heredoc for CS?

[jots]

what do you think of adding heredoc to CS? perhaps like ruby's heredoc
http://blog.jayfields.com/2006/12/ruby-multiline-strings-here-doc-or.html
I would find it useful, for instance: setting a variable to a chunk of CS source code.

[jashkenas]

That's kinda why CS supports multiline-strings (take a look at the bottom of the docs). What would you like to do differently with a here-doc? The fancy left-hand-indentation-thing that you can do with Ruby's <<-EOS ?

[jots]

The biggie is removing the need to escape quotes.

[jashkenas]

Ahh. Mind pasting in your use-case here? I think that doing Python-style triple quotes, with left-hand indentation suppressed, would be awfully nice. Combine that with interpolation, and you almost remove the need for JavaScript templates.

[jots]

Oh yeah, add interpolation :-) #{...} syntax?

Use case:
code <<eos
code from http://github.com/creationix/coffeepot/raw/master/lib/lexer.coffee
eos
code from http://github.com/creationix/coffeepot/raw/master/lib/lexer.coffee
CoffeeScript.Lexer.tokenize(code)
I guess the benefit of heredoc vs triple quote is that triplequote would probably appear in the source.

[jashkenas]

Alright Jots -- heredocs are now on master. They're triple-quote (either single or double quotes will do) and keep track of their indentation from the left -- so you can use them from any level of code. This:

html: '''
      <strong>
        cup of coffeescript
      </strong>
      '''

Compiles to:

var html;
html = "<strong>\n  cup of coffeescript\n</strong>";

Closing the ticket...

[weepy]

Here's a bug

bin/coffee -e "html: '''
      <strong>
    cup of coffeescript    
</strong>        
      '''"

gives

  var html;
  html = "<strong>
    cup of coffeescript
</strong>";

[jots]

Thanks for adding this Jeremy! if you ever decide to change it to the normal heredoc syntax, you'll have my vote. I think it's more well known than triple quote (bash, perl, ruby etc.. use "<<") and it allows for triple quote to exist in the string. Still, I do appreciate the triple quote!

[jashkenas]

Thanks for the bug report, weepy -- I've changed the way heredocs work to use smallest left-hand indentation within the heredoc as the indentation level (it used to take the indentation level of the first line).

As for the <<EOS syntax, it's pretty unsightly, no?

[weepy]

re: <<EOS, I don't see any advantage over """