Add .rb extension to tempfile in vi mode

[DylanGriffith]

Problem

When you are in VI mode and you enter normal mode and press v it opens up your $EDITOR to edit the current context. The issue is that your $EDITOR does not know that you are editing Ruby code so you don't get any syntax highlighting or formatting.

Solution

This change adds a .rb extension to the tempfile opened by the editor which then ensures you get the correct syntax highlighting and formatting.

Demo

See the following demo to see how this changes things:

vim-mode-edit-with-syntax.mp4

[DylanGriffith]

I couldn't find an obvious test to change for this. I'm happy to make such a change if necessary.

Also I wasn't sure about whether to add the reline to the file or some other static string. It seems that Tempfile requires me to put some file name in there if I want to add an extension.

[tompng]

Reline is a general purpose readline library compatible with GNU Readline. Input to Reline and Readline is not always a ruby code.

require 'json'
require 'readline' # loads 'reline' in Ruby >= 3.3 if readline-ext is not installed
p Readline == Reline #=> true

# Simple JSON colorization
Reline.output_modifier_proc=proc{|code|
  code.gsub(/("[^"]*")|(\d+(?:\.\d+)?)|(null|true|false)/){
    color = $1 ? 31 : $2 ? 34 : 36
    "\e[#{color}m#{$&}\e[0m"
  }
}

loop do
  puts "Enter JSON configuration"
  json = Readline.readline('> ', true) # input is JSON, not a ruby code
  puts JSON.parse(json)
end

This is why IRB's syntax highlighting logic is placed in IRB, not in Reline.

vi_histedit doesn't seem to exist in GNU Readline, so I don't want to add a new environment variable or an API to customize the file extension only for this feature.

[elfham]

FYI, vi_histedit probably comes from Editline.

Reline is mainly based on GNU Readline, but also takes a lot from Editline.