Advanced Programming Guide

362 • Appendix A: Internal Representation and ManipulationThe flags field is a bit field containing the following sub-fields:• data type - 5 bits - indicates one of several hardware datatypes orthat a Maple data type (as specified by maple-type) is being used.• sub type - 2 bits - indicates if the RTABLE is an Array, Matrix, orVector.• storage - 4 bits - describes the storage layout (e.g. sparse, upper triangular,etc.)• order - 1 bit - indicates C or Fortran ordering of RTABLE elements.• read only - 1 bit - indicates the RTABLE is to be read-only once created.• foreign - 1 bit - indicates that the space pointed to by the data fielddoes not belong to Maple, so Maple should not garbage collect it.• number of dimensions - 6 bits - the number of dimensions of theRTABLE, from 0 to 63.The num-elems field indicates the total number of elements of storageallocated for the data. For a Maple-sparse RTABLE, num-elems isnot used. For a NAG-sparse RTABLE, num-elems specifies the number ofelements currently allocated, some of which might not be in use.The remaining fields specify the upper and lower bounds of each dimension,and are stored directly as signed machine integers. The limitson bounds are −2, 147, 483, 648 to 2, 147, 483, 647 for 32-bit architecturesand −9, 223, 372, 036, 854, 775, 808 to 9, 223, 372, 036, 854, 775, 807 for 64-bit architectures. The total number of elements cannot exceed the upperlimit numbers either.Save StatementSAVE∧ expr − seqMaple syntax: save expr, expr, ...Length: 2The Maple save statement. The expression sequence gives a list ofnames of objects to save, and either a file name or repository name inwhich to save them. The file or repository name can be specified as aNAME or STRING.