Package org.basex.query.func.fn

Class FnPosition

java.lang.Object

org.basex.query.expr.ExprInfo

org.basex.query.expr.Expr

org.basex.query.expr.ParseExpr

org.basex.query.expr.Arr

org.basex.query.func.StandardFunc

org.basex.query.func.fn.FnPosition

public final class FnPosition
extends StandardFunc

Function implementation.

Author:

BaseX Team 2005-23, BSD License, Christian Gruen

Field Summary

Fields inherited from class org.basex.query.func.StandardFunc

definition, sc

Fields inherited from class org.basex.query.expr.Arr

exprs

Fields inherited from class org.basex.query.expr.ParseExpr

exprType, info

Constructor Summary

Constructors

Constructor	Description
FnPosition()

Method Summary

Modifier and Type	Method	Description
boolean	accept(ASTVisitor visitor)	Traverses this expression, notifying the visitor of declared and used variables, and checking the tree for other recursive properties.
Int	item(QueryContext qc, InputInfo ii)	Evaluates the expression and returns the resulting item, or Empty.VALUE if the expression yields an empty sequence.
Expr	optimizePos(CmpV.OpV op, CompileContext cc)	Optimizes an expression for positional access.
Expr	simplifyFor(CompileContext.Simplify mode, CompileContext cc)	Simplifies the expression.

Methods inherited from class org.basex.query.func.StandardFunc

checkPerm, coerceFunc, compileData, copy, dataLock, defined, description, embed, equals, has, opt, optFirst, optFirst, optimize, serialize, simplifyArgs, toBaseUri, toBindings, toCollation, toCollationOrDefault, toContent, toContent, toData, toDate, toDBNode, toEncodingOrNull, toFunction, toFunction, toIO, toIO, toMs, toName, toNodeOrAtomItem, toOptions, toOptions, toPath, toPath, toStr, toString, toXml, toZeroStr, updating, vacuous

Methods inherited from class org.basex.query.expr.Arr

allAreValues, arg, args, checkUp, compile, copyAll, count, exprSize, flatten, inline, inlineable, mayBePositional, removeEmpty, simplifyAll

Methods inherited from class org.basex.query.expr.ParseExpr

adoptType, atomValue, checkAllUp, checkNoEmpty, checkNoEmpty, checkNoneUp, checkNoUp, checkType, checkType, checkUp, copyType, ctxValue, data, ebv, info, iter, refineType, seqType, size, test, toArray, toArray, toAtomItem, toB64, toB64, toB64OrNull, toBin, toBin, toBoolean, toBoolean, toBooleanOrFalse, toBytes, toBytes, toDouble, toDouble, toElem, toElem, toFloat, toFunction, toItem, toItem, toLong, toLong, toMap, toMap, toNode, toNode, toNodeOrNull, toNumber, toNumberOrNull, toQNm, toQNmOrNull, toString, toString, toStringOrNull, toToken, toToken, toTokenOrNull, toZeroToken, value

Methods inherited from class org.basex.query.expr.Expr

arg, atomItem, atomIter, ddo, funcType, hasFreeVars, indexAccessible, isSimple, markTailCalls, mergeEbv, simplify, typeCheck, uses, visitAll

Methods inherited from class org.basex.query.expr.ExprInfo

toErrorString, toString

Methods inherited from class java.lang.Object

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

Constructor Detail

FnPosition

public FnPosition()

Method Detail

item

public Int item(QueryContext qc,
                InputInfo ii)
         throws QueryException

Description copied from class: Expr

Evaluates the expression and returns the resulting item, or Empty.VALUE if the expression yields an empty sequence. If this method is not implemented, Expr.value(QueryContext) must be implemented instead.

Overrides:

item in class ParseExpr

Parameters:

qc - query context

ii - input info (only required by Seq instances, which have no input info)

Returns:

item or Empty.VALUE

Throws:

QueryException - query exception

accept

public boolean accept(ASTVisitor visitor)

Description copied from class: Expr

Traverses this expression, notifying the visitor of declared and used variables, and checking the tree for other recursive properties.

Overrides:

accept in class Arr

Parameters:

visitor - visitor

Returns:

if the walk should be continued

simplifyFor

public Expr simplifyFor(CompileContext.Simplify mode,
                        CompileContext cc)
                 throws QueryException

Description copied from class: Expr

Simplifies the expression. Overwritten by many expressions; calls Expr.simplify(Simplify, CompileContext) otherwise.

Overrides:

simplifyFor in class Expr

Parameters:

mode - mode of simplification

cc - compilation context

Returns:

simplified or original expression

Throws:

QueryException - query exception

See Also:

CompileContext.Simplify

optimizePos

public Expr optimizePos(CmpV.OpV op,
                        CompileContext cc)

Description copied from class: Expr

Optimizes an expression for positional access. Overwritten by Int, Range, RangeSeq}.

Overrides:

optimizePos in class Expr

Parameters:

op - comparison operator

cc - compilation context

Returns:

boolean result, optimized or original expression