Defined in file seqfeat.asn
C++ class: CDelta_item

Delta-item ::= SEQUENCE {
    seq CHOICE {
        literal Seq-literal,
        loc Seq-loc,
        this NULL --same location as variation-ref itself

    -- Multiplier allows representing a tandem, e.g.  ATATAT as AT*3
    -- This allows describing CNV/SSR where delta=self  with a
    -- multiplier which specifies the count of the repeat unit.

    multiplier          INTEGER OPTIONAL, --assumed 1 if not specified.
    multiplier-fuzz     Int-fuzz OPTIONAL,

    action INTEGER {

        -- replace len(seq) positions starting with location.start with seq
        morph      (0),

        -- go downstream by distance specified by multiplier (upstream if < 0),
        -- in genomic context.
        offset     (1),

        -- excise sequence at location
        -- if multiplier is specified, delete len(location)*multiplier
        -- positions downstream
        del-at     (2),

        -- insert seq before the location.start
        ins-before (3)

    } DEFAULT morph