Project

General

Profile

Actions
Copy link

Feature #8773

closed

Binding#local_variables should work like #local_variable_set and #local_variable_get

Added by jackdanger (Jack Danger) over 11 years ago. Updated almost 11 years ago.

Status:
Closed
Assignee:
-
Target version:
2.1.0
[ruby-core:56543]

Description

With the addition of Binding#local_variable_get and Binding#local_variable_set the following seemed reasonable:

def get_all_local_variables(bind)
  lvars = bind.send(:local_variables)
  # `lvars` should equal [:x, :y], but equals [:bind, :lvars]
  lvars.map {|name| bind.local_variable_get name }
end
x = 1
y = 2
get_all_local_variables(binding) # NameError: local variable `bind' not defined for #<Binding:0x0>

This is because `local_variables' is global and uses the current stack frame. That was not obvious to me. I could have just used binding.eval("local_variables") but that looked very strange when used alongside binding.local_variable_set and binding.local_variable_get.

Attached is a patch that gives Binding an instance method that properly lists the local variables defined in the binding. It now works like this:

def get_all_local_variables(bind)
  lvars = bind.local_variables
  # `lvars` equals [:x, :y]
  lvars.map {|name| bind.local_variable_get name }
end
x = 1
y = 2
set_everything_but_x_to_5(binding) # => [1, 1]

Here's a GitHub link if you want to see it with colors: https://github.com/JackDanger/ruby/pull/1/files

Files

Download all files
0001-Allowing-binding-to-list-its-local-variables.patch (3.66 KB) 0001-Allowing-binding-to-list-its-local-variables.patch Create Binding#local_variables jackdanger (Jack Danger), 08/11/2013 03:21 PM
0001-Allowing-binding-to-list-its-local-variables.patch (3.66 KB) 0001-Allowing-binding-to-list-its-local-variables.patch Allowing binding to list its local variables [2nd upload] jackdanger (Jack Danger), 08/11/2013 03:52 PM
Actions
Copy link

Also available in: Atom PDF

Like0
Like0Like0Like0Like0