{"action":"created","issue":{"url":"https://api.github.com/repos/JuliaLang/julia/issues/10307","labels_url":"https://api.github.com/repos/JuliaLang/julia/issues/10307/labels{/name}","comments_url":"https://api.github.com/repos/JuliaLang/julia/issues/10307/comments","events_url":"https://api.github.com/repos/JuliaLang/julia/issues/10307/events","html_url":"https://github.com/JuliaLang/julia/issues/10307","id":58737031,"number":10307,"title":"Mapping empty Arrays","user":{"login":"MillCheck","id":8100272,"avatar_url":"https://avatars.githubusercontent.com/u/8100272?v=3","gravatar_id":"","url":"https://api.github.com/users/MillCheck","html_url":"https://github.com/MillCheck","followers_url":"https://api.github.com/users/MillCheck/followers","following_url":"https://api.github.com/users/MillCheck/following{/other_user}","gists_url":"https://api.github.com/users/MillCheck/gists{/gist_id}","starred_url":"https://api.github.com/users/MillCheck/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/MillCheck/subscriptions","organizations_url":"https://api.github.com/users/MillCheck/orgs","repos_url":"https://api.github.com/users/MillCheck/repos","events_url":"https://api.github.com/users/MillCheck/events{/privacy}","received_events_url":"https://api.github.com/users/MillCheck/received_events","type":"User","site_admin":false},"labels":[],"state":"open","locked":false,"assignee":null,"milestone":null,"comments":3,"created_at":"2015-02-24T13:20:50Z","updated_at":"2015-02-24T18:52:19Z","closed_at":null,"body":"typeof(float(String[])) is Array{String,1}. This can cause performance issues.\r\ntypeof(map(float, String[])) behaves the same.\r\n\r\nEven worse, runtime errors if someone reads numbers from a line and later tries to push! something to them - if the line was empty, you get an ERROR."},"comment":{"url":"https://api.github.com/repos/JuliaLang/julia/issues/comments/75820179","html_url":"https://github.com/JuliaLang/julia/issues/10307#issuecomment-75820179","issue_url":"https://api.github.com/repos/JuliaLang/julia/issues/10307","id":75820179,"user":{"login":"JeffBezanson","id":744556,"avatar_url":"https://avatars.githubusercontent.com/u/744556?v=3","gravatar_id":"","url":"https://api.github.com/users/JeffBezanson","html_url":"https://github.com/JeffBezanson","followers_url":"https://api.github.com/users/JeffBezanson/followers","following_url":"https://api.github.com/users/JeffBezanson/following{/other_user}","gists_url":"https://api.github.com/users/JeffBezanson/gists{/gist_id}","starred_url":"https://api.github.com/users/JeffBezanson/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/JeffBezanson/subscriptions","organizations_url":"https://api.github.com/users/JeffBezanson/orgs","repos_url":"https://api.github.com/users/JeffBezanson/repos","events_url":"https://api.github.com/users/JeffBezanson/events{/privacy}","received_events_url":"https://api.github.com/users/JeffBezanson/received_events","type":"User","site_admin":false},"created_at":"2015-02-24T18:52:19Z","updated_at":"2015-02-24T18:52:19Z","body":"For those particular conversion functions, e.g. `float()`, it would be totally reasonable for them to pick the result type and use `map!` instead."}}