Re: [Chicken-janitors] #759: scrutinizer: extend special case for result-type of "list-ref"/"list-tail" to handle nested "(pair ...)" types

[Chicken Trac]

#759: scrutinizer: extend special case for result-type of "list-ref"/"list-tail"
to handle nested "(pair ...)" types
--------------------------------+-------------------------------------------
  Reporter:  felix              |       Owner:  evhan                         
      Type:  defect             |      Status:  assigned                      
  Priority:  not urgent at all  |   Milestone:                                
 Component:  compiler           |     Version:  4.7.x                         
Resolution:                     |    Keywords:  scrutinizer list-ref list-tail
--------------------------------+-------------------------------------------
Changes (by evhan):

  * owner:  felix => evhan
  * status:  new => assigned


Comment:

 As of 504ec7a30debc416d300157ffb542e660231f08b, nested pair types that
 have an equivalent {{{(list ...)}}} form are handled correctly (since
 they're rewritten as such during simplification).

 What isn't handled are nested pair types that we can't safely rewrite to
 {{{(list ...)}}} type forms. So, I think this ticket now boils down to
 extending the special case s.t. it walks pair type forms as far as
 possible, too. For example, if {{{foo}}} has type {{{(pair fixnum (pair
 fixnum *))}}}, {{{(list-ref foo 1)}}} should resolve to type {{{fixnum}}}
 (even though we don't know for sure whether {{{foo}}} is a proper list).

-- 
Ticket URL: <http://bugs.call-cc.org/ticket/759#comment:1>
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