Package org.basex.query.func.fn

Class FnDistinctValues

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.FnDistinctValues

public final class FnDistinctValues
extends StandardFunc

Function implementation.

Author:

BaseX Team 2005-21, 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
FnDistinctValues()

Method Summary

Modifier and Type	Method	Description
Expr	duplicates(CmpV.OpV op, CompileContext cc)	Rewrites the function call to a duplicate check.
Iter	iter(QueryContext qc)	Evaluates the expression and returns an iterator on the resulting items.
protected Expr	opt(CompileContext cc)	Performs function specific optimizations.
protected void	simplifyArgs(CompileContext cc)	Simplifies the types of all arguments.
Value	value(QueryContext qc)	Evaluates the expression and returns the resulting value.

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

checkAdmin, checkArity, checkArity, checkCreate, checkData, checkPath, checkPath, coerceFunc, compileData, copy, data, data, dataLock, dateTimeToMs, description, equals, has, optFirst, optFirst, optimize, plan, plan, serialize, toBaseUri, toBindings, toCollation, toDate, toDBNode, toEncodingOrNull, toNodeOrAtomItem, toOptions, toPath, toPath, toQuery, toQuery, vacuous

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

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

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

adoptType, atomValue, checkAllUp, checkNoEmpty, checkNoEmpty, checkNoneUp, checkNoUp, checkType, checkType, checkUp, copyType, ctxValue, ebv, item, refineType, seqType, size, test, toArray, toArray, toAtomItem, toB64, toB64, toBin, toBin, toBoolean, toBoolean, toBytes, toBytes, toDouble, toDouble, toElem, toFloat, toFunc, toItem, toItem, toLong, toLong, toMap, toMap, toNode, toNode, toNodeOrNull, toNumber, toNumberOrNull, toQNm, toQNm, toToken, toToken, toTokenOrNull, toZeroToken

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

arg, atomItem, atomIter, ddo, funcType, hasFreeVars, indexAccessible, isSimple, markTailCalls, mergeEbv, simplifyFor, 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 Details

FnDistinctValues

public FnDistinctValues()

Method Details

iter

public Iter iter(QueryContext qc)
          throws QueryException

Description copied from class: Expr

Evaluates the expression and returns an iterator on the resulting items. The implementation of this method is optional.

Overrides:

iter in class ParseExpr

Parameters:

qc - query context

Returns:

iterator

Throws:

QueryException - query exception

value

public Value value(QueryContext qc)
            throws QueryException

Description copied from class: Expr

Evaluates the expression and returns the resulting value. If this method is not implemented, Expr.item(QueryContext, InputInfo) must be implemented instead.

Overrides:

value in class ParseExpr

Parameters:

qc - query context

Returns:

value

Throws:

QueryException - query exception

simplifyArgs

protected void simplifyArgs(CompileContext cc)
                     throws QueryException

Description copied from class: StandardFunc

Simplifies the types of all arguments. This function is overwritten by functions that rely on the original argument type.

Overrides:

simplifyArgs in class StandardFunc

Parameters:

cc - compilation context

Throws:

QueryException - query exception

opt

protected Expr opt(CompileContext cc)
            throws QueryException

Description copied from class: StandardFunc

Performs function specific optimizations.

Overrides:

opt in class StandardFunc

Parameters:

cc - compilation context

Returns:

optimized or original expression

Throws:

QueryException - query exception

duplicates

public Expr duplicates(CmpV.OpV op,
 CompileContext cc)
                throws QueryException

Rewrites the function call to a duplicate check.

Parameters:

op - comparison operator

cc - compilation context

Returns:

new function or null

Throws:

QueryException - query context