jazz_bebop::ColSelection Class Reference

ColSelection: A selection of columns from a Space. More...

#include <space.h>

Public Member Functions
	ColSelection (pChar query, pSpace p_space)
	The constructor for a ColSelection.
virtual bool	restart ()
	ColSelection: Restart the iterator.
virtual int	next_index ()
	ColSelection: Get the next column index.
virtual pName	next_name ()
	ColSelection: Get the next column name.

Data Fields
bool	is_valid = false
	True if the iterator was created by a successful query.

Private Attributes
int	current_col = 0
	The index of the current column (the next to be retrieved).
stdNames	name = {}
	The list of column names in the selection.
std::vector< int >	index = {}
	The list of column indices in the selection.

Detailed Description

ColSelection: A selection of columns from a Space.

The interface is consistent with RowSelection, but unlike RowSelection the parent class is probably all you need.

See also

Space

Constructor & Destructor Documentation

ColSelection()

jazz_bebop::ColSelection::ColSelection	(	pChar	query,
		pSpace	p_space
	)

The constructor for a ColSelection.

The constructor will parse the query and create a list of column names and indices. These will not change during the lifetime of the object.

Parameters

query	By default, a list of comma separated column names. A descendant may define a different interface. In Bop, this is the content of a SELECT clause.
p_space	The Space that created the object is required to call col_index().

Member Function Documentation

restart()

bool jazz_bebop::ColSelection::restart ( )

virtual

ColSelection: Restart the iterator.

Returns

true if successful, false failed or was already pointing to the first element.

next_index()

int jazz_bebop::ColSelection::next_index ( )

virtual

ColSelection: Get the next column index.

Returns

The next column index or -i if the iteration is exhausted.

next_name()

pName jazz_bebop::ColSelection::next_name ( )

virtual

ColSelection: Get the next column name.

Returns

The next column name or nullptr if the iteration is exhausted.

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The documentation for this class was generated from the following files:

• space.h
• space.cpp