ABAP 7.40: using function 'segment' instead of command 'split'

The following coding has to be translated into ABAP 7.40:

DATA:

  source    TYPE string VALUE 'MARA-MATNR=12345',

  tabname   TYPE tabname,

  fieldname TYPE fieldname,

  attribute TYPE string.

  SPLIT:

    source AT '-'

           INTO tabname fieldname,

    fieldname AT '='

              into fieldname attribute.

  " RESULT: tabname = 'MARA', fieldname = 'MATNR', attribute = '12345' !

I do not understand the F1 help of "segment" functions' features....

appendix:

via trial & error:

tabname    = segment( val = source index = 1 sep = '-' ).
fieldname  = segment( val = segment( val = source index = 2 sep = '-' ) index = 1 sep = '=' ).
attribute  = segment( val = source index = 2 sep = '=' ).

any shorter codings?