[PATCH 1 of 3] formatter: add support for functions in json

[Yuya Nishihara]

On Mon, 29 Aug 2016 12:52:41 -0500, Mathias De Maré wrote:
> # HG changeset patch
> # User Mathias De Maré <mathias.demare at gmail.com>
> # Date 1472483920 -7200
> #      Mon Aug 29 17:18:40 2016 +0200
> # Node ID fb88d0c87c2746bd84983f1005ed83276c6e9c68
> # Parent  318e2b600b80e4ed3c6f37df46ec7544f60d4c0b
> formatter: add support for functions in json
> 
> Some extensions (like largefiles) assign functions to configuration entries.
> This was only possible without formatting so far.
> 
> diff --git a/mercurial/formatter.py b/mercurial/formatter.py
> --- a/mercurial/formatter.py
> +++ b/mercurial/formatter.py
> @@ -193,6 +193,8 @@
>      elif isinstance(v, (int, float)):
>          return str(v)
>      else:
> +        if callable(v):
> +            v = "<function %s>" % v.func_name

It should be stringified by the caller. A callable isn't always serializable,
and it would be actually called in templater.