com.saxonica.codegen
Class SequenceExpressionCompiler

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

Direct Known Subclasses:

AtomicMappingCompiler, AtomicSequenceConverterCompiler, AtomizerCompiler, AxisExpressionCompiler, CardinalityCheckerCompiler, CollectionCompiler, ConditionalSorterCompiler, DistinctValuesCompiler, DocumentSorterCompiler, ExtensionFunctionCallCompiler, FilterExpressionCompiler, ForExpressionCompiler, IdCompiler, IdrefCompiler, IndexedFilterExpressionCompiler, IndexOfCompiler, InScopePrefixesCompiler, InsertCompiler, ItemCheckerCompiler, KeyFnCompiler, LazyExpressionCompiler, LetExpressionCompiler, LocalVariableReferenceCompiler, NumericPromoterCompiler, PathExpressionCompiler, RangeExpressionCompiler, RemoveCompiler, ReverseCompiler, SlashExpressionCompiler, StringToCodepointsCompiler, SubsequenceCompiler, TailCallLoopCompiler, TailExpressionCompiler, TokenizeCompiler, TupleSorterCompiler, UntypedAtomicConverterCompiler, UserFunctionCallCompiler, VariableReferenceCompiler, VennExpressionCompiler

public abstract class SequenceExpressionCompiler
extends ExpressionCompiler

Superclass for compiling expressions whose natural evaluation mode is "pull", for example, expressions that read and return existing nodes.

Constructor Summary

SequenceExpressionCompiler()

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	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

Methods inherited from class com.saxonica.codegen.ExpressionCompiler

compileAsLoop, compileToCharSequence, compileToIterator, compileToValueRepresentation

Methods inherited from class java.lang.Object

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

Constructor Detail

SequenceExpressionCompiler

public SequenceExpressionCompiler()

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).

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).

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