From: dblack@...
Date: 2006-07-29T10:59:36+09:00
Subject: Re: Heredocs and white space

Hi --

On Sat, 29 Jul 2006, dblack@wobblini.net wrote:

> Hi --
>
> On Sat, 29 Jul 2006, Jack Christensen wrote:
>
>> Is there some reason heredocs fail if there is white space after the 
>> closing string? Until I realized what was happening this caused me a good 
>> bit of trouble. Invisible characters shouldn't cause stuff to fail.
>> 
>> Example:
>> s = <<-HEREDOC
>> bla bla bla
>> HEREDOC This fails with:
>> 
>> heredoc.rb:3: can't find string "HEREDOC" anywhere before EOF
>> heredoc.rb:1: parse error, unexpected $, expecting tSTRING_CONTENT or 
>> tSTRING_DB
>> EG or tSTRING_DVAR or tSTRING_END
>> 
>> Delete the spaces at the end of the 3rd line and it works.
>> 
>> I looked through the relevant PickAxe sections and didn't find anything.
>
> The thing is, the mechanism depends on an exact match.  Here's an
> unlikely but possible example of why it might matter.  Line 10 is
> "EOM"; line 12 is "EOM ".
>
> irb(main):008:0> a,b = <<EOM, <<"EOM "
> irb(main):009:0" abc
> irb(main):010:0" EOM
> irb(main):011:0" def
> irb(main):012:0" EOM => ["abc\n", "def\n"]

Actually I don't think I answered your question.  Looking at your
example again, it does look odd.  "HEREDOCabc" would be ignored,
whereas "HEREDOC " causes a failure.  I'm not sure why.


David

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