Run time exeption happening

[Arseny-N]

Hi to everyone, great project! But this code generates a run-time exception:

    hi { a , b } = let
        a = List.map (\x-> x+1) a 
        in b::a 
    hi { a = [1,2], b = 3 }

This is the Repl output:

TypeError: Cannot read property 'ctor' of undefined

Firefox prints in the dev console approximately the following:

TypeError: xs is undefined    ...  index.html:1900:9

I use Linux, elm platform version is 0.17.0, firefox version is 47.0.

[process-bot]

Thanks for the issue! Make sure it satisfies this checklist. My human colleagues will appreciate it!

Here is what to expect next, and if anyone wants to comment, keep these things in mind.

[evancz]

This is a duplicate of #873. Ask on the the Elm Slack or elm-discuss for further clarification if necessary. http://elm-lang.org/community