[erlang-questions] dialyzer underspecs warning
Fri Aug 8 13:19:26 CEST 2014
I'm learning how to use -specs + dialyzer and I encountered a problem.
I hope you could help me deal with it.
This is my test function:
test(Array, N, Value) ->
array:set(N, Value, Array).
And this ia a spec I wrote for it:
-spec test(array:array(T), non_neg_integer(), T) -> array:array(T).
When I run dialyzer with -Wunderspecs flag it gives me a warning:
Type specification test:test(array:array(T),non_neg_integer(),T)
-> array:array(T) is a supertype of the success typing: (very long
To my surprise when I change a spec to:
-spec test(array:array(T), non_neg_integer(), _) -> array:array(T).
Dialyzer doesn't give me the warning anymore.
Am I missing something or dialyzer is telling me that T is a supertype
I looked into the source code of array module in stdlib and the -spec
for set function is the same as my original -spec. Running dialyzer with
the same arguments on the array module doesn't give me warnings (at
least for this function).
What should the -spec for my function look like? And should I always run
dialyzer with -Wunderspecs flag, given it is not a default flag?
Thank you in advance,
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