From: "mame (Yusuke Endoh)" <mame@...>
Date: 2012-11-24T10:52:09+09:00
Subject: [ruby-core:49959] [ruby-trunk - Feature #7309][Assigned] HEREDOC end of line or similar


Issue #7309 has been updated by mame (Yusuke Endoh).

Status changed from Open to Assigned
Assignee set to matz (Yukihiro Matsumoto)
Target version set to next minor


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Feature #7309: HEREDOC end of line or similar
https://bugs.ruby-lang.org/issues/7309#change-33725

Author: eTM (Juergen Mangler)
Status: Assigned
Priority: Normal
Assignee: matz (Yukihiro Matsumoto)
Category: 
Target version: next minor


example: writing a dsl that expresses some facts

      increase "coding" experience one level until 'next summer'

This can right now be done in different ways

* make the whole thing a string and parse it
* increase.experience('coding').one_level.until('next summer')
* increase "'coding' experience one level until 'next summer'"

Another nice alternative would be a heredoc type that operates to the end of the line (i couldn't find existing implementations for perl and ruby)

      Example1: increase <<* "coding" experience one level until "next summer"
      Example2: increase <<< "coding" experience one level until "next summer"

      def increase(str) # the rest of the line is passed as a string

Although it looks not very elegant for a DSL it would to the job. of course something more unobtrusive would be better, but i don't know how difficult this would be for the parser. e.g.:

      def increase(~str); end

* When a method has ~ attribute it could automatically read the rest of the line as string when invoked (or when used with method call brackets to the closing bracket). Invoke like: 
  
      increase "coding" experience one level until "next summer" 

OR

      increase("coding" experience one level until "next summer")

* ~ attributes always as last attribute: def increase(a,b,~str); end
** Invoke like: increase "val1", "val2", the rest is a string
** In this case the rest str should have a leading " "

------- 

Summary: First possibility (heredoc like) would allow for neat(er) looking dsl's. The second possibility (~attributes, not sure if this is doable) would allow for a VERY neat looking DSL's. Both for sure also would increase the interest in string parsing ;-)


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