I would like to be clear on the design goal of being closer to html. All other things being equal, it is simply about avoiding a larger mental overhead when switching between html and hamlet. The new syntax does not mean we are "writing html" or have any "constraints" not already present in hamlet. It simply means attributes use a space instead of a '!', and tags begin with a '<' instead of a '%', and are separated with their inner text by a '>' instead of a space. While the proposal discusses the possibility of allowing things like closing tags, that would be optional if it were implemented.

Reducing the mental "context switch" could be useful for existing hamlet users that also works with html in other projects. But it is largely about getting more users of hamlet, particularly when they start a new project. I would not expect many projects to switch a project over, and closeness to html when switching an existing project over doesn't matter much once converters are available, and the larger the project, the more practical it is to write a converter. I see the real practical use on a smaller scale- if you want to copy and paste some html into your file, including html from a more traditional templating language where a converter may not available.

Space-based attributes:

Are there any objection to the *concept* of the change to use a space with attributes instead of a '!'?. This would actually make hamlet *more* similar to HAML.

The difficulty in implementation is with determining the end of the attribute portion of the tag. For '%body id=the-body' there would be ambiguity as to whether the id started an attribute or inner text. Even worse is an attribute without a value 'input type=checkbox checked'. One technique is to assume it is an attribute if an '=' sign is present- requiring escaping the '=' sign, and requiring a (possibly empty) value for every attribute. HAML handles attributes by requiring opening and closing symbole: '(attribute=name attribute2=name)', which looks nice, but I would much rather have white space to begin attributes, and the closing character is forced on you when there is no inner text.

Following my original proposal, the attributes could have a closing character that is optional when there is no text.

%body id=the-body class=the-class>Inner Text

I could appreciate that this might look peculiar to someone when the tag leads with a '%' instead of a '<' as in the original proposal. I think '&' could be a lot more appealing and signifies 'and there is text', also similar to how it signifies more parameters in a url.

%body id=the-body class=the-class&Inner Text

So I am still proposing the original proposal. If the original is not accepted, or if we want more time to think about it or otherwise an intermediate step is desired I would still propose using a space-based attribute syntax. We could also consider the possibility of allowing both the '%&' and the '<>' syntaxes now that they would be very similar. However, I would strongly argue for using the html-compatible syntax. Those whose senses are offended by a lone opening '<' can still add the '>' and justify that it prepares them for adding inner text.

On Sun, Dec 12, 2010 at 3:00 AM, <web-devel-request@haskell.org> wrote:

Send web-devel mailing list submissions to
web-devel@haskell.org

To subscribe or unsubscribe via the World Wide Web, visit
http://www.haskell.org/mailman/listinfo/web-devel
or, via email, send a message with subject or body 'help' to
web-devel-request@haskell.org

You can reach the person managing the list at
web-devel-owner@haskell.org

When replying, please edit your Subject line so it is more specific
than "Re: Contents of web-devel digest..."

Today's Topics:

1. Re: proposal for hamlet-like syntax that is more compatible
with html (Michael Snoyman)
2. Re: proposal for hamlet-like syntax that is more compatible
with html (Alexandros Salazar)
3. Re: proposal for hamlet-like syntax that is more compatible
with html (Alexander Dunlap)

----------------------------------------------------------------------

Message: 1
Date: Sat, 11 Dec 2010 17:48:48 +0200
From: Michael Snoyman <michael@snoyman.com>
Subject: Re: [web-devel] proposal for hamlet-like syntax that is more
compatible with html
To: Simon Michael <simon@joyful.com>
Cc: web-devel@haskell.org
Message-ID:
<AANLkTinumxoNV-efehgrVBUnoNUYvRB1ijC01aN6Pv=6@mail.gmail.com>
Content-Type: text/plain; charset=ISO-8859-1

Alright, at this point I've only heard positive things about this
syntax change. Does anyone want to volunteer to try and tackle this,
or will this need to wait till I can get around to it? Fair warning:
I'm likely to try to deal with the WAI + enumerator and xml-enumerator
tasks first. If someone wants to take a crack at the Hamlet changes,
I'll be happy to review things.

Michael

On Sat, Dec 11, 2010 at 2:38 AM, Simon Michael <simon@joyful.com> wrote:
> I support this proposal's goal, and would be fine with rewriting my
> templates.
>
>
> _______________________________________________
> web-devel mailing list
> web-devel@haskell.org
> http://www.haskell.org/mailman/listinfo/web-devel
>

------------------------------

Message: 2
Date: Sat, 11 Dec 2010 11:17:37 -0500
From: Alexandros Salazar <nomothetis@gmail.com>
Subject: Re: [web-devel] proposal for hamlet-like syntax that is more
compatible with html
To: web-devel@haskell.org
Message-ID:
<AANLkTikxJfPFOnD8Fzo9-bpH9g8Z6S6n8aCwB9+kvbAM@mail.gmail.com>
Content-Type: text/plain; charset="utf-8"

My belated 2c (sorry, work has been keeping me away from things Yesod and
Haskell):

1. The key reason I switched to Yesod was Hamlet. I'm very new to Haskell,
and I wanted to try developing a webapp in it; when I looked at the various
frameworks, my main question was "What will require me to learn the least
new stuff, while still giving me a full Haskell-based development
experience?" Yesod was the answer, because I was already familiar with Haml.
So, it is one less thing a large swath of people need to learn when they
decide to give Yesod a try. And at least in my case, it was a deciding
factor.

2. I'm not convinced closeness to HTML is a design goal. My experience is
again limited, but I wouldn't expect many people to switch existing projects
to Yesod (or really, from any framework to any other); therefore, the idea
that someone will have a bunch of HTML to be converted as simply as possible
to whatever templating language we use seems remote.

3. Along the same lines, the reason for the existence of templating
frameworks like Haml and Hamlet is precisely that people don't enjoy writing
HTML: why would we constrain ourselves by similarity to something people
have put large (and creative) amounts of effort into avoiding? I think it is
unduly limiting.

4. I do believe there are some issues with Hamlet; in fact, the issues
raised by Greg are exactly the issues I have. I don't see having a
Yesod-specific templating language as the solution, unless this new syntax
gives Yesod such a big productivity boost compared to using Hamlet that it's
worth putting in the effort.

In brief, I think Hamlet is 95% of the way there, and that Michael has done
a great job with it. It seems easier to take it another 4% and get it to 99%
than it would be to rewrite the syntax from scratch. I don't view HTML
similarity as a bonus (or a malus, either way). Maintaining (and furthering)
similarity with Haml seems worthier goal, given how many people use it, are
familiar with it, and love it; it will ease adoption.

I hope this all made sense, and that I didn't start an argument about bike
shed colors... ;-)

Alexandros

On Sat, Dec 11, 2010 at 10:48 AM, Michael Snoyman <michael@snoyman.com>wrote:

> Alright, at this point I've only heard positive things about this
> syntax change. Does anyone want to volunteer to try and tackle this,
> or will this need to wait till I can get around to it? Fair warning:
> I'm likely to try to deal with the WAI + enumerator and xml-enumerator
> tasks first. If someone wants to take a crack at the Hamlet changes,
> I'll be happy to review things.
>
> Michael
>
> On Sat, Dec 11, 2010 at 2:38 AM, Simon Michael <simon@joyful.com> wrote:
> > I support this proposal's goal, and would be fine with rewriting my
> > templates.
> >
> >
> > _______________________________________________
> > web-devel mailing list
> > web-devel@haskell.org
> > http://www.haskell.org/mailman/listinfo/web-devel
> >
>
> _______________________________________________
> web-devel mailing list
> web-devel@haskell.org
> http://www.haskell.org/mailman/listinfo/web-devel
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://www.haskell.org/pipermail/web-devel/attachments/20101211/1d41e534/attachment-0001.htm>

------------------------------

Message: 3
Date: Sat, 11 Dec 2010 18:32:51 -0800
From: Alexander Dunlap <alexander.dunlap@gmail.com>
Subject: Re: [web-devel] proposal for hamlet-like syntax that is more
compatible with html
To: Michael Snoyman <michael@snoyman.com>
Cc: Simon Michael <simon@joyful.com>, web-devel@haskell.org
Message-ID:
<AANLkTinqnFVeCyOHLudnxpKGXWXFGmsHrFVX=6eBTivr@mail.gmail.com>
Content-Type: text/plain; charset=UTF-8

I would prefer that the bikeshed stay the color it already is. ;) The
syntax is easier for me as it is different from HTML. The HTML-like
syntax looks to me like invalid HTML and is more difficult to read.

Alex

On Sat, Dec 11, 2010 at 7:48 AM, Michael Snoyman <michael@snoyman.com> wrote:
> Alright, at this point I've only heard positive things about this
> syntax change. Does anyone want to volunteer to try and tackle this,
> or will this need to wait till I can get around to it? Fair warning:
> I'm likely to try to deal with the WAI + enumerator and xml-enumerator
> tasks first. If someone wants to take a crack at the Hamlet changes,
> I'll be happy to review things.
>
> Michael
>
> On Sat, Dec 11, 2010 at 2:38 AM, Simon Michael <simon@joyful.com> wrote:
>> I support this proposal's goal, and would be fine with rewriting my
>> templates.
>>
>>
>> _______________________________________________
>> web-devel mailing list
>> web-devel@haskell.org
>> http://www.haskell.org/mailman/listinfo/web-devel
>>
>
> _______________________________________________
> web-devel mailing list
> web-devel@haskell.org
> http://www.haskell.org/mailman/listinfo/web-devel
>

------------------------------

_______________________________________________
web-devel mailing list
web-devel@haskell.org
http://www.haskell.org/mailman/listinfo/web-devel

End of web-devel Digest, Vol 16, Issue 6
****************************************