Review Binding methods

- Fix Binding#[] and #[]= to use local_variable_get/local_variable_set
  (broken since Ruby 1.9; now works again)
- Deprecate Binding#self (use Binding#receiver, Ruby 2.6+)

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: trans

HISTORY.md

@@ -103,6 +103,9 @@ Changes:
   * Redefine `String#lchomp` / `#lchomp!` as aliases for `delete_prefix` / `delete_prefix!`.
   * Rename `Time#trunc` to `Time#floor_to` (parallels `Time#round_to`; avoids confusion
     with Ruby's `Time#floor` which takes sub-second digit precision). `trunc` deprecated.
+  * Fix `Binding#[]` and `#[]=` to use `local_variable_get`/`local_variable_set`
+    (broken since Ruby 1.9; now works again).
+  * Deprecate `Binding#self` (use `Binding#receiver`, adopted by Ruby in 2.6).
   * Deprecate `File.null` (use `File::NULL` constant, Ruby 1.9.3+).
   * Deprecate `File.read_binary` (use `File.binread`, Ruby 1.9.3+).
   * Fix dead requires for removed `kernel/singleton_class` in Proc and Kernel.

lib/core/facets/binding/op_get.rb

@@ -1,25 +1,21 @@
 class Binding
 
-  # Returns the value of some variable.
+  # Returns the value of a local variable.
   #
   #   a = 2
-  #   binding["a"]  #=> 2
+  #   binding[:a]  #=> 2
   #
-  def []( x )
-    eval( x.to_s )
+  def [](name)
+    local_variable_get(name.to_sym)
   end
 
   # Set the value of a local variable.
   #
-  #   binding["a"] = 4
+  #   binding[:a] = 4
   #   a  #=> 4
   #
-  # @deprecated No longer wortks in Ruby 1.9+.
-  #
-  # @see Binding#with for an alternative.
-  def []=( l, v )
-    eval( "lambda {|v| #{l} = v}").call( v )
+  def []=(name, value)
+    local_variable_set(name.to_sym, value)
   end
 
 end
-

lib/core/facets/binding/self.rb

@@ -1,15 +1,9 @@
 class Binding
 
-  # This is already defined by Rubinius:
-  #   Kernel.eval('Rubinius::VariableScope.current.self', self)
-  unless method_defined?(:self)
-
-    # Returns self of the binding's context.
-    def self
-      eval('self')
-    end
-
+  # @deprecated Use Binding#receiver instead (built-in since Ruby 2.6).
+  def self
+    warn "Binding#self is deprecated. Use Binding#receiver instead.", uplevel: 1
+    receiver
   end
 
 end
-