Handle structs in list collection operations.

This eliminates the error which occurs when
a sequence implemented as a struct is nconced
or appended onto. The struct is converted to
a list, and so is the object on the right hand
side. As a result, more generic sequence code
works on structs.

* lib.c (list_collect_nconc, list_collect_append):
Handle tail of type COBJ by converting to a list,
storing that list back in the tail and then
destructively tacking onto that the obj
operand, also turned into a list.

1 files changed, 10 insertions, 0 deletions

diff --git a/lib.c b/lib.c
index 8807a189..c734324b 100644
--- a/lib.c
+++ b/lib.c
@@ -803,6 +803,11 @@ loc list_collect_nconc(loc ptail, val obj)
   case LSTR:
     replace_str(tailobj, obj, t, t);
     return ptail;
+  case COBJ:
+    set(ptail, tolist(tailobj));
+    ptail = tail(deref(ptail));
+    set(ptail, tolist(obj));
+    return ptail;
   default:
     uw_throwf(error_s, lit("cannot nconc ~s to ~s"), obj, tailobj, nao);
   }
@@ -833,6 +838,11 @@ loc list_collect_append(loc ptail, val obj)
     set(ptail, copy_str(tailobj));
     replace_str(deref(ptail), obj, t, t);
     return ptail;
+  case COBJ:
+    set(ptail, tolist(tailobj));
+    ptail = tail(deref(ptail));
+    set(ptail, tolist(obj));
+    return ptail;
   default:
     uw_throwf(error_s, lit("cannot append to ~s"), tailobj, nao);
   }