Hamlet: no space is inserted between multiple lines of text about shakespeare

[jameshfisher]

Any opinions on this? I can have a go at fixing this myself, if time is the issue. I just really hope it's not by design.

[snoyberg]

I thought I'd responded to this, but apparently it didn't make it through.

There's a discussion on the Yesod mailing list about this right now. This approach is by design. If you want a workaround for now, you can turn on newline appending.

This approach may be changed in the future, but it's not clear yet that we'll actually do so.

[jameshfisher]

Does closing this issue signal that this behavior is not going to be changed? Could you point me to the mailing list discussion? What do you mean by "turn on newline appending"? This is pretty much a deal-breaking bug in Hamlet for me, BTW.

[jameshfisher]

There are other serious issues with Hamlet not respecting HTML whitespace semantics, too. For instance:

• [|hamlet|<span>foo|] gives me <span>foo</span>, but [|hamlet|<span>#{foo}|] gives me <span>\nfoovalue\n</span>
• mconcat inserts newlines between elements

Both of which are unacceptable. Are these going to be changed? Is there any documented justification for the current behavior?

[snoyberg]

Closing indicates that a bug report is not the right place for this discussion. There have been a few threads about this recently, eg:

https://groups.google.com/d/topic/yesodweb/-nTfT9SZsWQ/discussion

As far as turning on newlines, please have a look at the Haddocks:

http://hackage.haskell.org/packages/archive/hamlet/1.0.1.4/doc/html/Text-Hamlet.html#v:hamletNewlines

Simply referring to this as a bug isn't going to make it true; there are valid reasons for both behaviors, and insisting that your way is the only correct way is not really going to motivate any change. A healthy discussion on the mailing list, however, will.

As far as your other cases, if they are true, they are bugs. I'd like to see a reproducing test case, as I have seen no such behavior. (If the mconcat case is true, it's coming from blaze-html, not hamlet, so the bug report would need to be filed there.)

[jameshfisher]

Apologies: that behavior is Blaze.

hamletNewlines seems an OK workaround for now.

I suspect the current behavior is because where multiple lines represent multiple tags, you want to concatenate them all without any space in between.

Could we not have an exception to this for two adjacent lines of text, in which case a space is inserted?

[jameshfisher]

Unfortunately hamletNewlines seems to be inserting newlines where I don't want them. Specifically, if I do

[hamlet|
  One ^{two}.
|]

I get the output

One 
two
.

Is this desired behaviour? What can I do to work around this?

[snoyberg]

I don't believe this is coming from Hamlet, but from your definition of two (you had a similar example above I believe). For future bug reports, can you include full test programs so we can avoid false reports?

I'm not going to make any decisions about changes to Hamlet based on a discussion in this issue. If you would like to propose changes, please do so on the mailing list.