SAValue

Metafunction

SAValue

The default alphabet type of a suffix array, i.e. the type to store a position of a string or string set.

SAValue<TObject>::Type

Parameters

TObject

A string, string set, or index type.

Types: Index, String, StringSet

Return Values

A type to store a position.

If TObject is a String, it is a single integer value. By default this is the Size type of TObject.

If TObject is a StringSet, it could be a single integer too (called global position, see ConcatDirect) or a Pair (called local position, see Owner). Currently SeqAn defaults to a local position for StringSet classes (index_base.h):

template < typename TString, typename TSpec >
struct SAValue< StringSet<TString, TSpec> > {
    typedef Pair<
        typename Size< StringSet<TString, TSpec> >::Type,
        typename SAValue<TString>::Type,
        Compressed
    > Type;
};

Remarks

Note: SAValue is the return type of various function, e.g. position for the Index Finder class, getOccurrence, getOccurrences etc. You should always use the type of this meta-function to store the return values. If you want to write algorithms for both variants (local and global positions) you should use the functions posLocalize, posGlobalize, getSeqNo and getSeqOffset.

Note: If TObject is an Index, Position returns the same value as SAValue. You can change the position type of an index by overloading SAValue, not Position.