Hello, version 2.2 of Guile will (I hope) include rank-polymorphic versions of array-ref, array-set! and array-for-each. What this means is that instead of requiring as many indices as the rank of the array, with these functions you can give fewer indices and get a subarray (a ‘prefix slice’). If you give all the indices, they behave just as the current versions.
My original intention was for these functions to replace array-ref and array-set!. That's how a number of array languages/libraries do it (numpy, to mention a popular one. You don't need to say A[i, :, :], you can just say A[i].). However, the maintainers spoke against this, so these functions need different names. The names I chose are array-from, array-amend! and array-for-each-cell. These names are taken from the J docs (http://www.jsoftware.com/help/dictionary/d520.htm, http://www.jsoftware.com/help/dictionary/d530n.htm), because the behavior is based on J and I consider J to be ‘the source’ when it comes to these concepts. civodul has proposed array-slice instead of array-from. However, array-from only returns a slice when the rank of the result would be positive. wingo has pointed out that it is unusual to have a function name ending in a preposition. What do *you* think should be the names of these functions? Thanks, lloda PS: The justification for these functions is given in the documentation, but in short: 1) other than the creation of the subarray descriptors, they don't cost any more than the rank-strict versions, 2) the only way to reproduce them in current Guile is with make-shared-array, which is very slow and cumbersome, 3) they recover a functionality that used to be part of Guile but was removed (‘enclosed arrays’). PPS: You can check out the functions at http://git.savannah.gnu.org/gitweb/?p=guile.git;a=shortlog;h=refs/heads/lloda-squash1. I rebase this branch on master periodically. The maintainers have reviewed it, but any extra reviews would of course be appreciated, especially of the doc.
