Closure with type may produce compiler error

[felixvf]

Consider this Mirah code:

class Bar
end

interface Foo
    def action(bar:Bar); end
end

class FooCaller

    def with_foo(foo:Foo):void
        foo.action(Bar.new)
    end

    def call_with_foo
        with_foo do |bar:Bar|
            puts "Closure called."
        end
    end
end

FooCaller.new.call_with_foo

it should compile cleanly, but instead the compiler fails with

ERROR: Internal compiler error: java.lang.ClassCastException: org.mirah.jvm.mirrors.MirrorProxy cannot be cast to org.mirah.jvm.mirrors.BaseType org.mirah.jvm.mirrors.MirrorProxy cannot be cast to org.mirah.jvm.mirrors.BaseType. Rerun in verbose mode for stacktrace.
Exception in thread "main" org.mirah.jvm.compiler.ReportedException: java.lang.ClassCastException: org.mirah.jvm.mirrors.MirrorProxy cannot be cast to org.mirah.jvm.mirrors.BaseType
        at org.mirah.jvm.mirrors.SafeTyper.betterException(safe_typer.mirah:72)
        at org.mirah.jvm.mirrors.SafeTyper.betterException(safe_typer.mirah:58)
        at org.mirah.jvm.mirrors.SafeTyper.finish_closures(safe_typer.mirah:55)
        at org.mirah.tool.MirahCompiler.infer(mirah_compiler.mirah:175)
        at org.mirah.tool.MirahTool.compile(mirah_tool.mirah:107)
        at org.mirah.tool.Mirahc.main(mirahc.mirah:34)
        at org.mirah.MirahCommand.compile(mirah_command.mirah:27)
        at org.mirah.MirahCommand.main(mirah_command.mirah:43)
Caused by: java.lang.ClassCastException: org.mirah.jvm.mirrors.MirrorProxy cannot be cast to org.mirah.jvm.mirrors.BaseType
        at org.mirah.typer.BetterClosureBuilder.build_methods_for(better_closures.mirah:1028)
        at org.mirah.typer.BetterClosureBuilder.build_and_inject_methods(better_closures.mirah:1100)
        at org.mirah.typer.BetterClosureBuilder.finish(better_closures.mirah:504)
        at org.mirah.typer.Typer.finish_closures(typer.mirah:75)
        at org.mirah.jvm.mirrors.SafeTyper.finish_closures(safe_typer.mirah:53)
        ... 5 more

Note that the related code

class Bar
end

interface Foo
    def action(bar:Bar); end
end

class FooCaller

    def with_foo(foo:Foo):void
        foo.action(Bar.new)
    end

    def call_with_foo
        with_foo do |bar|
            puts "Closure called."
        end
    end
end

FooCaller.new.call_with_foo

compiles and runs fine.

[felixvf]

Fixed by #378.