com.saxonica.bytecode
Class ContainsCompiler

java.lang.Object
  com.saxonica.bytecode.ExpressionCompiler
      com.saxonica.bytecode.ToBooleanCompiler
          com.saxonica.bytecode.ContainsCompiler

public class ContainsCompiler
extends ToBooleanCompiler

Generate bytecode for a call on fn:contains

Constructor Summary

ContainsCompiler()

Method Summary

void	compileToBoolean(CompilerService compiler, Expression expression) Generate bytecode to evaluate the expression as a boolean Precondition: none.
protected static void	returnIfEmpty(CompilerService compiler, Expression arg, LabelInfo returnLabel, int popsNeeded) Utility method for use by subclasses to generate code that causes an boolean result to be returned if the first argument is an empty sequence or zero-length string.
static void	useDynamicCollation(CompilerService compiler, CollatingFunction function, StringCollator stringCollator) Common code for handling non-standard collations in starts-with and similar functions.

Methods inherited from class com.saxonica.bytecode.ToBooleanCompiler

compileToItem, compileToIterator, compileToPush

Methods inherited from class com.saxonica.bytecode.ExpressionCompiler

allocateStatic, compileItemFromInt, compileItemFromString, compileToLoop, compileToPrimitive, generateMethod, getConfiguration, handleEmptyStringResult, setConfiguration, throwXPathException, throwXPathException, unboxItem, verify, visitAnnotation, visitLineNumber

Methods inherited from class java.lang.Object

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

Constructor Detail

ContainsCompiler

public ContainsCompiler()

Method Detail

compileToBoolean

public void compileToBoolean(CompilerService compiler,
                             Expression expression)
                      throws CannotCompileException

Description copied from class: ExpressionCompiler

Generate bytecode to evaluate the expression as a boolean Precondition: none. Postcondition: at execution time, the stack contains an integer (0=false, 1=true) representing the result of the expression

Specified by:

compileToBoolean in class ExpressionCompiler

Parameters:

compiler - the compiler service

expression - the expression to be compiled

Throws:

CannotCompileException

returnIfEmpty

protected static void returnIfEmpty(CompilerService compiler,
                                    Expression arg,
                                    LabelInfo returnLabel,
                                    int popsNeeded)

Utility method for use by subclasses to generate code that causes an boolean result to be returned if the first argument is an empty sequence or zero-length string. Precondition: the value of the first argument is on the stack, as a CharSequence Postcondition: either the control has jumped to the return label with the given result on the stack, or control drops through with the value of the first argument still on the stack (as supplied).

Parameters:

compiler - the compiler

arg - the first argument

returnLabel - the label to jump to if the argument is an empty sequence or zero-length string

popsNeeded - the number of items to pop from the stack if jumping to the return label

useDynamicCollation

public static void useDynamicCollation(CompilerService compiler,
                                       CollatingFunction function,
                                       StringCollator stringCollator)
                                throws CannotCompileException

Common code for handling non-standard collations in starts-with and similar functions. This is used both when the collation is explicitly specified and when it is dynamically computed. On exit a StringCollator will have been added to the stack.

Parameters:

compiler -

function -

stringCollator -

Throws:

CannotCompileException