datalark

// Prepare things needed by a starlark interpreter.  (This is Starlark boilerplate!)
thread := &starlark.Thread{
	Name: "thethreadname",
	Print: func(thread *starlark.Thread, msg string) {
		fmt.Printf("%s\n", msg)
	},
}

// Use datalark to make IPLD value constructors available to Starlark!
globals := starlark.StringDict{}
globals["datalark"] = datalark.ObjOfConstructorsForPrimitives()

// Now here's our demo script:
script := testutil.Dedent(`
		print(datalark.String("yo"))
	`)

// Invoke the starlark interpreter!
_, err := starlark.ExecFile(thread, "thefilename.star", script, globals)
if err != nil {
	panic(err)
}

Output:

string{"yo"}

// In this example, we do similar things to the other examples,
// except we put our functions directly into the global namespace.
// You may wish to do this to make it even easier to use
// (but remember to weigh it against cluttering the namespace your users will experience!).

// Prepare things needed by a starlark interpreter.  (This is Starlark boilerplate!)
thread := &starlark.Thread{
	Name: "thethreadname",
	Print: func(thread *starlark.Thread, msg string) {
		fmt.Printf("%s\n", msg)
	},
}

// Use datalark to make IPLD value constructors available to Starlark!
// Note the use of 'InjectGlobals' here -- this puts things into scope without any namespace,
// as opposed to what we did in other examples, which let you choose a name in the globals to put everything under.
globals := starlark.StringDict{}
datalark.InjectGlobals(globals, datalark.ObjOfConstructorsForPrimitives())

// Now here's our demo script:
script := testutil.Dedent(`
		print(String("yo")) # look, no 'datalark.' prefix!
	`)

// Invoke the starlark interpreter!
_, err := starlark.ExecFile(thread, "thefilename.star", script, globals)
if err != nil {
	panic(err)
}

Output:

string{"yo"}

// In this example we'll use an IPLD Schema!
ts := schema.MustTypeSystem(
	schema.SpawnString("String"),
	schema.SpawnStruct("FooBar", []schema.StructField{
		schema.SpawnStructField("foo", "String", false, false),
		schema.SpawnStructField("bar", "String", false, false),
	}, nil),
)
// And we'll bind it to this golang native type:
type FooBar struct{ Foo, Bar string }

// Prepare things needed by a starlark interpreter.  (This is Starlark boilerplate!)
thread := &starlark.Thread{
	Name: "thethreadname",
	Print: func(thread *starlark.Thread, msg string) {
		fmt.Printf("%s\n", msg)
	},
}

// Use datalark to make IPLD value constructors available to Starlark!
globals := starlark.StringDict{}
globals["datalark"] = datalark.ObjOfConstructorsForPrimitives()
globals["mytypes"] = datalark.ObjOfConstructorsForPrototypes(
	bindnode.Prototype((*FooBar)(nil), ts.TypeByName("FooBar")),
)

// Now here's our demo script:
script := testutil.Dedent(`
		print(mytypes.FooBar)
		print(mytypes.FooBar(foo="helloooo", bar="world!"))
	`)

// Invoke the starlark interpreter!
_, err := starlark.ExecFile(thread, "thefilename.star", script, globals)
if err != nil {
	panic(err)
}

Output:

<built-in function datalark.Prototype<FooBar>>
struct<FooBar>{
	foo: string<String>{"helloooo"}
	bar: string<String>{"world!"}
}