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Feature #19015

open

Language extension by a heredoc

Added by ko1 (Koichi Sasada) over 2 years ago. Updated over 1 year ago.

Status:
Open
Assignee:
-
Target version:
-
[ruby-core:109985]

Description

This propose new heredoc extension with <<!LANG like

doc = <<!LANG
  # description written in lang LANG
  foo bar
LANG

and it is translated to:

doc = heredoc_extension_LANG(heredoc_text, binding)

Example

require 'erb'

def heredoc_extension_erb str, b
  ERB.new(str).run(b)
end

name = 'ko1'

html = <<!erb
<div>Hello <%= name %></div>
erb

puts html #=> <div>Hello ko1</div>

Background / considerations

  • Sometimes we write Ruby syntax string with <<RUBY and this proposal inspired by it.
  • it is similar to shebang (#!LANG in shell)
  • Elixir's custom sigil translates ~u(...) translates to sigil_u(...). This is why it translated to heredoc_extension_LANG(...) private method call.
  • JavaScript has JSX but I don't think it is fit to the Ruby language.
  • Heredoc is Ruby's chaos part and already confusing a lot. Additional chaos doesn't matter.
  • <<!foo is valid syntax but now I don't think it is not used. gem codesearch doesn't find the usage.
  • Sorry I couldn't wait 1st/Apr.

Implementation

I attached the experimental implementation which only supports erb (because I couldn't find how to get delimiter to determine a method name :p).


Files

heredoc_extension.patch (2.7 KB) heredoc_extension.patch ko1 (Koichi Sasada), 09/22/2022 03:23 AM
#1

Updated by ko1 (Koichi Sasada) over 2 years ago

  • File deleted (tmp.YubJ1EHi0O-xyzzy)
#6

Updated by ko1 (Koichi Sasada) over 2 years ago

  • Description updated (diff)
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