kc3-lang/kc3

diff --git a/ic3/.ic3_history b/ic3/.ic3_history
index 3d5db01..f7b7c47 100644
--- a/ic3/.ic3_history
+++ b/ic3/.ic3_history
@@ -7,3 +7,9 @@ quote %GL.Sphere{segments_u: 100}
 %GL.Sphere{segments_u: 100 + 1}
 %GL.Sphere{segments_u: (Uw) (100 + 1)}
 a = (U8) { 1, 2 }
+quote a[0]
+a[0]
+a = (U8) { 1, 2 }
+a[0]
+a = (U8) { 1, 2 }
+a[0]
diff --git a/libc3/array.c b/libc3/array.c
index af7533d..de87424 100644
--- a/libc3/array.c
+++ b/libc3/array.c
@@ -10,7 +10,7 @@
  * AUTHOR BE CONSIDERED LIABLE FOR THE USE AND PERFORMANCE OF
  * THIS SOFTWARE.
  */
-#include <assert.h>
+#include "assert.h"
 #include <stdlib.h>
 #include <string.h>
 #include <err.h>
@@ -128,21 +128,47 @@ s_array * array_data_set (s_array *a, const uw *address,
   return NULL;
 }
 
-s_tag * array_data_tag (s_tag *a, const s_tag *address, s_tag *dest)
+s_tag * array_data_tag (const s_tag *a, const s_tag *address,
+                        s_tag *dest)
 {
   void *a_data;
   f_init_copy init_copy;
   void *tmp_data;
   s_tag tmp = {0};
-  assert(a->type == TAG_ARRAY);
-  assert(address->type == TAG_ARRAY);
+  if (a->type != TAG_ARRAY) {
+    err_puts("array_data_tag: not an array");
+    assert(! "array_data_tag: not an array");
+    return NULL;
+  }
+  if (address->type != TAG_ARRAY) {
+    err_puts("array_data_tag: address: not an array");
+    assert(! "array_data_tag: address: not an array");
+    return NULL;
+  }
+  if (address->data.array.dimension != 1) {
+    err_puts("array_data_tag: address dimension != 1");
+    assert(! "array_data_tag: address dimension != 1");
+    return NULL;
+  }
+  if (address->data.array.dimensions[0].count !=
+      a->data.array.dimension) {
+    err_write_1("array_data_tag: address dimension mismatch: ");
+    err_inspect_uw(&address->data.array.dimensions[0].count);
+    err_write_1(" != ");
+    err_inspect_uw(&a->data.array.dimension);
+    err_write_1("\n");
+    assert(! "array_data_tag: address dimension mismatch");
+    return NULL;
+  }
   a_data = array_data(&a->data.array, address->data.array.data);
   if (a_data) {
     if (! sym_to_init_copy(a->data.array.type, &init_copy) ||
         ! sym_to_tag_type(a->data.array.type, &tmp.type) ||
         ! tag_to_pointer(&tmp, a->data.array.type, &tmp_data) ||
-        ! init_copy(tmp_data, a_data))
+        (init_copy &&
+         ! init_copy(tmp_data, a_data)))
       return NULL;
+    *dest = tmp;
     return dest;
   }
   return NULL;
diff --git a/libc3/array.h b/libc3/array.h
index affc415..f6f8fab 100644
--- a/libc3/array.h
+++ b/libc3/array.h
@@ -26,7 +26,7 @@ s_array * array_init_copy (s_array *a, const s_array *src);
 /* Observers */
 s_str *            array_inspect (const s_array *array, s_str *dest);
 void *             array_data (const s_array *a, const uw *address);
-s_tag *            array_data_tag (s_tag *a, const s_tag *address,
+s_tag *            array_data_tag (const s_tag *a, const s_tag *address,
                                    s_tag *dest);
 
 /* Operators */
diff --git a/libc3/tag.c b/libc3/tag.c
index 0357cea..73c2c09 100644
--- a/libc3/tag.c
+++ b/libc3/tag.c
@@ -211,7 +211,7 @@ void tag_clean (s_tag *tag)
   }
 }
 
-s_tag * tag_brackets (s_tag *tag, const s_tag *address,
+s_tag * tag_brackets (const s_tag *tag, const s_tag *address,
                       s_tag *dest)
 {
   assert(tag);
diff --git a/libc3/tag.h b/libc3/tag.h
index 55ff36d..33304d3 100644
--- a/libc3/tag.h
+++ b/libc3/tag.h
@@ -20,7 +20,6 @@
 #define LIBC3_TAG_H
 
 #include <stdarg.h>
-#include <stdio.h>
 #include "tag_init.h"
 #include "tag_type.h"
 
@@ -76,7 +75,8 @@ bool *  tag_and (const s_tag *a, const s_tag *b, bool *dest);
 s_tag * tag_band (const s_tag *a, const s_tag *b, s_tag *dest);
 s_tag * tag_bnot (const s_tag *tag, s_tag *dest);
 s_tag * tag_bor (const s_tag *a, const s_tag *b, s_tag *dest);
-s_tag * tag_brackets (s_tag *tag, const s_tag *address, s_tag *dest);
+s_tag * tag_brackets (const s_tag *tag, const s_tag *address,
+                      s_tag *dest);
 s_tag * tag_bxor (const s_tag *a, const s_tag *b, s_tag *dest);
 s_tag * tag_div (const s_tag *a, const s_tag *b, s_tag *dest);
 bool *  tag_lt (const s_tag *a, const s_tag *b, bool *dest);