On Tue, Jul 4, 2017 at 10:15 AM, Daniel Dekany <ddek...@apache.org> wrote:
> Tuesday, July 4, 2017, 7:57:18 AM, Woonsan Ko wrote:
>
>> On Wed, Jun 21, 2017 at 2:30 PM, Daniel Dekany <ddek...@apache.org> wrote:
>>> Friday, June 16, 2017, 8:41:37 PM, Daniel Dekany wrote:
>>>
>>>> A problem in FM2 is that when calling a directive (as a macro), either
>>>> all parameters are positional (`<@message "Hi" 2 />`), or all
>>>> parameters are named (`<@message content="Hi" height=2 />`); you can't
>>>> mix the two (`<@message "Hi" height=2 />`). Also you can't use named
>>>> parameters for functions/methods, only for directives. Worse, core
>>>> directives don't even use named parameters, but some keyword like
>>>> `as`, `using`... their syntax is hard coded into the parser, which is
>>>> not nice, and will be a problem for the custom dialects feature.
>>>>
>>>> I think that with the exception of a few core directives (see them
>>>> later) all directive calls should be like this, if for now (in this
>>>> thread) we ignore loop variables:
>>>>
>>>> <#name posPar1 posPar2 namedPar1Name=namedPar1Value
>>>> namedPar2=namedPar2Value>
>>>
>>> An adjustment to the above... I think that we should require comma
>>> between positional arguments (but not between positional and named
>>> arguments and between named arguments):
>>
>> "but not between ..." means that a comma can be *optionally* placed
>> between named arguments or between a positioned argument and a named
>> argument, right?
>
> I wouldn't allow that. If we do, then where to put comma becomes a
> matter of taste, and the taste of individuals in the same project
> differ, or for OS projects, whoever bumps into the templates might has
> a different taste. So overall, you just end up with chaos, and if some
> cares much, it's just unnecessary struggle (which of the 3
> combinations is the Right Way). So I believe it's better overall if we
> decide what's the right way for everyone... Especially as our taste is
> based on more knowledge. FTL tags have this HTML-ish look-and-feel, so
> naturally you write `<#foo n1=v1 n2=v2 m3=v3>`, and not
> `<#foo n1=v1, n2=v2, m3=v3>`. So now, if we add a single positional
> parameter, I think most will find it consistent like this:
> `<#foo v0 n1=v1 n2=v2 m3=v3>` (like in `<@message "Hi" height=2 />`).
> Still no comas anywhere. In the hopefully rare case when you have
> multiple positional parameters, we unfortunately ran into ambiguity
> issues, so then, and only then, and only between the positional
> parameters you add commas. I think that's also matches common
> conventions, where if you list something, you put commas *between* the
> listed items, but not after the last one. Named parameters aren't
> really listed (their order doesn't mater). So it's more logical to
> only use comma where you must, not just a matter of taste.
I concur with you now! Indeed, listing (positional args) requires
comma delimiter, but non-listing (named args) doesn't.
>
> BTW, I was never a fan of this HTML-ish look-and-feel, because of the
> confusing differences; people keep writing `foo="${x}"` instead of
> `foo=x`. But that's the FM tradition, so I try to remain consistent
> with the original idea. (When we manage to separate the expression
> syntax from the top-level syntax, I think I will try to introduce an
> officially supported alternative, something like `#foo(v0, n1=v1,
> n2=v2, m3=v3)`.)
That sounds great, too!
Thanks again for the thorough thoughts and clarifications!
Cheers,
Woonsan
>
>> In other words, it is allowed to omit a comma between positional arg
>> and named arg or between named args.
>>
>> Woonsan
>>
>>>
>>> <#name posPar1, posPar2 namedPar1Name=namedPar1Value
>>> namedPar2=namedPar2Value>
>>
>
> --
> Thanks,
> Daniel Dekany
>
