Targets · Go · Example

Example

The whole language in one short program — a module with a record, a tagged union, a function with per-platform native bodies, and a function that wires up state, a write-back and a return — and the complete Go it renders to. It is the same program shown on the language page.

How a Program becomes Go, in parts. Start with the introduction, then follow each part into the rendered output and the runtime it links against.

Introduction — what the Go target is, and how to read the rest of this section.
Capabilities — which high-level features are possible, built in or through a library.
Example — a full program using every keyword, and the Go it renders to.
Naming considerations — how Program's dotted names are carried into Go.
Entry point — starting a program from main with its drivers.
Drivers — the native drivers that provide the interface, console and network.
Runtime — the Reactive and Context machinery the rendered code links against.
Native modules — the hand-written Go behind NATIVE functions.
Keywords — how each of Program's keywords renders to Go.
Project setup — the files and commands to build and run the rendered program.
Reserved words — the words Go keeps for itself, and how a colliding name is escaped.

Every keyword, in one program

Each keyword has its own page under keywords; here they are all together.

MODULE App

  TYPE Profile
    FIELD Text name
    FIELD Maths.Integer age

  TYPE Status
    OPTION App.Profile active
    OPTION Text pending

  FUNCTION Text Greet
    INPUT Text name
    NATIVE js    "return 'Hi ' + name;"
    NATIVE dart  "return 'Hi ' + name;"
    NATIVE go    "return \"Hi \" + name"

  FUNCTION Text Welcome
    INPUT BINDING App.Profile profile
    HOLE Text row
      INPUT Text line
    STATE Maths.Integer count = 0
    STATE LOCKED Network.Web.Response saved = null
    REVERSE App.Profile submit
      LET Network.Web.Response response = Network.Web.Client.Post profile
      SET saved = response
    LET Text label = Maths.Integer.ToString count
    = label

(The function's swift row is replaced with a go one here, since Go needs its own NATIVE body.)

Rendered Go

The module is a package; the record and union are structs named by the underscore join; the functions are methods on a zero-field “static” struct; state uses generics; the function's go body is spliced in; and the trailing = becomes a return.

package app

type App_ProfileData struct {
    name string
    age  int64
}

type App_StatusData struct {
    tag     string
    active  *App_ProfileData
    pending *string
}

type AppStatic struct{}
var App = AppStatic{}

func (AppStatic) Greet(name string) string {
    return "Hi " + name                  // the go NATIVE body
}

func (AppStatic) Welcome(profile *App_ProfileData, row func(line string) ReactiveValue[string]) ReactiveValue[string] {
    count := Program._Runtime.Reactive.State[int64](0)
    saved := Program._Runtime.Reactive.StateLocked[*Network_Web_Response](nil)
    Program._Runtime.Reactive.Reverse(submit, func() {
        response := Network_Web_Client.Post(profile)
        Program._Runtime.Reactive.Set(saved, response)    // SET
    })
    label := Maths_Integer.ToString(count)
    return label
}

Reading it

Indentation becomes nested closures — the REVERSE body is a func() { … }. Dotted names are joined with an underscore, keeping the final access a real dot (Maths_Integer.ToString) — see naming considerations. The per-keyword mapping is on keywords.

Example

Contents

Every keyword, in one program

Rendered Go

Reading it