#1762: Maybe/Just Int checker in Silex compilation

[Chicken Trac]

#1762: Maybe/Just Int checker in Silex compilation
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            Reporter:  Idiomdrottning  |       Type:  enhancement
              Status:  new             |   Priority:  not urgent at all
           Milestone:  someday         |  Component:  unknown
             Version:  5.2.0           |   Keywords:
Estimated difficulty:                  |
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 When chicken-install silex I get this

 Warning: Invalid argument
   In file `silex.scm:472',
   In module `silex',
   In procedure `digraph',
   In procedure `store-final338',
   In procedure `loop',
   In procedure call:

     (scheme#vector-set! prio voisin infinity)

   Argument #2 to procedure `vector-set!' has an invalid type:

     false

   The expected type is:

     fixnum

   This is the expression:

     voisin

   Procedure `vector-set!' from module `scheme' has this type:

     (vector fixnum * -> undefined)

 In the code, the index value "voisin" is derived from a vector-ref call on
 another vector that's initialized with #f's but populated by fixnums
 (hopefully? I didn't fully analyze the code here…) before being
 referenced.

 So probably one of two things are going on:

 The silex code is bugged and the variable won't be a fixnum in time (in
 which case this is is a serious bug in silex), or (what I believe is more
 likely)

 The type-checking code is mislabeling the situation here. It doesn't know
 that it'll be an int in time. This is just an, uh, "cosmetic" bug in core,
 which is how I'm labeling it. Or I'm wrong and it's instead a serious bug
 in exts (silex).

-- 
Ticket URL: <https://bugs.call-cc.org/ticket/1762>
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