# FtIndexLookup
Keywords: org.exist.xquery.functions.system.FtIndexLookup class

## org.exist.xquery.functions.system
Class FtIndexLookup

    java.lang.Object
      org.exist.xquery.AbstractExpression
          org.exist.xquery.PathExpr
              org.exist.xquery.Function
                  org.exist.xquery.functions.system.FtIndexLookup

All Implemented Interfaces:
  CompiledExpression, CompiledXQuery, Expression

public class FtIndexLookup
extends Function

Field Summary
`static FunctionSignature` `signature`

Fields inherited from class org.exist.xquery.Function
`BUILTIN_FUNCTION_NS`

Fields inherited from interface org.exist.xquery.Expression
`DOT_TEST, EXPRESSION_ID_INVALID, IGNORE_CONTEXT, IN_PREDICATE, IN_UPDATE, IN_WHERE_CLAUSE, NO_CONTEXT_ID, SINGLE_STEP_EXECUTION`

Constructor Summary
`FtIndexLookup(XQueryContext context)`

Method Summary
`void` `analyze(AnalyzeContextInfo contextInfo)` Statically analyze the expression and its subexpressions.
`Sequence` `eval(Sequence contextSequence, Item contextItem)` Evaluate the expression represented by this object.
`int` `getDependencies()` Overwritten: function can process the whole context sequence at once.
`void` `setArguments(java.util.List arguments)` Overwritten to disable automatic type checks.

Methods inherited from class org.exist.xquery.Function
`createFunction, dump, getArgument, getArgumentCount, getArguments, getASTNode, getCardinality, getName, getParent, getSignature, isCalledAs, returnsType, setASTNode, setParent, setPrimaryAxis, toString`

Methods inherited from class org.exist.xquery.PathExpr
`accept, add, add, addPath, addPredicate, dump, getContext, getDocumentSet, getExpression, getLastExpression, getLength, getLiteralValue, getSource, isValid, replaceLastExpression, reset, resetState, setContext, setSource`

Methods inherited from class org.exist.xquery.AbstractExpression
`eval, getContextDocSet, getContextId, getExpressionId, setContextDocSet`

Methods inherited from class java.lang.Object
`equals, getClass, hashCode, notify, notifyAll, wait, wait, wait`

Methods inherited from interface org.exist.xquery.CompiledXQuery
`eval`

Field Detail

### signature

    public static final FunctionSignature signature

Constructor Detail

### FtIndexLookup

    public FtIndexLookup(XQueryContext context)

Method Detail

### getDependencies

    public int getDependencies()

  Overwritten: function can process the whole context sequence at once.

  Specified by:
    `getDependencies` in interface `Expression`
  Overrides:
    `getDependencies` in class `Function`
  See Also:
    `Expression.getDependencies()`

### setArguments

    public void setArguments(java.util.List arguments)
                      throws XPathException

  Overwritten to disable automatic type checks. We check manually.

  Overrides:
    `setArguments` in class `Function`
  Parameters:
    `arguments` -
  Throws:
    `XPathException`
  See Also:
    `Function.setArguments(java.util.List)`

### analyze

    public void analyze(AnalyzeContextInfo contextInfo)
                 throws XPathException

  Description copied from interface: `Expression`
  Statically analyze the expression and its subexpressions. During the static analysis phase, the query engine can detect unknown variables and some type errors.

  Specified by:
    `analyze` in interface `Expression`
  Overrides:
    `analyze` in class `Function`
  Throws:
    `XPathException`

### eval

    public Sequence eval(Sequence contextSequence,
                         Item contextItem)
                  throws XPathException

  Description copied from interface: `Expression`
  Evaluate the expression represented by this object. Depending on the context in which this expression is executed, either the context sequence, the context item or both of them may be set. An implementing class should know how to handle this. The general contract is as follows: if the `Dependency.CONTEXT_ITEM` bit is set in the bit field returned by `Expression.getDependencies()`, the eval method will be called once for every item in the context sequence. The contextItem parameter will be set to the current item. Otherwise, the eval method will only be called once for the whole context sequence and contextItem will be null. eXist tries to process the entire context set in one, single step whenever possible. Thus, most classes only expect context to contain a list of nodes which represents the current context of the expression. The position() function in XPath is an example for an expression, which requires both, context sequence and context item to be set. The context sequence might be a node set, a sequence of atomic values or a single node or atomic value.

  Specified by:
    `eval` in interface `Expression`
  Specified by:
    `eval` in class `Function`
  Throws:
    `XPathException`

Copyright (C) Wolfgang Meier. All rights reserved.