Package com.saxonica.ee.bytecode

Class SubstringCompiler

java.lang.Object

com.saxonica.ee.bytecode.ExpressionCompiler

com.saxonica.ee.bytecode.ToItemCompiler

com.saxonica.ee.bytecode.SubstringCompiler

public class SubstringCompiler
extends ToItemCompiler

Generate bytecode for evaluation of a call to the substring() function

Constructor Summary

Constructors

Constructor	Description
SubstringCompiler()

Method Summary

Modifier and Type	Method	Description
void	compileToItem(CompilerService compiler, Expression expression)	Generate bytecode to evaluate the expression as an Item Precondition: none.
void	compileToPrimitive(CompilerService compiler, Expression expression, java.lang.Class requiredClass, OnEmpty onEmpty)	Generate bytecode to evaluate the expression leaving a plain Java value on the stack.

Methods inherited from class com.saxonica.ee.bytecode.ToItemCompiler

compileToBoolean, compileToIterator, compileToPush, returnZeroLengthStringIfNull

Methods inherited from class com.saxonica.ee.bytecode.ExpressionCompiler

allocateStatic, compileItemFromInt, generateMethod, handleEmptyStringResult, printStackTop, verify, visitAnnotation, visitLineNumber

Methods inherited from class java.lang.Object

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

Constructor Detail

SubstringCompiler

public SubstringCompiler()

Method Detail

compileToPrimitive

public void compileToPrimitive(CompilerService compiler,
                               Expression expression,
                               java.lang.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 - if the expression cannot be compiled to bytecode

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 - if the expression cannot be compiled to bytecode