org.basex.query.func
Class PartFunc

java.lang.Object
  extended by org.basex.data.ExprInfo
      extended by org.basex.query.expr.Expr
          extended by org.basex.query.expr.ParseExpr
              extended by org.basex.query.expr.Arr
                  extended by org.basex.query.func.PartFunc

public final class PartFunc
extends Arr

Partial function application.

Author:
BaseX Team 2005-12, BSD License, Leo Woerteler

Nested Class Summary
 
Nested classes/interfaces inherited from class org.basex.query.expr.Expr
Expr.Flag
 
Field Summary
 
Fields inherited from class org.basex.query.expr.Arr
expr
 
Fields inherited from class org.basex.query.expr.ParseExpr
info, size, type
 
Constructor Summary
PartFunc(InputInfo ii, Expr fn, Expr[] arg, int[] hl)
          Constructor.
 
Method Summary
 Expr compile(QueryContext ctx, VarScope scp)
          Compiles and optimizes the expression, assigns data types and cardinalities.
 Expr copy(QueryContext ctx, VarScope scp, IntObjMap<Var> vs)
          Copies an expression.
 Item item(QueryContext ctx, InputInfo ii)
          Evaluates the expression and returns the resulting item or a null reference, if the expression yields an empty sequence.
 Expr optimize(QueryContext ctx, VarScope scp)
          Optimizes an already compiled expression without recompiling its sub-expressions.
 void plan(FElem plan)
          Creates an expression tree.
 java.lang.String toString()
           
 Value value(QueryContext ctx)
          Evaluates the expression and returns the resulting value.
 
Methods inherited from class org.basex.query.expr.Arr
accept, allAreValues, checkNoUp, checkUp, copyAll, count, exprSize, has, indexEquivalent, inline, removable, toString
 
Methods inherited from class org.basex.query.expr.ParseExpr
checkAdmin, checkAllUp, checkBinary, checkBln, checkColl, checkCreate, checkCtx, checkDbl, checkDBNode, checkEStr, checkEStr, checkFunc, checkItem, checkItr, checkItr, checkMap, checkNode, checkNode, checkNode, checkNoEmpty, checkNoneUp, checkNoUp, checkQNm, checkStr, checkStr, checkStrBin, checkType, checkWrite, compBln, copyType, ebv, iter, optPre, preEval, size, test, type
 
Methods inherited from class org.basex.query.expr.Expr
addText, compEbv, copy, hasFreeVars, indexAccessible, inlineAll, isEmpty, isFunction, isItem, isVacuous, isValue, iterable, markTailCalls, sameAs, uses, visitAll
 
Methods inherited from class org.basex.data.ExprInfo
addPlan, addPlan, description, info, planAttr, planElem
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait
 

Constructor Detail

PartFunc

public PartFunc(InputInfo ii,
                Expr fn,
                Expr[] arg,
                int[] hl)
Constructor.

Parameters:
ii - input info
fn - function expression
arg - argument expressions
hl - positions of the placeholders
Method Detail

compile

public Expr compile(QueryContext ctx,
                    VarScope scp)
             throws QueryException
Description copied from class: Expr
Compiles and optimizes the expression, assigns data types and cardinalities.

Overrides:
compile in class Arr
Parameters:
ctx - query context
scp - variable scope
Returns:
optimized expression
Throws:
QueryException - query exception

optimize

public Expr optimize(QueryContext ctx,
                     VarScope scp)
              throws QueryException
Description copied from class: Expr
Optimizes an already compiled expression without recompiling its sub-expressions.

Overrides:
optimize in class Expr
Parameters:
ctx - query context
scp - variable scope
Returns:
optimized expression
Throws:
QueryException - query exception

item

public Item item(QueryContext ctx,
                 InputInfo ii)
          throws QueryException
Description copied from class: Expr
Evaluates the expression and returns the resulting item or a null reference, if the expression yields an empty sequence. If this method is not overwritten, Expr.iter(org.basex.query.QueryContext) must be implemented by an expression, as it may be called by this method.

Overrides:
item in class ParseExpr
Parameters:
ctx - query context
ii - input info
Returns:
iterator
Throws:
QueryException - query exception

value

public Value value(QueryContext ctx)
            throws QueryException
Description copied from class: Expr
Evaluates the expression and returns the resulting value.

Overrides:
value in class ParseExpr
Parameters:
ctx - query context
Returns:
iterator
Throws:
QueryException - query exception

copy

public Expr copy(QueryContext ctx,
                 VarScope scp,
                 IntObjMap<Var> vs)
Description copied from class: Expr
Copies an expression. Will be useful for inlining functions, or for copying static queries.

Specified by:
copy in class Expr
Parameters:
ctx - query context
scp - variable scope for creating new variables
vs - mapping from old variable IDs to new variable copies
Returns:
copied expression

plan

public void plan(FElem plan)
Description copied from class: ExprInfo
Creates an expression tree.

Overrides:
plan in class Arr
Parameters:
plan - root element

toString

public java.lang.String toString()
Specified by:
toString in class ExprInfo