This is the ChtoZaSlova Go library, command-line tool, and API server.

It converts between latitude/longitude coordinates and what3words addresses.

ChtoZaSlova is free and open source software published under the Creative Commons CC0 license. Please copy and distribute widely.

    import "chtozaslova/chtozaslova"

    ...

    words, err := chtozaslova.LatLon2Words(37.234332, -115.806657)
    fmt.Println(words)
    lat, lon, err := chtozaslova.Words2LatLon("joyful.nail.harmonica")
    fmt.Printf("%.6f %.6f\n", lat, lon)

See example/main.go for an example.

LatLon2Words and Words2LatLon are the only functions considered part of the API, but you are welcome to use the other exported functions if you find them useful.

The tool in cmd/chtozaslova/ is a command-line interface for converting between latitude/longitude coordinates and what3words addresses.

Help text is as follows:

usage: chtozaslova [-i] [INPUT...]

Options:
  -i    read from stdin

If not -i, you should specify at least one INPUT in the form lat,lon or words. It is perfectly acceptable to mix lat,lon and word inputs in a single invocation.

Examples:
    chtozaslova -i < words.txt
    chtozaslova joyful.nail.harmonica
    chtozaslova 37.234332,-115.806657

Output is of the form "INPUT[tab]OUTPUT" with one line per INPUT, where OUTPUT will be either the converted INPUT, or an error message.

The tool in cmd/chtozaslovad/ is an HTTP server that provides a HTTP API for converting between latitude/longitude coordinates and what3words addresses. It listens on port 8081.

Parameters are passed in the HTTP query string and responses are formatted as JSON.

Make requests like:

$ curl http://localhost:8081/api/convert-to-coordinates?words=joyful.nail.harmonica
{"words":"joyful.nail.harmonica","language":"en","coordinates":{"lat":37.234328,"lon":-115.806657}}
$ curl http://localhost:8081/api/convert-to-3wa?coordinates=37.234328,-115.806657
{"words":"joyful.nail.harmonica","language":"en","coordinates":{"lat":37.234328,"lon":-115.806657}}

In the event of an error, the error key will exist in the returned JSON hash, and the value of this key will be an error message:

$ curl http://localhost:8081/api/convert-to-coordinates?words=errormessage
{"error":"Error decoding words"}

The files of the library are in *.go in the root directory.

For the command line application, see cmd/chtozaslova/main.go.

For the API server, see cmd/chtozaslovad/main.go.