aqua-playground/aqua/examples/option.aqua

import "@fluencelabs/aqua-lib/builtin.aqua"

service SomeS("test2"):
    getStr: ?string -> ?string
    getStr1: -> ?string
    getStr2: string -> string
    checkU32(u: ?u32)

func checkU32AndU8(a: ?u8):
    SomeS.checkU32(a)

func useOptional(opt: ?string) -> string:
    res <- SomeS.getStr(opt)
    for i <- opt:
        SomeS.getStr2(i)
    <- res!

func returnOptional() -> ?string:
    res <- SomeS.getStr1()
    <- res

func returnNone() -> ?string:
    result: *string
    Op.noop()
    <- result