====== Symbol names and scope ======

===== Naming conventions =====

  * Local variables are lower case, with words (if any) separated by underscores.
  * Class instance variables begin with a single underscore.
  * Formal parameters (arguments passed to functions) begin with an Upper case letter, and are otherwise lower case.
  * Do not use "using".  Instead, explicitly specify the scope with every use.
  * Constants are ALL_CAPS.
  * Members of an enum set begin with a lower case letter, but are otherwise ALL CAPS.  That lower case prefix is the same for all members of the same enum set.
  * Class names may be either ALL_CAPS or may be Mixed_Case_With_Words_Capitalized, with Words_Separated_By_Underscore, but be consistent.  ALL_CAPS are preferred for base classes, Mixed_Case is preferred for "final" and application classes.
  * Do not use CamelCase.
  * Avoid single letter names.
  * Occasionally, it is ok to insert an un_derscore in a funny place to make it easier to "grep".
  * Flag symbols (both variables and methods) begin with "is_", for example "is_empty".

===== Scope guidelines =====

  * In general, please restrict all names to the narrowest useful scope.
  * Avoid globals.  If you really must make something global, put it in a namespace so its origin is clear.
  * Class instance variables should be private or protected.