New functions array-from, array-from*, array-amend!

* libguile/arrays.h (scm_array_from, scm_array_from_s,
  scm_array_amend_x): New declarations.

* libguile/arrays.c (scm_array_from, scm_array_from_s,
  scm_array_amend_x): New functions, export as array-from, array-from*,
  array-amend!.

* test-suite/tests/arrays.test: Tests for array-from, array-from*,
  array-amend!. Replace with-test-prefix/c&e with with-test-prefix where
  the array read syntax isn't used.

3 files changed, 290 insertions, 4 deletions

diff --git a/libguile/arrays.c b/libguile/arrays.c
index b8307d528..395bb6723 100644
--- a/libguile/arrays.c
+++ b/libguile/arrays.c
@@ -28,7 +28,6 @@
 #include <stdio.h>
 #include <errno.h>
 #include <string.h>
-#include <assert.h>
 
 #include "verify.h"
 
@@ -474,6 +473,178 @@ SCM_DEFINE (scm_make_shared_array, "make-shared-array", 2, 0, 1,
 #undef FUNC_NAME
 
 
+static void
+array_from_pos (scm_t_array_handle *handle, size_t *ndim, size_t *k, SCM *i, ssize_t *pos,
+                scm_t_array_dim **s, char const * FUNC_NAME, SCM error_args)
+{
+  *s = scm_array_handle_dims (handle);
+  *k = *ndim = scm_array_handle_rank (handle);
+  for (; *k>0 && scm_is_pair (*i); --*k, ++*s, *i=scm_cdr (*i))
+    {
+      ssize_t ik = scm_to_ssize_t (scm_car (*i));
+      if (ik<(*s)->lbnd || ik>(*s)->ubnd)
+        {
+          scm_array_handle_release (handle);
+          scm_misc_error (FUNC_NAME, "indices out of range", error_args);
+        }
+      *pos += (ik-(*s)->lbnd) * (*s)->inc;
+    }
+}
+
+static void
+array_from_get_o (scm_t_array_handle *handle, size_t k, scm_t_array_dim *s, ssize_t pos,
+                  SCM *o)
+{
+  scm_t_array_dim * os;
+  *o = scm_i_make_array (k);
+  SCM_I_ARRAY_SET_V (*o, handle->vector);
+  SCM_I_ARRAY_SET_BASE (*o, pos + handle->base);
+  os = SCM_I_ARRAY_DIMS (*o);
+  for (; k>0; --k, ++s, ++os)
+    {
+      os->ubnd = s->ubnd;
+      os->lbnd = s->lbnd;
+      os->inc = s->inc;
+    }
+}
+
+SCM_DEFINE (scm_array_from_s, "array-from*", 1, 0, 1,
+           (SCM ra, SCM indices),
+            "Return the array slice @var{ra}[@var{indices} ..., ...]\n"
+            "The rank of @var{ra} must equal to the number of indices or larger.\n\n"
+            "See also @code{array-ref}, @code{array-from}, @code{array-amend!}.\n\n"
+            "@code{array-from*} may return a rank-0 array. For example:\n"
+            "@lisp\n"
+            "(array-from* #2((1 2 3) (4 5 6)) 1 1) @result{} #0(5)\n"
+            "(array-from* #2((1 2 3) (4 5 6)) 1) @result{} #(4 5 6)\n"
+            "(array-from* #2((1 2 3) (4 5 6))) @result{} #2((1 2 3) (4 5 6))\n"
+            "(array-from* #0(5) @result{} #0(5).\n"
+            "@end lisp")
+#define FUNC_NAME s_scm_array_from_s
+{
+  SCM o, i = indices;
+  size_t ndim, k;
+  ssize_t pos = 0;
+  scm_t_array_handle handle;
+  scm_t_array_dim *s;
+  scm_array_get_handle (ra, &handle);
+  array_from_pos (&handle, &ndim, &k, &i, &pos, &s, FUNC_NAME, scm_list_2 (ra, indices));
+  if (k==ndim)
+    o = ra;
+  else if (scm_is_null (i))
+    {
+      array_from_get_o(&handle, k, s, pos, &o);
+    }
+  else
+    {
+      scm_array_handle_release (&handle);
+      scm_misc_error(FUNC_NAME, "too many indices", scm_list_2 (ra, indices));
+    }
+  scm_array_handle_release (&handle);
+  return o;
+}
+#undef FUNC_NAME
+
+
+SCM_DEFINE (scm_array_from, "array-from", 1, 0, 1,
+           (SCM ra, SCM indices),
+            "Return the element at the @code{(@var{indices} ...)} position\n"
+            "in array @var{ra}, or the array slice @var{ra}[@var{indices} ..., ...]\n"
+            "if the rank of @var{ra} is larger than the number of indices.\n\n"
+            "See also @code{array-ref}, @code{array-from*}, @code{array-amend!}.\n\n"
+            "@code{array-from} never returns a rank 0 array. For example:\n"
+            "@lisp\n"
+            "(array-from #2((1 2 3) (4 5 6)) 1 1) @result{} 5\n"
+            "(array-from #2((1 2 3) (4 5 6)) 1) @result{} #(4 5 6)\n"
+            "(array-from #2((1 2 3) (4 5 6))) @result{} #2((1 2 3) (4 5 6))\n"
+            "(array-from #0(5) @result{} 5.\n"
+            "@end lisp")
+#define FUNC_NAME s_scm_array_from
+{
+  SCM o, i = indices;
+  size_t ndim, k;
+  ssize_t pos = 0;
+  scm_t_array_handle handle;
+  scm_t_array_dim *s;
+  scm_array_get_handle (ra, &handle);
+  array_from_pos (&handle, &ndim, &k, &i, &pos, &s, FUNC_NAME, scm_list_2 (ra, indices));
+  if (k>0)
+    {
+      if (k==ndim)
+        o = ra;
+      else
+        array_from_get_o(&handle, k, s, pos, &o);
+    }
+  else if (scm_is_null(i))
+    o = scm_array_handle_ref (&handle, pos);
+  else
+    {
+      scm_array_handle_release (&handle);
+      scm_misc_error(FUNC_NAME, "too many indices", scm_list_2 (ra, indices));
+    }
+  scm_array_handle_release (&handle);
+  return o;
+}
+#undef FUNC_NAME
+
+
+SCM_DEFINE (scm_array_amend_x, "array-amend!", 2, 0, 1,
+            (SCM ra, SCM b, SCM indices),
+            "Set the array slice @var{ra}[@var{indices} ..., ...] to @var{b}\n."
+            "Equivalent to @code{(array-copy! @var{b} (apply array-from @var{ra} @var{indices}))}\n"
+            "if the number of indices is smaller than the rank of @var{ra}; otherwise\n"
+            "equivalent to @code{(apply array-set! @var{ra} @var{b} @var{indices})}.\n"
+            "This function returns the modified array @var{ra}.\n\n"
+            "See also @code{array-ref}, @code{array-from}, @code{array-from*}.\n\n"
+            "For example:\n"
+            "@lisp\n"
+            "(define A (list->array 2 '((1 2 3) (4 5 6))))\n"
+            "(array-amend! A #0(99) 1 1) @result{} #2((1 2 3) (4 #0(99) 6))\n"
+            "(array-amend! A 99 1 1) @result{} #2((1 2 3) (4 99 6))\n"
+            "(array-amend! A #(a b c) 0) @result{} #2((a b c) (4 99 6))\n"
+            "(array-amend! A #2((x y z) (9 8 7))) @result{} #2((x y z) (9 8 7))\n\n"
+            "(define B (make-array 0))\n"
+            "(array-amend! B 15) @result{} #0(15)\n"
+            "@end lisp")
+#define FUNC_NAME s_scm_array_amend_x
+{
+  SCM o, i = indices;
+  size_t ndim, k;
+  ssize_t pos = 0;
+  scm_t_array_handle handle;
+  scm_t_array_dim *s;
+  scm_array_get_handle (ra, &handle);
+  array_from_pos (&handle, &ndim, &k, &i, &pos, &s, FUNC_NAME, scm_list_3 (ra, b, indices));
+  if (k>0)
+    {
+      if (k==ndim)
+        o = ra;
+      else
+        array_from_get_o(&handle, k, s, pos, &o);
+      scm_array_handle_release(&handle);
+      /* an error is still possible here if o and b don't match. */
+      /* FIXME copying like this wastes the handle, and the bounds matching
+         behavior of array-copy! is not strict. */
+      scm_array_copy_x(b, o);
+    }
+  else if (scm_is_null(i))
+    {
+      scm_array_handle_set (&handle, pos, b);  /* ra may be non-ARRAYP */
+      scm_array_handle_release (&handle);
+    }
+  else
+    {
+      scm_array_handle_release (&handle);
+      scm_misc_error(FUNC_NAME, "too many indices", scm_list_3 (ra, b, indices));
+    }
+  return ra;
+}
+#undef FUNC_NAME
+
+
+#undef ARRAY_FROM_GET_O
+
+
 /* args are RA . DIMS */
 SCM_DEFINE (scm_transpose_array, "transpose-array", 1, 0, 1,
            (SCM ra, SCM args),
diff --git a/libguile/arrays.h b/libguile/arrays.h
index a5cd43dc2..977d30760 100644
--- a/libguile/arrays.h
+++ b/libguile/arrays.h
@@ -43,12 +43,18 @@ SCM_API SCM scm_make_typed_array (SCM type, SCM fill, SCM bounds);
 SCM_API SCM scm_from_contiguous_typed_array (SCM type, SCM bounds,
                                              const void *bytes,
                                              size_t byte_len);
+
 SCM_API SCM scm_shared_array_root (SCM ra);
 SCM_API SCM scm_shared_array_offset (SCM ra);
 SCM_API SCM scm_shared_array_increments (SCM ra);
+
 SCM_API SCM scm_make_shared_array (SCM oldra, SCM mapfunc, SCM dims);
 SCM_API SCM scm_transpose_array (SCM ra, SCM args);
 SCM_API SCM scm_array_contents (SCM ra, SCM strict);
+SCM_API SCM scm_array_from_s (SCM ra, SCM indices);
+SCM_API SCM scm_array_from (SCM ra, SCM indices);
+SCM_API SCM scm_array_amend_x (SCM ra, SCM b, SCM indices);
+
 SCM_API SCM scm_list_to_array (SCM ndim, SCM lst);
 SCM_API SCM scm_list_to_typed_array (SCM type, SCM ndim, SCM lst);
 
diff --git a/test-suite/tests/arrays.test b/test-suite/tests/arrays.test
index 4e26f4c43..57c5cef3e 100644
--- a/test-suite/tests/arrays.test
+++ b/test-suite/tests/arrays.test
@@ -296,6 +296,115 @@
       (and (eqv? 5 (array-ref s2 1))
 	   (eqv? 8 (array-ref s2 2))))))
 
+
+;;;
+;;; array-from*
+;;;
+
+(with-test-prefix/c&e "array-from*"
+
+  (pass-if "vector I"
+    (let ((v (vector 1 2 3)))
+      (array-fill! (array-from* v 1) 'a)
+      (array-equal? v #(1 a 3))))
+
+  (pass-if "vector II"
+    (let ((v (vector 1 2 3)))
+      (array-copy! #(a b c) (array-from* v))
+      (array-equal? v #(a b c))))
+
+  (pass-if "array I"
+    (let ((a (list->array 2 '((1 2 3) (4 5 6)))))
+      (array-fill! (array-from* a 1 1) 'a)
+      (array-equal? a #2((1 2 3) (4 a 6)))))
+
+  (pass-if "array II"
+    (let ((a (list->array 2 '((1 2 3) (4 5 6)))))
+      (array-copy! #(a b c) (array-from* a 1))
+      (array-equal? a #2((1 2 3) (a b c)))))
+
+  (pass-if "array III"
+    (let ((a (list->array 2 '((1 2 3) (4 5 6)))))
+      (array-copy! #2((a b c) (x y z)) (array-from* a))
+      (array-equal? a #2((a b c) (x y z)))))
+
+  (pass-if "rank 0 array"
+    (let ((a (make-array 77)))
+      (array-fill! (array-from* a) 'a)
+      (array-equal? a #0(a)))))
+
+
+;;;
+;;; array-from
+;;;
+
+(with-test-prefix/c&e "array-from"
+
+  (pass-if "vector I"
+    (let ((v (vector 1 2 3)))
+      (equal? 2 (array-from v 1))))
+
+  (pass-if "vector II"
+    (let ((v (vector 1 2 3)))
+      (array-copy! #(a b c) (array-from v))
+      (array-equal? v #(a b c))))
+
+  (pass-if "array I"
+    (let ((a (list->array 2 '((1 2 3) (4 5 6)))))
+      (equal? 5 (array-from a 1 1))))
+
+  (pass-if "array II"
+    (let ((a (list->array 2 '((1 2 3) (4 5 6)))))
+      (array-copy! #(a b c) (array-from a 1))
+      (array-equal? a #2((1 2 3) (a b c)))))
+
+  (pass-if "array III"
+    (let ((a (list->array 2 '((1 2 3) (4 5 6)))))
+      (array-copy! #2((a b c) (x y z)) (array-from a))
+      (array-equal? a #2((a b c) (x y z)))))
+
+  (pass-if "rank 0 array"
+    (let ((a (make-array 77)))
+      (equal? (array-from a) 77))))
+
+
+;;;
+;;; array-amend!
+;;;
+
+(with-test-prefix/c&e "array-amend!"
+
+  (pass-if "vector I"
+    (let ((v (vector 1 2 3)))
+      (and (eq? v (array-amend! v 'x 1))
+           (array-equal? v #(1 x 3)))))
+
+  (pass-if "vector II"
+    (let ((v (vector 1 2 3)))
+      (and (eq? v (array-amend! (array-from v) #(a b c)))
+           (array-equal? v #(a b c)))))
+
+  (pass-if "array I"
+    (let ((a (list->array 2 '((1 2 3) (4 5 6)))))
+      (and (eq? a (array-amend! a 'x 1 1))
+           (array-equal? a #2((1 2 3) (4 x 6))))))
+
+  (pass-if "array II"
+    (let ((a (list->array 2 '((1 2 3) (4 5 6)))))
+      (and (eq? a (array-amend! a #(a b c) 1))
+           (array-equal? a #2((1 2 3) (a b c))))))
+
+  (pass-if "array III"
+    (let ((a (list->array 2 '((1 2 3) (4 5 6)))))
+      (and (eq? a (array-amend! a #2((a b c) (x y z))))
+           (array-equal? a #2((a b c) (x y z))))))
+
+  (pass-if "rank 0 array"
+    (let ((a (make-array 77)))
+      (and (eq? a (array-amend! a 99))
+           (array-equal? a #0(99))))))
+
+
 ;;;
 ;;; array-contents
 ;;;
@@ -436,7 +545,7 @@
 ;;; shared-array-increments
 ;;;
 
-(with-test-prefix/c&e "shared-array-increments"
+(with-test-prefix "shared-array-increments"
 
   (pass-if "plain vector"
     (equal? '(1) (shared-array-increments (make-vector 4 0))))
@@ -595,7 +704,7 @@
 ;;; array-in-bounds?
 ;;;
 
-(with-test-prefix/c&e "array-in-bounds?"
+(with-test-prefix "array-in-bounds?"
 
   (pass-if (let ((a (make-array #f '(425 425))))
 	     (eq? #f (array-in-bounds? a 0)))))
@@ -606,7 +715,7 @@
 
 (with-test-prefix "array-type"
 
-  (with-test-prefix/c&e "on make-foo-vector"
+  (with-test-prefix "on make-foo-vector"
 
     (pass-if "bool"
       (eq? 'b (array-type (make-bitvector 1))))