A construct to restrict the scope of local variables
We sometimes have local variables that are to be used only to keep track of some temporal states/values during a short routine:
... foo = some_initial_value some_routine_that_uses_foo ...
Currently, the scope of local variables are either a proc, a block,
loop body, a method definition, or a class/module definition, but such routines are sometimes just only a part of them.
In order to improve readability of the code by explicitly indicating the scope of such local variables, and to avoid pollution by the variable, I propose to have some construct to restrict the scope of local variables.
One possibility, without adding a new keyword to the current syntax, is to use the
end construct. The expected behavior would be:
begin foo = "foo" foo # => "foo" end foo # => `nil`, or "Undefined local variable or method error"
foo = "bar" begin foo = "foo" foo # => "foo" end foo # => "bar"
Or, does this break the existing code too much? If so, can a new construct be added to the current syntax?