vm: print type names instead of numbers in fep

vm/debug.cpp

@@ -122,8 +122,8 @@ void factor_vm::print_nested_obj(cell obj, fixnum nesting)
 		std::cout << " ]";
 		break;
 	default:
-		std::cout << "#<type " << tagged<object>(obj).type() << " @ ";
-		std::cout << std::hex << obj << std::dec << ">";
+		std::cout << "#<" << type_name(tagged<object>(obj).type()) << " ";
+		std::cout << (void*)obj << ">";
 		break;
 	}
 }

vm/layouts.hpp

@@ -56,6 +56,44 @@ static const cell data_alignment = 16;
 
 #define TYPE_COUNT 14
 
+static inline const char *type_name(cell type)
+{
+	switch (type)
+	{
+	case FIXNUM_TYPE:
+		return "fixnum";
+	case F_TYPE:
+		return "f";
+	case ARRAY_TYPE:
+		return "array";
+	case FLOAT_TYPE:
+		return "float";
+	case QUOTATION_TYPE:
+		return "quotation";
+	case BIGNUM_TYPE:
+		return "bignum";
+	case ALIEN_TYPE:
+		return "alien";
+	case TUPLE_TYPE:
+		return "tuple";
+	case WRAPPER_TYPE:
+		return "wrapper";
+	case BYTE_ARRAY_TYPE:
+		return "byte-array";
+	case CALLSTACK_TYPE:
+		return "callstack";
+	case STRING_TYPE:
+		return "string";
+	case WORD_TYPE:
+		return "word";
+	case DLL_TYPE:
+		return "dll";
+	default:
+		assert(false);
+		return "";
+	}
+}
+
 enum code_block_type
 {
 	code_block_unoptimized,