Package org.basex.query.expr
Class ContextValue
- java.lang.Object
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- org.basex.query.expr.ExprInfo
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- org.basex.query.expr.Expr
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- org.basex.query.expr.ParseExpr
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- org.basex.query.expr.Simple
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- org.basex.query.expr.ContextValue
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public final class ContextValue extends Simple
Context value.- Author:
- BaseX Team 2005-22, BSD License, Christian Gruen
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Constructor Summary
Constructors Constructor Description ContextValue(InputInfo info)
Constructor.
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Method Summary
All Methods Static Methods Instance Methods Concrete Methods 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.Expr
copy(CompileContext cc, IntObjMap<Var> vm)
Copies an expression.VarUsage
count(Var var)
Checks how often a variable or context reference is used in this expression.boolean
equals(Object obj)
This function is e.g.static Expr
get(CompileContext cc, InputInfo ii)
Creates a new, optimized context value expression.boolean
has(Flag... flags)
Indicates if an expression has one of the specified compiler properties.Expr
inline(InlineContext ic)
Inlines an expression into this one, replacing all variable or context references.Expr
optimize(CompileContext cc)
Optimizes an already compiled expression without recompiling its sub-expressions.void
toString(QueryString qs)
Creates a query string.Value
value(QueryContext qc)
Evaluates the expression and returns the resulting value.-
Methods inherited from class org.basex.query.expr.Simple
checkUp, compile, exprSize, inlineable, toXml
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Methods inherited from class org.basex.query.expr.ParseExpr
adoptType, atomValue, checkAllUp, checkNoEmpty, checkNoEmpty, checkNoneUp, checkNoUp, checkType, checkType, checkUp, copyType, ctxValue, data, ebv, info, item, iter, refineType, seqType, size, test, toArray, toArray, toAtomItem, toB64, toB64, toBin, toBin, toBoolean, toBoolean, toBytes, toBytes, toDouble, toDouble, toElem, toFloat, toFunction, toItem, toItem, toLong, toLong, toMap, toMap, toNode, toNode, toNodeOrNull, toNumber, toNumberOrNull, toQNm, toQNm, toString, toString, toStringOrNull, toToken, toToken, toTokenOrNull, toZeroToken
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Methods inherited from class org.basex.query.expr.Expr
arg, args, atomItem, atomIter, ddo, funcType, hasFreeVars, indexAccessible, isSimple, markTailCalls, mergeEbv, optimizePos, simplify, simplifyFor, typeCheck, uses, vacuous, visitAll
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Methods inherited from class org.basex.query.expr.ExprInfo
description, toErrorString, toString
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Constructor Detail
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ContextValue
public ContextValue(InputInfo info)
Constructor.- Parameters:
info
- input info
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Method Detail
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get
public static Expr get(CompileContext cc, InputInfo ii)
Creates a new, optimized context value expression.- Parameters:
cc
- compilation contextii
- input info- Returns:
- optimized expression
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optimize
public Expr optimize(CompileContext cc)
Description copied from class:Expr
Optimizes an already compiled expression without recompiling its sub-expressions.
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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 classParseExpr
- Parameters:
qc
- query context- Returns:
- value
- Throws:
QueryException
- query exception
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has
public boolean has(Flag... flags)
Description copied from class:Expr
Indicates if an expression has one of the specified compiler properties. This method must only be called at compile time. It is invoked to test properties of sub-expressions. It returnstrue
if at least flag matches an expression.
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count
public VarUsage count(Var var)
Description copied from class:Expr
Checks how often a variable or context reference is used in this expression. This function is called by:-
Closure.optimize(org.basex.query.CompileContext)
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GFLWOR.inlineForLet(org.basex.query.CompileContext)
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GFLWOR.optimizePos(org.basex.query.CompileContext)
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GFLWOR.simplify(org.basex.query.CompileContext)
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GFLWOR.unusedVars(org.basex.query.CompileContext)
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SimpleMap.optimize(org.basex.query.CompileContext)
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TypeswitchGroup.optimize(org.basex.query.CompileContext)
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inline
public Expr inline(InlineContext ic) throws QueryException
Description copied from class:Expr
Inlines an expression into this one, replacing all variable or context references. This function is called byInlineContext.inline(Expr)
(see invocations of these functions for further inlinings). The variable reference is replaced in: The context is replaced in:- Specified by:
inline
in classExpr
- Parameters:
ic
- inlining context- Returns:
- resulting expression if something has changed,
null
otherwise - Throws:
QueryException
- query exception
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copy
public Expr copy(CompileContext cc, IntObjMap<Var> vm)
Description copied from class:Expr
Copies an expression. Used for inlining functions, or for copying static queries. It is utilized byVarRef.inline(org.basex.query.InlineContext)
,FuncItem.inline(org.basex.query.expr.Expr[], org.basex.query.CompileContext)
,Closure.inline(org.basex.query.InlineContext)
andStaticFunc.inline(org.basex.query.expr.Expr[], org.basex.query.CompileContext)
.- Specified by:
copy
in classExpr
- Parameters:
cc
- compilation contextvm
- mapping from old variable IDs to new variable copies. Required byClosure.copy(org.basex.query.CompileContext, org.basex.util.hash.IntObjMap<org.basex.query.var.Var>)
andVarRef.copy(org.basex.query.CompileContext, org.basex.util.hash.IntObjMap<org.basex.query.var.Var>)
- Returns:
- copied expression
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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.
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equals
public boolean equals(Object obj)
Description copied from class:Expr
This function is e.g. called by:If.optimize(CompileContext)
,Switch.optimize(CompileContext)
,Typeswitch.optimize(CompileContext)
, in order to discard identical expressions.CmpR.mergeEbv(Expr, boolean, CompileContext)
orCmpSR.mergeEbv(Expr, boolean, CompileContext)
, in order to merge expressions with identical input.CmpG.optimize(CompileContext)
orCmpV.optimize(CompileContext)
, in order to pre-evaluate equality tests.CmpG.optimize(CompileContext)
, in order to compare the start and end value.PathCache
, in order to find identical root values at runtime.
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toString
public void toString(QueryString qs)
Description copied from class:ExprInfo
Creates a query string.
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