Ruby - print the variable name and then its value

Question

What is the best way to write a function (or something DSLish) that will allow me to write this code in Ruby. How would I construct the function write_pair?

Answer 1

def write_pair var, binding
  puts "#{ var } = #{ eval(var, binding)}"
end


username = "tyndall"
write_pair "username", binding

This seems weird because binding is never defined, but it works. From Ruby: getting variable name:

The binding() method gives a Binding object which remembers the context at the point the method was called. You then pass a binding into eval(), and it evaluates the variable in that context.

Be sure to pass a string, not the variable.

Answer 2

I made a vim macro for this:

" Inspect the variable on the current line (in Ruby)
autocmd FileType ruby nmap ,i ^"oy$Iputs "<esc>A: #{(<esc>"opA).inspect}"<esc>

Put the variable you'd like to inspect on a line by itself, then type ,i (comma then i) in normal mode. It turns this:

foo

into this:

puts "foo: #{(foo).inspect}"

This is nice because it doesn't have any external dependencies (e.g. you don't have to have a library loaded up to use it).