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Comment by _yosefk | Hacker News Reader

I did cite it - it's from my parent comment's link: http://roscidus.com/blog/blog/2013/06/09/choosing-a-python-r...

Are you saying that:

* Getenv doesn't return an empty string for a non-existent env var?

* Go JSON parser doesn't return an empty list given an empty string?

That you can handle errors without exceptions needn't have an existence proof... The question is how many errors are silenced. Stats will be hard to come by. But getenv and JSON parsing are pretty basic functionality and in most languages with exceptions they would not silence errors. (say, Python's json.loads barfs and os.getenv returns None which unlike the empty string will almost certainly lead to an exception if the code won't account for None). So it's a good anecdote in the absence of hard data.

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Sorry, I missed the blog post. The Go code in the post is garbage. It doesn't check errors, which all good Go code does. (His plan to "add error handling only if the compiler told [him] to" is a bad idea.) I talk about the Go philosophy of error handling here: https://www.youtube.com/watch?v=dKGmK_Z1Zl0#t=27m10s

json.Unmarshal only returns an error value, so it never "returns an empty list". Instead you provide it with a []byte of the JSON data you want decoded and a pointer to the data structure into which to put the decoded data. If you don't check the error value returned by json.Unmarshal then you don't know if it decoded anything or not. That's why the author is left with an empty list.

In reality you'd add two lines to get the following code, which does not proceed past the failure in json.Unmarshal: http://play.golang.org/p/rYfwncjU2f

An aside: os.Getenv doesn't return an error value because it's a convenience that is mostly used in contexts where you don't care if the variable is set or not (in the shell you usually don't care either, you just test for != ""). If you actually care you can inspect the environment with os.Environ. But in this case it doesn't matter.

And here I thought you were talking about the first example in the blog:

    fmt.Println("Hello, world")

Now what happens when program opens a file and is run without stdout:

    ./program >&-

The file it opens is fd 1 and the program prints to the file instead of printing to the console. An odd case that has caused security holes in the past. In languages that fail on errors if they print anything before opening the file then they don't corrupt the file.

The default and laziest case for errors should never be to just hide them and continue on.

JSON parser does return an error on empty string.

http://play.golang.org/p/DE0soRRRBp

Bam!

If you use a `Decoder` instead you can check for the `io.EOF` error in that case.

http://play.golang.org/p/cbWe9se76d

That post is a piece of garbage. He's clearly angling for a language like Rust or Haskell that has a very complex type system for preventing errors in the code, and no other language would succeed with the way he was writing code (which was completely inane). It's like he jumped in a plane, hit full throttle ahead and complained the plane crashed into the ocean instead of landing him safely in Seattle.

Getenv returns an empty string just like unset env variables act like an empty string on the command line. If it returned an error, people would complain it works differently than they're used to. You can't please everyone.

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