[erlang-questions] Reassigning variables

Richard O'Keefe <>
Mon Mar 23 03:17:49 CET 2009


On 18 Mar 2009, at 7:07 pm, Matthew Dempsky wrote:
> Also, here's a list of a few other functions in OTP that use numbered
> variables:
>
>  - erl_lint:post_traversal_check/2

This one is

post_traversal_check(Forms, St0) ->
     St1 = check_behaviour(St0),
     St2 = check_deprecated(Forms, St1),
     St3 = check_imports(Forms, St2),
     St4 = check_inlines(Forms, St3),
     St5 = check_undefined_functions(St4),
     St6 = check_unused_functions(Forms, St5),
     St7 = check_bif_clashes(Forms, St6),
     St8 = check_specs_without_function(St7),
     St9 = check_functions_without_spec(Forms, St8),
     StA = check_unused_types(Forms, St9),
     StB = check_untyped_records(Forms, StA),
     check_unused_records(Forms, StB).

which would be easier maintained as

post_traversal_check(Forms, St) ->
     check_unused_records(Forms,
     check_untyped_records(Forms,
     check_unused_types(Forms,
     check_functions_without_spec(Forms,
     check_specs_without_function(
     check_bif_clashes(Forms,
     check_unused_functions(Forms,
     check_undefined_functions(
     check_inlines(Forms,
     check_imports(Forms,
     check_deprecated(Forms,
     check_behaviour(
	St)))))))))))).

It would be even better if all the check_* functions had the
same (Forms, St) -> St' interface, and we could do the
fold-over-function-list trick.






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