an empty sequence. If the return class is a primitive type (double, float, etc) this must be an instance of OnEmpty.UnwindAndJump

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

Overrides:

compileToPush in class ToIteratorCompiler

Parameters:

compiler - the compiler service

expression - the expression to be compiled

Throws:

CannotCompileException