Re: Uniform vectors, user survey

[Marius Vollmer <marius.vollmer@uni-dortmund.de>]

Marius Vollmer <marius.vollmer@uni-dortmund.de> writes:

> I have close to zero experience with using uniform vectors myself, so
> I appreciate your input.

Thanks everybody for answering!

Here is where I am heading at the moment:

- The old uniform vector implementation are gone and the SRFI-4
  homogenous vectors have taken over.  This means that a bunch of
  precious tc7 types are freed.

  This brings some non-compatible changes to the C side, which I think
  are reasonable.  You can no longer use SCM_UVECTOR_BASE etc and of
  course the tc7 tag messing is no longer needed.

- The C API of the SRFI-4 homogenous vectors has the two functions
  scm_TAGvector_elements and scm_uniform_vector_release that allow
  access to the raw memory of the vector.  There is scm_take_TAGvector
  to have Guile take over a memory block.

- Read and print syntax for arrays has been extended to also accept
  the new "u8" etc tags and Guile can now print and read arrays with
  non-zero lower bounds:

    (make-array 0 '(1 2) '(2 3))
    => #2@1@2((0 0) (0 0))

  The "@1@2" means that the lower bounds are 1 and 2, respectively.

- The prototypes will be deprecated.  Instead, make-uniform-array will
  take a creator procedure; i.e, to get a u8 array you would do

    (make-uniform-array make-u8vector 2 2)
    => #2u8((220 88) (48 64))

  The array will not be initialized.  You can use uniform-array-fill!
  for that.

  In place of array-prototype, which is deprecated, there is the new
  array-creator.

- In addition to the types specified in SRFI-4, Guile also has c32 and
  c64, which are floating point complex numbers of single and double
  precision.

- vector? will be true for all zero-origin, one-dimensional arrays,
  including uniform arrays except strings, bit vectors and suitable
  shared arrays.  Strings can be used with make-uniform-array but are
  not accepted by vector? because R5RS says so.  Also, vector-ref etc
  will be suitably extended.

  (Not implemented yet.  This breaks with the tradition of RnRS to
  have disjoint types.  Maybe uniform vectors and general vectors
  should remain disjoint?  Opinions?)

- There will be some form of nice C API for uniform arrays.


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