org.basex.query.func
Class FNGen

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.StandardFunc
                      extended by org.basex.query.func.FNGen

public final class FNGen
extends StandardFunc

Generating functions.

Author:
BaseX Team 2005-12, BSD License, Christian Gruen

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
FNGen(InputInfo ii, Function f, Expr[] e)
          Constructor.
 
Method Summary
 boolean accept(ASTVisitor visitor)
          Traverses this expression, notifying the visitor of declared and used variables, and checking the tree for other recursive properties.
 boolean has(Expr.Flag flag)
          Indicates if an expression has the specified compiler property.
 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.
 Iter iter(QueryContext ctx)
          Evaluates the expression and returns an iterator on the resulting items.
 boolean iterable()
          Returns true if the expression is iterable, i.e., if it will not contain any duplicate nodes and if all nodes will be are sorted.
protected  Expr opt(QueryContext ctx)
          Performs function specific optimizations.
static ANode parseXml(IO input, Context ctx, boolean frag)
          Returns a document node for the parsed XML input.
 Value value(QueryContext ctx)
          Evaluates the expression and returns the resulting value.
 
Methods inherited from class org.basex.query.func.StandardFunc
atom, bindings, cache, checkData, checkFile, compile, copy, dataLock, dateTimeToMs, description, encoding, isFunction, isVacuous, oneOf, optimize, plan, toString
 
Methods inherited from class org.basex.query.expr.Arr
allAreValues, checkNoUp, checkUp, copyAll, count, exprSize, 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, optPre, preEval, size, test, type
 
Methods inherited from class org.basex.query.expr.Expr
addText, compEbv, copy, hasFreeVars, indexAccessible, inlineAll, isEmpty, isItem, isValue, markTailCalls, sameAs, uses, visitAll
 
Methods inherited from class org.basex.data.ExprInfo
addPlan, addPlan, info, planAttr, planElem
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait
 

Constructor Detail

FNGen

public FNGen(InputInfo ii,
             Function f,
             Expr[] e)
Constructor.

Parameters:
ii - input info
f - function definition
e - arguments
Method Detail

iter

public Iter iter(QueryContext ctx)
          throws QueryException
Description copied from class: Expr
Evaluates the expression and returns an iterator on the resulting items. If this method is not overwritten, Expr.item(org.basex.query.QueryContext, org.basex.util.InputInfo) must be implemented by an expression, as it may be called by this method.

Overrides:
iter in class ParseExpr
Parameters:
ctx - query context
Returns:
resulting item
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

opt

protected Expr opt(QueryContext ctx)
            throws QueryException
Description copied from class: StandardFunc
Performs function specific optimizations.

Overrides:
opt in class StandardFunc
Parameters:
ctx - query context
Returns:
evaluated item
Throws:
QueryException - query exception

has

public boolean has(Expr.Flag flag)
Description copied from class: Expr
Indicates if an expression has the specified compiler property. This method is called by numerous Expr.compile(org.basex.query.QueryContext, org.basex.query.var.VarScope) methods to test properties of sub-expressions. It returns true if at least one test is successful.

Overrides:
has in class StandardFunc
Parameters:
flag - flag to be found
Returns:
result of check

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 Arr
Parameters:
visitor - visitor
Returns:
if the walk should be continued

iterable

public boolean iterable()
Description copied from class: Expr
Returns true if the expression is iterable, i.e., if it will not contain any duplicate nodes and if all nodes will be are sorted. The return value of this method is only relevant for node sequences. It is e.g. called by AxisPath.

Overrides:
iterable in class Expr
Returns:
result of check

parseXml

public static ANode parseXml(IO input,
                             Context ctx,
                             boolean frag)
                      throws java.io.IOException
Returns a document node for the parsed XML input.

Parameters:
input - string to be parsed
ctx - query context
frag - parse fragment
Returns:
result
Throws:
java.io.IOException - I/O exception