com.saxonica.codegen
Class PushExpressionCompiler

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

Direct Known Subclasses:

BlockCompiler, CommentCompiler, ComputedAttributeCompiler, ComputedElementCompiler, CopyOfCompiler, FixedAttributeCompiler, FixedElementCompiler, ProcessingInstructionCompiler, ValueOfCompiler

public abstract class PushExpressionCompiler
extends ExpressionCompiler

Superclass for compiling expressions whose natural evaluation mode is "push", that is, expressions that construct new nodes.

Constructor Summary

PushExpressionCompiler()

Method Summary

String	compileToCharSequence(CompilerService compiler, Expression exp) Generate Java code to evaluate the expression as a CharSequence
String	compileToEffectiveBooleanValue(CompilerService compiler, Expression expr, ReturnAction result) 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
String	getStaticBaseURI(Expression exp) Get the base URI of the instruction being compiled.
static String	prepareToPush(int n, CompilerService compiler, Expression exp, String baseURI)

Methods inherited from class com.saxonica.codegen.ExpressionCompiler

compileAsLoop, compilePush, compileToValueRepresentation

Methods inherited from class java.lang.Object

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

Constructor Detail

PushExpressionCompiler

public PushExpressionCompiler()

Method Detail

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

prepareToPush

public static String prepareToPush(int n,
                                   CompilerService compiler,
                                   Expression exp,
                                   String baseURI)

compileToEffectiveBooleanValue

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

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

expr - the XPath expression to be compiled

result - 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

getStaticBaseURI

public String getStaticBaseURI(Expression exp)

Get the base URI of the instruction being compiled. The default implementation returns null, indicating that the base URI is not needed for this kind of instruction