Re: [Libguestfs] Re: factorization would be nice
Richard W.M. Jones wrote:
On Wed, Aug 12, 2009 at 09:15:31AM +0100, Richard W.M. Jones wrote:
> On Wed, Aug 12, 2009 at 10:07:16AM +0200, Jim Meyering wrote:
> > List.iter (
> > function
> > | Pathname n ->
> > pr " char *%s = args.%s;\n" n n;
> > pr " ABS_PATH (%s, goto done);\n" n;
> > | Device n ->
> > pr " char *%s = args.%s;\n" n n;
> > pr " RESOLVE_DEVICE (%s, goto done);" n;
> > | Dev_or_Path n ->
On thing to add here:
The 'n's in this code are all different bindings. So there's no way
to get a closure which captures the values of all 'n's.
Thus in other code (but not in this case) you could have written:
let pr_args () =
pr " char *%s = args.%s\n" n n
in
where the value of 'n' would be captured in the closure 'pr_args', and
not have to be given explicitly each time.
Thanks for the explanation.
Here's what I have now:
(match snd style with
| [] -> ()
| args ->
pr " memset (&args, 0, sizeof args);\n";
pr "\n";
pr " if (!xdr_guestfs_%s_args (xdr_in, &args)) {\n" name;
pr " reply_with_error (\"%%s: daemon failed to decode procedure
arguments\", \"%s\");\n" name;
pr " return;\n";
pr " }\n";
let pr_args n =
pr " char *%s = args.%s;\n" n n
in
List.iter (
function
| Pathname n ->
pr_args n;
pr " ABS_PATH (%s, goto done);\n" n;
| Device n ->
pr_args n;
pr " RESOLVE_DEVICE (%s, goto done);" n;
| Dev_or_Path n ->
pr_args n;
pr " REQUIRE_ROOT_OR_RESOLVE_DEVICE (%s, goto done);" n;
| String n -> pr_args n
| OptString n -> pr " %s = args.%s ? *args.%s : NULL;\n" n n n
| StringList n ->
pr " %s = realloc (args.%s.%s_val,\n" n n n;
pr " sizeof (char *) * (args.%s.%s_len+1));\n" n
n;
pr " if (%s == NULL) {\n" n;
pr " reply_with_perror (\"realloc\");\n";
pr " goto done;\n";
pr " }\n";
pr " %s[args.%s.%s_len] = NULL;\n" n n n;
pr " args.%s.%s_val = %s;\n" n n n;
| Bool n -> pr " %s = args.%s;\n" n n
| Int n -> pr " %s = args.%s;\n" n n
| FileIn _ | FileOut _ -> ()
) args;
pr "\n"
);