Package org.basex.query.func

Class FuncLit

java.lang.Object

org.basex.query.expr.ExprInfo

org.basex.query.expr.Expr

org.basex.query.expr.ParseExpr

org.basex.query.expr.Single

org.basex.query.func.FuncLit

All Implemented Interfaces:

XQFunctionExpr, Scope

public final class FuncLit
extends Single
implements Scope, XQFunctionExpr

A named function literal.

Author:

BaseX Team 2005-24, BSD License, Leo Woerteler

Field Summary

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

expr

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

exprType, info

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.
AnnList	annotations()	Annotations of this function.
int	arity()	Number of arguments this function takes.
Expr	compile(CompileContext cc)	Compiles and optimizes the expression, assigns types and cardinalities.
boolean	compiled()	Checks if this scope has already been compiled.
Expr	copy(CompileContext cc, IntObjMap<Var> vm)	Copies an expression.
String	description()	Returns a string description of the expression.
boolean	equals(Object obj)	This function is e.g. called by: If.optimize(CompileContext), Switch.optimize(CompileContext), Typeswitch.optimize(CompileContext), in order to discard identical expressions.
QNm	funcName()	Name of this function, null means anonymous function.
Expr	inline(Expr[] exprs, CompileContext cc)	Tries to inline this function with the given arguments.
FuncItem	item(QueryContext qc, InputInfo ii)	Evaluates the expression and returns the resulting item, or Empty.VALUE if the expression yields an empty sequence.
Expr	optimize(CompileContext cc)	Optimizes an already compiled expression without recompiling its sub-expressions.
QNm	paramName(int pos)	Name of the parameter at the given position.
void	toString(QueryString qs)	Creates a query string.
boolean	vacuousBody()	Checks if this function returns vacuous results (see Expr.vacuous()).
boolean	visit(ASTVisitor visitor)	Traverses this scope with the given ASTVisitor.

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

arg, args, checkUp, count, exprSize, has, inline, inlineable, toXml

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

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

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

atomItem, atomIter, ddo, funcType, hasFreeVars, indexAccessible, info, isSimple, markTailCalls, mergeEbv, optimizePos, simplify, simplifyFor, typeCheck, uses, vacuous, 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

Methods inherited from interface org.basex.query.scope.Scope

reset

Methods inherited from interface org.basex.query.func.XQFunctionExpr

funcType

Method Detail

arity

public int arity()

Description copied from interface: XQFunctionExpr

Number of arguments this function takes.

Specified by:

arity in interface XQFunctionExpr

Returns:

function arity

funcName

public QNm funcName()

Description copied from interface: XQFunctionExpr

Name of this function, null means anonymous function.

Specified by:

funcName in interface XQFunctionExpr

Returns:

name or null

paramName

public QNm paramName(int pos)

Description copied from interface: XQFunctionExpr

Name of the parameter at the given position.

Specified by:

paramName in interface XQFunctionExpr

Parameters:

pos - position of the parameter

Returns:

name of the parameter

annotations

public AnnList annotations()

Description copied from interface: XQFunctionExpr

Annotations of this function.

Specified by:

annotations in interface XQFunctionExpr

Returns:

this function's annotations

inline

public Expr inline(Expr[] exprs,
                   CompileContext cc)
            throws QueryException

Description copied from interface: XQFunctionExpr

Tries to inline this function with the given arguments.

Specified by:

inline in interface XQFunctionExpr

Parameters:

exprs - arguments

cc - compilation context

Returns:

the expression to inline if successful, null otherwise

Throws:

QueryException - query exception

vacuousBody

public boolean vacuousBody()

Description copied from interface: XQFunctionExpr

Checks if this function returns vacuous results (see Expr.vacuous()).

Specified by:

vacuousBody in interface XQFunctionExpr

Returns:

result of check

compile

public Expr compile(CompileContext cc)
             throws QueryException

Description copied from class: Expr

Compiles and optimizes the expression, assigns types and cardinalities.

Specified by:

compile in interface Scope

Overrides:

compile in class Single

Parameters:

cc - compilation context

Returns:

optimized expression

Throws:

QueryException - query exception

optimize

public Expr optimize(CompileContext cc)
              throws QueryException

Description copied from class: Expr

Optimizes an already compiled expression without recompiling its sub-expressions.

Overrides:

optimize in class Single

Parameters:

cc - compilation context

Returns:

optimized expression

Throws:

QueryException - query exception

compiled

public boolean compiled()

Description copied from interface: Scope

Checks if this scope has already been compiled.

Specified by:

compiled in interface Scope

Returns:

result of check

item

public FuncItem item(QueryContext qc,
                     InputInfo ii)

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 (can be null); required for those Value instances that have no input info)

Returns:

item or Empty.VALUE

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 by VarRef.inline(org.basex.query.InlineContext), FuncItem.inline(org.basex.query.expr.Expr[], org.basex.query.CompileContext), Closure.inline(org.basex.query.InlineContext) and StaticFunc.inline(org.basex.query.expr.Expr[], org.basex.query.CompileContext).

Specified by:

copy in class Expr

Parameters:

cc - compilation context

vm - mapping from old variable IDs to new variable copies. Required by Closure.copy(org.basex.query.CompileContext, org.basex.util.hash.IntObjMap<org.basex.query.var.Var>) and VarRef.copy(org.basex.query.CompileContext, org.basex.util.hash.IntObjMap<org.basex.query.var.Var>)

Returns:

copied expression

visit

public boolean visit(ASTVisitor visitor)

Description copied from interface: Scope

Traverses this scope with the given ASTVisitor.

Specified by:

visit in interface Scope

Parameters:

visitor - visitor

Returns:

continue flag

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 Single

Parameters:

visitor - visitor

Returns:

if the walk should be continued

equals

public boolean equals(Object obj)

Description copied from class: Single

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) or CmpSR.mergeEbv(Expr, boolean, CompileContext), in order to merge expressions with identical input.
• CmpG.optimize(CompileContext) or CmpV.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.

Must be overwritten by implementing class.

Overrides:

equals in class Single

description

public String description()

Description copied from class: ExprInfo

Returns a string description of the expression. This method is only called by error messages. Contrary to the ExprInfo.toString() method, arguments are not included in the output.

Overrides:

description in class ExprInfo

Returns:

result of check

toString

public void toString(QueryString qs)

Description copied from class: ExprInfo

Creates a query string.

Specified by:

toString in class ExprInfo

Parameters:

qs - query string builder