This Go package provides functions that parse query strings and apply them to a Go struct.

I had very specific needs here. I needed the unmarshal function to copy the values of any unexported fields from a prototype instance but then overwrite exported fields with the values of query variables. In other words, the unmarshal function fuses together unexported fields form the prototype with exported fields from the query string.

The library handles string, int, uint, bool and float types. If a value in a struct is meant to be optional, it should have a pointer type. If it is meant to have multiple values, it should be either a slice (for any arbitrary number of elements) or an array (for a fixed number of elements). Finally, if it is just one of the supported primitives, it is assumed to be required.

Along the way, lots of checking and casting is done to ensure that the resulting struct is validated.

Here is a simple example, consider the following Go code:

type Example1 struct {
	unexportedData bool
	Message        string
	Weight         *int `unq:"weight"`
	Vec            [3]float64
	Names          []string `unq:"names"`
}

...
    v := Example1{
        unexportedData: true,
	}
	sig, err := Scan(v)
	copy1 := Example1{}
	unquery.Unmarshal("Message=Hello&Vec=.1&Vec=.2&Vec=.3&names=bill", sig, &copy1)

After the call to Unmarshal, the value of copy1 will be:

Example1{
	unexportedData: true,
	Message:        "Hello",
	Weight:         nil,
	Vec:            [3]float64{0.1, 0.2, 0.3},
	Names:          []string{"bill"},
}