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Comment by wmt | Hacker News Reader

My biggest issue with most garbage collection implementations is the lack of RAII. While I love the ease of reading and writing Python or Lua, I'd love to be able to create a local object, like an open file or a database connection, and have it destructed immediately on return.

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I'm not sure about Lua, but for Python it sounds like you may be interested in the "with" statement.

You can do this in all modern GC languages.

Either with a using/try with resources/with construct, or by using closures.

    // Pseudo language with FP capabilities
    let withFile filename action = 
        let fd = open filename
        action fd
        close fd

    withFile "config.sys" (fun fd -> write (readlines fd))

Real production code would also take care about proper closing the file in case of errors.

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