Functions

Functions run inline during expression evaluation. They do not create state nodes.

Register a function with runtime.MakeFunc:

func join(sep string, values ...string) (string, error) {
    return strings.Join(values, sep), nil
}

func Library() *runtime.Library {
    return &runtime.Library{
        Name: "text",
        Functions: map[string]runtime.FunctionType{
            "join": runtime.MakeFunc("join", "Join strings.", join),
        },
    }
}

Factory source calls it through the import alias:

text.join(',', input.first, input.second)

Function parameters and return values can use bool, int64, float64, string, any, slices, and string-keyed maps of those types. The function must return (value, error).

During compile, Unobin reads the selected Go libraries and checks function existence, argument count, and argument types at call sites.