add registry of vector constructors, make-generalized-vector

* libguile/generalized-vectors.h:
* libguile/generalized-vectors.c: Add a registry of vector constructors.
  (scm_make_generalized_vector): New public function, constructs a
  vector of a given type.

* libguile/bitvectors.c:
* libguile/bytevectors.c:
* libguile/srfi-4.c:
* libguile/strings.c:
* libguile/vectors.c: Register vector constructors.

* libguile/extensions.c (scm_init_extensions): No need to NULL the list
  of registered extensions here, the static init does it for us. Allows
  scm_c_register_extension to be called before scm_init_extensions.

* libguile/init.c (scm_i_init_guile): Move array initialization earlier,
  so e.g. scm_init_strings has access to a valid list of array element
  types when registering its vector constructor.

1 files changed, 37 insertions, 0 deletions

diff --git a/libguile/generalized-vectors.c b/libguile/generalized-vectors.c
index 0c85f368a..2d437a475 100644
--- a/libguile/generalized-vectors.c
+++ b/libguile/generalized-vectors.c
@@ -31,6 +31,43 @@
 #include "libguile/generalized-vectors.h"
 
 
+struct scm_t_vector_ctor
+{
+  SCM tag;
+  SCM (*ctor)(SCM, SCM);
+};
+
+#define VECTOR_CTORS_N_STATIC_ALLOC 20
+static struct scm_t_vector_ctor vector_ctors[VECTOR_CTORS_N_STATIC_ALLOC];
+static int num_vector_ctors_registered = 0;
+
+void
+scm_i_register_vector_constructor (SCM type, SCM (*ctor)(SCM, SCM))
+{
+  if (num_vector_ctors_registered >= VECTOR_CTORS_N_STATIC_ALLOC)
+    /* need to increase VECTOR_CTORS_N_STATIC_ALLOC, buster */
+    abort ();
+  else
+    { 
+      vector_ctors[num_vector_ctors_registered].tag = type;
+      vector_ctors[num_vector_ctors_registered].ctor = ctor;
+      num_vector_ctors_registered++;
+    }
+}
+
+SCM_DEFINE (scm_make_generalized_vector, "make-generalized-vector", 2, 1, 0,
+            (SCM type, SCM len, SCM fill),
+            "Make a generalized vector")
+#define FUNC_NAME s_scm_make_generalized_vector
+{
+  int i;
+  for (i = 0; i < num_vector_ctors_registered; i++)
+    if (vector_ctors[i].tag == type)
+      return vector_ctors[i].ctor(len, fill);
+  scm_wrong_type_arg_msg (FUNC_NAME, SCM_ARG1, type, "array type");
+}
+#undef FUNC_NAME
+
 int
 scm_is_generalized_vector (SCM obj)
 {