diff options
Diffstat (limited to 'lib.c')
| -rw-r--r-- | lib.c | 21 |
1 files changed, 17 insertions, 4 deletions
@@ -107,7 +107,7 @@ val numeric_error_s, range_error_s; val query_error_s, file_error_s, process_error_s, syntax_error_s; val timeout_error_s, system_error_s; val warning_s, defr_warning_s, restart_s, continue_s; -val gensym_counter_s, nullify_s, from_list_s, lambda_set_s; +val gensym_counter_s, nullify_s, from_list_s, lambda_set_s, length_s; val nothrow_k, args_k, colon_k, auto_k, fun_k; val wrap_k, reflect_k; @@ -9175,8 +9175,17 @@ val length(val seq) return hash_count(seq); if (seq->co.cls == carray_s) return length_carray(seq); - if (structp(seq) && maybe_slot(seq, car_s)) - return length_proper_list(nullify(seq)); + if (structp(seq)) { + val length_meth = maybe_slot(seq, length_s); + + if (length_meth) + return funcall1(length_meth, seq); + + if (maybe_slot(seq, car_s)) + return length_proper_list(nullify(seq)); + + type_mismatch(lit("length: ~s has no length or car method"), seq, nao); + } /* fallthrough */ default: type_mismatch(lit("length: ~s is not a sequence"), seq, nao); @@ -9204,7 +9213,10 @@ val empty(val seq) if (seq->co.cls == hash_s) return eq(hash_count(seq), zero); if (structp(seq)) { - val nullify_meth = maybe_slot(seq, nullify_s); + val length_meth = maybe_slot(seq, length_s); + val nullify_meth = if2(nilp(length_meth), maybe_slot(seq, nullify_s)); + if (length_meth) + return eq(funcall1(length_meth, seq), zero); return if3(nullify_meth && funcall1(nullify_meth, seq), nil, seq); } default: @@ -9946,6 +9958,7 @@ static void obj_init(void) nullify_s = intern(lit("nullify"), user_package); from_list_s = intern(lit("from-list"), user_package); lambda_set_s = intern(lit("lambda-set"), user_package); + length_s = intern(lit("length"), user_package); args_k = intern(lit("args"), keyword_package); nothrow_k = intern(lit("nothrow"), keyword_package); |