org.basex.query.flwor

Class ForLet

java.lang.Object

org.basex.data.ExprInfo

org.basex.query.expr.Expr

org.basex.query.expr.ParseExpr

org.basex.query.expr.Single

org.basex.query.flwor.ForLet

Direct Known Subclasses:

For, Let

public abstract class ForLet
extends Single

Abstract For/Let Clause.

Author:

BaseX Team 2005-12, BSD License, Christian Gruen

Nested Class Summary

Nested classes/interfaces inherited from class org.basex.query.expr.Expr

Expr.Use

Field Summary

Fields

Modifier and Type	Field and Description
Var	var Variable.

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

expr

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

input, size, type

Method Summary

Methods

Modifier and Type	Method and Description
abstract ForLet	comp(QueryContext ctx) Compiles and optimizes the expression, assigns data types and cardinalities.
abstract boolean	declares(Var v) Checks if the given variable is declared by this clause.
boolean	uses(Expr.Use u) Indicates if an expression uses the specified type or operation.
abstract Var[]	vars() Gathers all variables declared by this clause.

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

count, plan, removable, remove

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

checkBln, checkColl, checkCreate, checkCtx, checkDbl, checkDBNode, checkEStr, checkEStr, checkIO, checkItem, checkItr, checkItr, checkMap, checkNode, checkNoEmpty, checkStr, checkType, checkUp, checkUp, checkWrite, compBln, ebv, item, iter, optPre, preEval, size, test, type, value

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

addText, compEbv, hasFreeVars, indexAccessible, indexEquivalent, isEmpty, isFunction, isItem, isVacuous, isValue, iterable, markTailCalls, sameAs

Methods inherited from class org.basex.data.ExprInfo

description, info, toString

Methods inherited from class java.lang.Object

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

Field Detail

var

public final Var var

Variable.

Method Detail

comp

public abstract ForLet comp(QueryContext ctx)
                     throws QueryException

Description copied from class: Expr

Compiles and optimizes the expression, assigns data types and cardinalities.

Overrides:

comp in class Single

Parameters:

ctx - query context

Returns:

optimized expression

Throws:

QueryException - query exception

uses

public final boolean uses(Expr.Use u)

Description copied from class: Expr

Indicates if an expression uses the specified type or operation. This method is called by numerous Expr.comp(org.basex.query.QueryContext) methods to test the properties of sub-expressions. It will return true as soon as at least one test is successful.

Overrides:

uses in class Single

Parameters:

u - type/operation to be found

Returns:

result of check

declares

public abstract boolean declares(Var v)

Checks if the given variable is declared by this clause.

Parameters:

v - variable

Returns:

declaration flag

vars

public abstract Var[] vars()

Gathers all variables declared by this clause.

Returns:

variables