com.saxonica.codegen
Class ErrorExpressionCompiler

java.lang.Object
  com.saxonica.codegen.ExpressionCompiler
      com.saxonica.codegen.ErrorExpressionCompiler

public class ErrorExpressionCompiler
extends ExpressionCompiler

Generate Java code to implement an ErrorExpression: this is an expression generated by the parser when it is known statically that execution of an expression will necessarily fail, but where the error is not generated at compile time because the expression might not be evalauated.

Constructor Summary

ErrorExpressionCompiler()

Method Summary

void	compilePush(CompilerService compiler, Expression exp) 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 exp) Generate Java code to evaluate the expression as a CharSequence
String	compileToEffectiveBooleanValue(CompilerService compiler, Expression exp, ReturnAction options) Generate Java code to evaluate the effective boolean value of the expression
String	compileToItem(CompilerService compiler, Expression exp) Generate Java code to evaluate the expression as an Item
String	compileToIterator(CompilerService compiler, Expression exp) Generate Java code to evaluate the expression as a SequenceIterator

Methods inherited from class com.saxonica.codegen.ExpressionCompiler

compileAsLoop, compileToValueRepresentation

Methods inherited from class java.lang.Object

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

Constructor Detail

ErrorExpressionCompiler

public ErrorExpressionCompiler()

Method Detail

compilePush

public void compilePush(CompilerService compiler,
                        Expression exp)

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

Specified by:

compilePush in class ExpressionCompiler

Parameters:

compiler - the compiler service

exp - the expression to be compiled

compileToItem

public String compileToItem(CompilerService compiler,
                            Expression exp)

Description copied from class: ExpressionCompiler

Generate Java code to evaluate the expression as an Item

Specified by:

compileToItem in class ExpressionCompiler

Parameters:

compiler - the compiler service

exp - 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).

compileToIterator

public String compileToIterator(CompilerService compiler,
                                Expression exp)

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

exp - 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

compileToEffectiveBooleanValue

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

Description copied from class: ExpressionCompiler

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

Specified by:

compileToEffectiveBooleanValue in class ExpressionCompiler

Parameters:

compiler - the compiler service

exp - 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 exp)

Description copied from class: ExpressionCompiler

Generate Java code to evaluate the expression as a CharSequence

Specified by:

compileToCharSequence in class ExpressionCompiler

Parameters:

compiler - the compiler service

exp - 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