[Libguestfs] [PATCH] v2v: Make the interface between cmdline.ml and v2v.ml

[Pino Toscano]

On Tuesday 10 November 2015 20:00:56 Richard W.M. Jones wrote:
> I'm interested to hear opinions on whether this makes the code
> clearer, or not.

I'd say it does, indeed.

> This is virt-v2v, but many other virt-* tools work the same way, and
> analogous changes could be made.

+1 for applying the same on other OCaml tools.

> Currently when command line argument parsing is done in 'cmdline.ml'
> the list of parsed parameters is passed to the main program in a very
> long tuple.  Each parameter is strongly typed, but not named (so for
> example two 'bool' flags on the command line might be swapped
> accidentally).
> 
> This patch uses a struct to pass the parameters instead, so they are
> both strongly typed *and* named - two parameters with the same type
> could not be swapped by accident.
> 
> Also the type of each parameter is now defined in the struct 'type'
> definition, which also appears in a 'cmdline.mli' file.
> 
> In addition, in the main program it should be clearer where a
> particular variable comes from, ie. you have to write
> 'cmdline.output_alloc' instead of 'output_alloc', which may make it
> clearer that it comes from the command line '-oa' parameter, thus
> making the code easier to understand.

Sounds nice as approach -- why not adding also input and output to the
struct?

Thanks,
-- 
Pino Toscano
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