[PATCH 5 of 5 V2] templater: port pad() to take keyword arguments

[Ryan McElroy]

On 4/8/17 2:06 PM, Yuya Nishihara wrote:
> # HG changeset patch
> # User Yuya Nishihara <yuya at tcha.org>
> # Date 1491225832 -32400
> #      Mon Apr 03 22:23:52 2017 +0900
> # Node ID 4519938b18da898cb116a3fea0d1ecee604266c0
> # Parent  05be4b2679b557c9fc8711d9b258e3667cec0b88
> templater: port pad() to take keyword arguments

Overall, I really like the direction of this series. Having keyword 
arguments will allow more clear template definitions.

I have only a few nit-picks and questions inline in a couple of the 
patches. I'll mark as "under review" pending a response.

>
> This is another example where keyword arguments can be actually useful.
>
> diff --git a/mercurial/templater.py b/mercurial/templater.py
> --- a/mercurial/templater.py
> +++ b/mercurial/templater.py
> @@ -589,29 +589,30 @@ def formatnode(context, mapping, args):
>           return node
>       return templatefilters.short(node)
>   
> - at templatefunc('pad(text, width[, fillchar=\' \'[, left=False]])')
> + at templatefunc('pad(text, width[, fillchar=\' \'[, left=False]])',
> +              argspec='text width fillchar left')
>   def pad(context, mapping, args):
>       """Pad text with a
>       fill character."""
> -    if not (2 <= len(args) <= 4):
> +    if 'text' not in args or 'width' not in args:
>           # i18n: "pad" is a keyword
>           raise error.ParseError(_("pad() expects two to four arguments"))
>   
> -    width = evalinteger(context, mapping, args[1],
> +    width = evalinteger(context, mapping, args['width'],
>                           # i18n: "pad" is a keyword
>                           _("pad() expects an integer width"))
>   
> -    text = evalstring(context, mapping, args[0])
> +    text = evalstring(context, mapping, args['text'])
>   
>       left = False
>       fillchar = ' '
> -    if len(args) > 2:
> -        fillchar = evalstring(context, mapping, args[2])
> +    if 'fillchar' in args:
> +        fillchar = evalstring(context, mapping, args['fillchar'])
>           if len(color.stripeffects(fillchar)) != 1:
>               # i18n: "pad" is a keyword
>               raise error.ParseError(_("pad() expects a single fill character"))
> -    if len(args) > 3:
> -        left = evalboolean(context, mapping, args[3])
> +    if 'left' in args:
> +        left = evalboolean(context, mapping, args['left'])
>   
>       fillwidth = width - encoding.colwidth(color.stripeffects(text))
>       if fillwidth <= 0:
> diff --git a/tests/test-command-template.t b/tests/test-command-template.t
> --- a/tests/test-command-template.t
> +++ b/tests/test-command-template.t
> @@ -146,6 +146,9 @@ Keyword arguments:
>     hg: parse error: can't use a key-value pair in this context
>     [255]
>   
> +  $ hg debugtemplate '{pad("foo", width=10, left=true)}\n'
> +         foo
> +

This is super cool!

>   Call function which takes named arguments by filter syntax:
>   
>     $ hg debugtemplate '{" "|separate}'
>