は、ここで透析器

Question

で抽象違反が発生し、不透明なタイプを取得できません不透明な型を定義モジュールです：

：

-module(a). 
-export([people/0, get_names/1]). 
-export_type([person/0]). 

-opaque person()  :: {person, first_name()}. 
-type first_name() :: string(). 

-spec people() -> People when 
     People :: [person()]. 

people() -> 
    [{person, "Joe"}, {person, "Cindy"}]. 

-spec get_names(People) -> Names when 
     People  :: [person()], 
     Names  :: [string()]. 

get_names(Ps) -> 
    get_names(Ps, []). 

get_names([ {person, Name} | Ps ], Names) -> 
    get_names(Ps, [Name|Names]); 
get_names([], Names) -> 
    lists:reverse(Names). 

そして、ここではその周りmucks人（）タイプの内部モジュールです私は透析器が文句を言うことが期待

~/erlang_programs$ dialyzer b.erl 
    Checking whether the PLT /Users/7stud/.dialyzer_plt is up-to-date... yes 
    Proceeding with analysis... 
Unknown functions: 
    a:people/0 
done in 0m0.49s 
done (passed successfully) 

：

-module(b). 
-export([do/0]). 

-spec do() -> Name when 
     Name :: string(). 

do() -> 
    [{person, Name} | _People] = a:people(), 
    Name. 

とダイアライザー。

Answer 1

これは動作します：

$ dialyzer a.erl b.erl 

Checking whether the PLT /Users/7stud/.dialyzer_plt is up-to-date... yes 
    Proceeding with analysis... 
b.erl:7: Function do/0 has no local return 
b.erl:8: The attempt to match a term of type a:person() against the pattern 
{'person', Name} breaks the opaqueness of the term 
done in 0m0.52s 
done (warnings were emitted)