Feature #5352: How about using <> to represent Here Document?

• Status: Rejected
• Assignee: matz (Yukihiro Matsumoto)
• Target version: 3.0

[yimutang (Joey Zhou)]

"<<" is a frequently used method in text manipulation. Meanwhile, it's also the beginning token of a here-document.
Sometimes it may be confusing to newbies.

Unlike Perl, in which "<>" is a very very frequently used operator to read lines from a filehandle, in Ruby, "<>" has no meaning. So I think it can be used to represent Here Document, so as to reduce the possibility of misunderstanding method "<<" and here-document token "<<". And In my opinion, <> is more clear than <<, because it looks like kind of brackets.

For example,

  str = <SECT1>.upcase + <SECT2>.downcase
  aaaaaa
  SECT1
  XXXXXX
  SECT2

may be clearer than:

  str = <<SECT1.upcase + <<SECT2.downcase

[duerst (Martin Dürst)]

If anything is done in this direction, I'd prefer

   str = <>SECT1.upcase + <>SECT2.downcase

over

   str = <SECT1>.upcase + <SECT2>.downcase

It seems to stick out much better.

[yeban (Anurag Priyam)]

On Fri, Sep 23, 2011 at 7:08 AM, Martin Dürst [e-mail] wrote:
[...]

If anything is done in this direction, I'd prefer
  str

[nobu (Nobuyoshi Nakada)]

Joey Zhou wrote:

Unlike Perl, in which "<>" is a very very frequently used operator to read lines from a filehandle, in Ruby, "<>" has no meaning. So I think it can be used to represent Here Document, so as to reduce the possibility of misunderstanding method "<<" and here-document token "<<". And In my opinion, <> is more clear than <<, because it looks like kind of brackets.

I'm somewhat negative.
It looks like Perl's "<>" but is pretty different, so I'm afraid that it would be also confusing.

[yimutang (Joey Zhou)]

Nobuyoshi Nakada wrote:

I'm somewhat negative.
It looks like Perl's "<>" but is pretty different, so I'm afraid that it would be also confusing.

There are a few things different in Ruby and Perl.

$foo is not a scalar, @bar is not an array, %w is not a hash

"re = /pattern/" in Ruby means assigning a regexp to re, but in Perl "$re = /pattern/" means "$re = $_ =~ /pattern/"...

So I think the difference is not a problem, some differences already exist.

"<<" of Perl has two meanings: shifting bits and here document. One is for the integers and the other is for the string, maybe leading to less confusing. However, in Ruby, "<<" is instance method of String and IO/File, and here document is also string, the probability of confusing is larger, I'm afraid.

[mame (Yusuke Endoh)]

• Status changed from Open to Assigned
• Assignee set to matz (Yukihiro Matsumoto)

[mame (Yusuke Endoh)]

• Target version set to 3.0

[naruse (Yui NARUSE)]

• Description updated (diff)

[matz (Yukihiro Matsumoto)]

• Status changed from Assigned to Rejected

Rejected. I don't want to change the basic syntax (without major benefit). Besides that, I want to keep <> for future syntax extension.

Matz.