com.saxonica.codegen
Class LetExpressionCompiler

java.lang.Object
  extended by com.saxonica.codegen.ExpressionCompiler
      extended by com.saxonica.codegen.SequenceExpressionCompiler
          extended by com.saxonica.codegen.LetExpressionCompiler

public class LetExpressionCompiler
extends SequenceExpressionCompiler

Compiles Java code to implement a Let expression


Constructor Summary
LetExpressionCompiler()
           
 
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)
          Compile code to push the results of the expression 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)
          Compile code to produce the effective boolean value of the expression
 String compileToItem(CompilerService compiler, Expression expr)
          Compile code to return the results of the expression as an Item.
 String compileToIterator(CompilerService compiler, Expression expr)
          Compile code to produce a SequenceIterator over the results of the expression
 String compileToValueRepresentation(CompilerService compiler, Expression expr)
          Generate Java code to evaluate the expression as a ValueRepresentation
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Constructor Detail

LetExpressionCompiler

public LetExpressionCompiler()
Method Detail

compileToIterator

public String compileToIterator(CompilerService compiler,
                                Expression expr)
Compile code to produce a SequenceIterator over the results of the expression

Specified by:
compileToIterator in class ExpressionCompiler
Parameters:
compiler - The CompilerService
expr - the LetExpression to be compiled
Returns:
the compiled Java expression

compileToValueRepresentation

public String compileToValueRepresentation(CompilerService compiler,
                                           Expression expr)
Description copied from class: ExpressionCompiler
Generate Java code to evaluate the expression as a ValueRepresentation

Overrides:
compileToValueRepresentation in class ExpressionCompiler
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 ValueRepresentation, and which at run-time will hold the value of the expression

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

compilePush

public void compilePush(CompilerService compiler,
                        Expression expr)
Compile code to push the results of the expression to the current output receiver

Overrides:
compilePush in class SequenceExpressionCompiler
Parameters:
compiler - The CompilerService
expr - the LetExpression to be compiled

compileToItem

public String compileToItem(CompilerService compiler,
                            Expression expr)
Compile code to return the results of the expression as an Item. For use only when the cardinality is known to be zero-or-one

Overrides:
compileToItem in class SequenceExpressionCompiler
Parameters:
compiler - The CompilerService
expr - the LetExpression to be compiled
Returns:
the compiled Java expression

compileToEffectiveBooleanValue

public String compileToEffectiveBooleanValue(CompilerService compiler,
                                             Expression expr,
                                             ReturnAction options)
Compile code to produce the effective boolean value of the expression

Overrides:
compileToEffectiveBooleanValue in class SequenceExpressionCompiler
Parameters:
compiler - The CompilerService
expr - the LetExpression to be compiled
options -
Returns:
the compiled Java expression

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


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