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Ask questionsv3: Can Encode() write 1.0 float as 1.0 (instead of 1)

When printing a float with just a zero after decimal point, the decimal point and the zero is not printed.

func main() {
	m := map[string]interface{}{
		"a": 1.0,
	}
	var buf bytes.Buffer
	enc := goyaml.NewEncoder(&buf)
	if err := enc.Encode(m); err != nil {
		panic(err)
	}
	if err := enc.Close(); err != nil {
		panic(err)
	}
	fmt.Println(string(buf.Bytes()))  // Output: a: 1
        // Expected: a: 1.0
}

I see that internally it does the formatting using strconv.FormatFloat() here. Couldn't figure out a way to do it through strconv.FormatFloat() (convert 1 (float) to "1.0"). If it's possible can it be added to the library?

go-yaml/yaml

Answer questions niemeyer

You can use yaml.Node directly or via a yaml.Marshaller if you want to fine tune the encoded string or just preserve the original string value. In the specific example you're using a map of interface{}, with a plain 1.0, so it's using the default behavior of the library which is to encode into the shortest human representation of the number.

I realize this may sound a bit controversial because 1 and 1.0 are two different types as far as the yaml specification is concerned, but this was a conscious choice made early on, based on the idea that the only reason one would pick yaml is because it's human-friendly to read and write, and having software with diverging behavior for 1 and 1.0 would go against that.

If you have further questions or more details about your use case, happy to continue the conversation here.

useful!

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