LELCondition.h

Classes

LELCondition -- Class to make a mask from a condition. (full description)

template <class T> class LELCondition : public LELInterface<T>

Interface

Public Members

LELCondition (const CountedPtr<LELInterface<T> >& expr, const CountedPtr<LELInterface<Bool> >& cond)

~LELCondition()

virtual void eval (LELArray<T>& result, const Slicer& section) const

virtual LELScalar<T> getScalar() const

virtual Bool prepareScalarExpr()

virtual String className() const

virtual Bool lock (FileLocker::LockType, uInt nattempts)

virtual void unlock()

virtual Bool hasLock (FileLocker::LockType) const

virtual void resync()

Description

Review Status

Date Reviewed:: yyyy/mm/dd

Prerequisite

Etymology

This derived LEL letter class handles a condition as a mask.

Synopsis

This LEL letter class is derived from LELInterface. It is used to construct LEL objects that know how to deal with a condition (given using operator[]). The operands cannot be a scalar. The LELCondition object is embedded in the tree, and the conversion actually happens at tree evaluation time.

A description of the implementation details of the LEL classes can be found in Note 216

Example

Examples are not very useful as the user would never use these classes directly. Look in LatticeExprNode.cc to see how it invokes these classes. An example of how the user would indirectly use this class (through the envelope) is:

    IPosition shape(2,5,10);
    ArrayLattice<Float> x(shape); x.set(1.0);
    ArrayLattice<Double> y(shape); 
    y.copyData(x[x>5]);                 // y = x;

The LELCondition class is embedded in the tree at construction time so as to turn the condition in a mask on x.

Member Description

LELCondition (const CountedPtr<LELInterface<T> >& expr, const CountedPtr<LELInterface<Bool> >& cond)

Construct the condition on the given expression.

~LELCondition()

Destructor does nothing

virtual void eval (LELArray<T>& result, const Slicer& section) const

Recursively evaluate the expression.

virtual LELScalar<T> getScalar() const

Recursively evaluate the scalar

virtual Bool prepareScalarExpr()

Do further preparations (e.g. optimization) on the expression.

virtual String className() const

Get class name

virtual Bool lock (FileLocker::LockType, uInt nattempts)
virtual void unlock()
virtual Bool hasLock (FileLocker::LockType) const
virtual void resync()

Handle locking/syncing of a lattice in a lattice expression.