dms

A parser and formatter for angles in degrees, minutes, and seconds.

Parsing

An example of parsing an angle:

	p := dms.NewDefaultParser()
	a, err := p.Parse(`1° 3' 6" S`)
	if err != nil {
		panic(err)
	}
	fmt.Printf("%.6f", a.Degrees())

	// Output:
	// -1.051667

If a parse result is valid, a scan.Angle is returned from the parser that contains the fields that were extracted. The parser uses the following rules:

• Whitespace is not significant
• A real number by itself is valid: 1, -42, 66.123
• Degrees are not bound to a range. A value of 181 degrees is valid.
• Values in either degrees and minutes (DM) format, or degrees, minutes, and seconds format (DMS), must use unit designators that follow each numeric value
• The unit designator for degrees is either a ° or d
• The unit designator for minutes is either a ', ′, or m
• The unit designator for seconds is either a ", ″, or s
• A hemisphere designator of N, S, E, W, may follow the final unit designator of the value
• Minutes must always be followed degrees, seconds must always be followed by minutes
• Degrees must be an integer when minutes are provided and minutes must be an integer when seconds are provided
• Either a numeric sign (+ or -) or a hemisphere designator may appear, but not both

Formatting

A formatter is creating with two parameters, the last unit to show (either DegUnit, MinUnit, or SecUnit), and the number of places for that last unit. For example, to create a degrees and minutes formatter to 3 digits:

	p := dms.NewDefaultParser()
	a, err := p.Parse(`1° 3' 6" S`)
	if err != nil {
		panic(err)
	}
	f := dms.NewFormatter(dms.MinUnit, 3)
	fmt.Println(f.FormatLat(a))

	// Output:
	// 1° 3.100′ S

Status

This package is still a work in progress and is subject to change. If you find this useful, please drop a line at zc at blackchip dot org.

License

MIT