com.saxonica.codegen
Class LazyExpressionCompiler

java.lang.Object
  com.saxonica.codegen.ExpressionCompiler
      com.saxonica.codegen.SequenceExpressionCompiler
          com.saxonica.codegen.LazyExpressionCompiler

public class LazyExpressionCompiler
extends SequenceExpressionCompiler

Compile code for a LazyExpression - an expression which is always evaluated lazily

Constructor Summary

LazyExpressionCompiler()

Method Summary

void	compileAsLoop(CompilerService compiler, Expression expr, LoopAction action) Compile an expression in the form of a loop.
void	compilePush(CompilerService compiler, Expression expr) Generate Java code to execute the expression in push mode, that is, code to write events to the current output Receiver
String	compileToCharSequence(CompilerService compiler, Expression expr) Generate Java code to evaluate the expression as a CharSequence
String	compileToEffectiveBooleanValue(CompilerService compiler, Expression expr, ReturnAction options) Generate Java code to evaluate the effective boolean value of the expression
static String	compileToEvaluableItem(CompilerService compiler, LazyExpression exp)
String	compileToItem(CompilerService compiler, Expression expr) Generate Java code to evaluate the expression as an Item
String	compileToIterator(CompilerService compiler, Expression expr) Generate Java code to evaluate the expression as a SequenceIterator

Methods inherited from class com.saxonica.codegen.ExpressionCompiler

compileToValueRepresentation, getConfiguration, makeExpressionCompiler, setConfiguration

Methods inherited from class java.lang.Object

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

Constructor Detail

LazyExpressionCompiler

public LazyExpressionCompiler()

Method Detail

compileToIterator

public String compileToIterator(CompilerService compiler,
                                Expression expr)

Description copied from class: ExpressionCompiler

Generate Java code to evaluate the expression as a SequenceIterator

Specified by:

compileToIterator in class ExpressionCompiler

Parameters:

compiler - the compiler service

expr - the XPath expression to be compiled

Returns:

a simple Java expression (usually the name of a variable that has been declared) which will be of class SequenceIterator, and which at run-time will hold an iterator over the the value of the XPath expression

compilePush

public void compilePush(CompilerService compiler,
                        Expression expr)

Description copied from class: ExpressionCompiler

Generate Java code to execute the expression in push mode, that is, code to write events to the current output Receiver

Overrides:

compilePush in class SequenceExpressionCompiler

Parameters:

compiler - the compiler service

expr - the expression to be compiled

compileToItem

public String compileToItem(CompilerService compiler,
                            Expression expr)

Description copied from class: ExpressionCompiler

Generate Java code to evaluate the expression as an Item

Overrides:

compileToItem in class SequenceExpressionCompiler

Parameters:

compiler - the compiler service

expr - the expression to be compiled

Returns:

a simple Java expression (usually the name of a variable that has been declared) which will be of class Item, and which will hold the value of the expression at run-time (or hold null, representing an empty sequence).

compileToEffectiveBooleanValue

public String compileToEffectiveBooleanValue(CompilerService compiler,
                                             Expression expr,
                                             ReturnAction options)

Description copied from class: ExpressionCompiler

Generate Java code to evaluate the effective boolean value of the expression

Overrides:

compileToEffectiveBooleanValue in class SequenceExpressionCompiler

Parameters:

compiler - the compiler service

expr - the XPath expression to be compiled

options - indicates how the boolean result is to be returned

Returns:

the result depends on the supplied value of the options argument. If options is a JavaDeclaration, the code must declare a Java variable and return the name of this variable. If options is a JavaAssignment, the code must assign the value to an existing Java variable. If options is a Return, the code must generate a return statement that returns the value of the boolean (in which case the result of this method is null).

compileToCharSequence

public String compileToCharSequence(CompilerService compiler,
                                    Expression expr)

Description copied from class: ExpressionCompiler

Generate Java code to evaluate the expression as a CharSequence

Overrides:

compileToCharSequence in class ExpressionCompiler

Parameters:

compiler - the compiler service

expr - the XPath expression to be compiled

Returns:

a simple Java expression (usually the name of a variable that has been declared, or a string literal) which will be of class CharSequence, and which will hold the string value of the XPath expression at run-time

compileAsLoop

public void compileAsLoop(CompilerService compiler,
                          Expression expr,
                          LoopAction action)

Compile an expression in the form of a loop. Default implementation.

Overrides:

compileAsLoop in class ExpressionCompiler

Parameters:

compiler - the CompilerService

expr - the expression to be compiled

action - the action to be taken to process each item in the sequence returned by the expression

compileToEvaluableItem

public static String compileToEvaluableItem(CompilerService compiler,
                                            LazyExpression exp)