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" );