[Libguestfs] [PATCH 3/3] builder: improve the handling of list formats

[Richard W.M. Jones]

On Mon, Jul 18, 2016 at 01:18:02PM +0200, Pino Toscano wrote:
> Store them directly in List_entries, an adding helper function to
> convert from string.
> 
> Also use Getopt.Symbol for them, so there is no need to manually reject
> invalid formats.
> ---
>  builder/cmdline.ml       | 21 +++++++++++----------
>  builder/cmdline.mli      |  2 +-
>  builder/list_entries.ml  | 19 ++++++++++++++++---
>  builder/list_entries.mli | 16 +++++++++++++++-
>  4 files changed, 43 insertions(+), 15 deletions(-)
> 
> diff --git a/builder/cmdline.ml b/builder/cmdline.ml
> index 846c2e3..0667994 100644
> --- a/builder/cmdline.ml
> +++ b/builder/cmdline.ml
> @@ -42,7 +42,7 @@ type cmdline = {
>    delete_on_failure : bool;
>    format : string option;
>    gpg : string;
> -  list_format : [`Short|`Long|`Json];
> +  list_format : List_entries.format;
>    memsize : int option;
>    network : bool;
>    ops : Customize_cmdline.ops;
> @@ -88,15 +88,13 @@ let parse_cmdline () =
>    let format = ref "" in
>    let gpg = ref "gpg" in
>  
> -  let list_format = ref `Short in
> -  let list_set_long () = list_format := `Long in
> +  let list_format = ref List_entries.Short in
> +  let list_set_long () = list_format := List_entries.Long in
>    let list_set_format arg =
> -    list_format := match arg with
> -    | "short" -> `Short
> -    | "long" -> `Long
> -    | "json" -> `Json
> -    | fmt ->
> -      error (f_"invalid --list-format type '%s', see the man page") fmt in
> +    (* Do not catch the Invalid_argument that list_format_of_string
> +     * throws on invalid input, as it is already checked by the
> +     * Getopt handling of Symbol. *)
> +    list_format := List_entries.list_format_of_string arg in
>  
>    let machine_readable = ref false in
>  
> @@ -118,6 +116,9 @@ let parse_cmdline () =
>    let sync = ref true in
>    let warn_if_partition = ref true in
>  
> +  let formats = List_entries.list_formats
> +  and formats_string = String.concat "|" List_entries.list_formats in
> +
>    let argspec = [
>      [ "--arch" ],    Getopt.Set_string ("arch", arch),        s_"Set the output architecture";
>      [ "--attach" ],  Getopt.String ("iso", attach_disk),     s_"Attach data disk/ISO during install";
> @@ -144,7 +145,7 @@ let parse_cmdline () =
>      [ "--gpg" ],    Getopt.Set_string ("gpg", gpg),          s_"Set GPG binary/command";
>      [ "-l"; "--list" ],        Getopt.Unit list_mode,        s_"List available templates";
>      [ "--long" ],    Getopt.Unit list_set_long,    s_"Shortcut for --list-format long";
> -    [ "--list-format" ], Getopt.String ("short|long|json", list_set_format),
> +    [ "--list-format" ], Getopt.Symbol (formats_string, formats, list_set_format),
>                                               s_"Set the format for --list (default: short)";
>      [ "--machine-readable" ], Getopt.Set machine_readable, s_"Make output machine readable";
>      [ "-m"; "--memsize" ],        Getopt.Int ("mb", set_memsize),        s_"Set memory size";
> diff --git a/builder/cmdline.mli b/builder/cmdline.mli
> index 854db61..a0517a2 100644
> --- a/builder/cmdline.mli
> +++ b/builder/cmdline.mli
> @@ -30,7 +30,7 @@ type cmdline = {
>    delete_on_failure : bool;
>    format : string option;
>    gpg : string;
> -  list_format : [`Short|`Long|`Json];
> +  list_format : List_entries.format;
>    memsize : int option;
>    network : bool;
>    ops : Customize_cmdline.ops;
> diff --git a/builder/list_entries.ml b/builder/list_entries.ml
> index 2f053e8..2a1aef4 100644
> --- a/builder/list_entries.ml
> +++ b/builder/list_entries.ml
> @@ -21,11 +21,24 @@ open Common_utils
>  
>  open Printf
>  
> +type format =
> +  | Short
> +  | Long
> +  | Json
> +
> +let list_formats = [ "short"; "long"; "json" ]
> +
> +let list_format_of_string = function
> +  | "short" -> Short
> +  | "long" -> Long
> +  | "json" -> Json
> +  | fmt -> invalid_arg fmt
> +
>  let rec list_entries ~list_format ~sources index =
>    match list_format with
> -  | `Short -> list_entries_short index
> -  | `Long -> list_entries_long ~sources index
> -  | `Json -> list_entries_json ~sources index
> +  | Short -> list_entries_short index
> +  | Long -> list_entries_long ~sources index
> +  | Json -> list_entries_json ~sources index
>  
>  and list_entries_short index =
>    List.iter (
> diff --git a/builder/list_entries.mli b/builder/list_entries.mli
> index a3f35d3..008b906 100644
> --- a/builder/list_entries.mli
> +++ b/builder/list_entries.mli
> @@ -16,4 +16,18 @@
>   * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
>   *)
>  
> -val list_entries : list_format:([ `Short | `Long | `Json ]) -> sources:Sources.source list -> Index.index -> unit
> +type format =
> +  | Short
> +  | Long
> +  | Json
> +
> +val list_formats : string list
> +(** The string representation of the available formats. *)
> +
> +val list_format_of_string : string -> format
> +(** Convert from a string to the corresponding format.
> +
> +    Throw [Invalid_argument] if the string does not match any
> +    valid format. *)
> +
> +val list_entries : list_format:format -> sources:Sources.source list -> Index.index -> unit
> -- 
> 2.7.4
> 

ACK, although it would be nice if you could either rebase these
on top of mine or review my getopt patches (v2).

Rich.

-- 
Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones
Read my programming and virtualization blog: http://rwmj.wordpress.com
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