Derive Macro QuestionSet 

#[derive(QuestionSet)]
{
    // Attributes available to this derive:
    #[noul]
    #[choice]
    #[score]
    #[question]
    #[question_set]
}

Implements QuestionSet and AnswerSet for a struct with one field per question.

Available with the macros feature, which is on by default.

use typesafe_sdk::{ChoiceAnswer, NoulAnswer, QuestionSet, ScoreAnswer};

#[derive(QuestionSet)]
struct Ticket {
    #[noul(instructions = "Is this about billing?", yes = "payments or invoices")]
    billing: NoulAnswer,
    #[choice(instructions = "What is the tone?", options("calm" = "neutral or polite", "angry"))]
    tone: ChoiceAnswer,
    #[score(instructions = "How urgent?", levels("can wait", "this week", "today"))]
    urgency: ScoreAnswer,
}

assert_eq!(Ticket::prepared().names().collect::<Vec<_>>(), ["billing", "tone", "urgency"]);

Declares a question set as a struct: one field per question, each holding that question’s answer.

The questions are validated and serialized while the program compiles, into the same bytes Questions::prepare produces for them at run time. QuestionSet::prepared hands out that set without allocating, and the generated AnswerSet implementation reads each answer of a response straight into its field.

Attributes

Every field carries exactly one question attribute, and its type is the answer type of that question:

#[noul(instructions = "...", yes = "...", no = "...")]     field: NoulAnswer
#[choice(instructions = "...", options("a" = "...", "b"))] field: ChoiceAnswer
#[score(instructions = "...", levels("low", "high"))]      field: ScoreAnswer

• #[noul]: every key is optional, and #[noul] alone is a noul with nothing set. yes and no describe what counts as each outcome.
• #[choice]: options(...) is required; it lists the options in order, each an option name optionally followed by = "description". An option is listed once. instructions is optional.
• #[score]: levels(...) is required and lists at least one level description, lowest first; a level’s position is its score. instructions is optional.

Each key is given at most once. Every value is a string literal: text is the only content the derive takes. Object or array content is a feature of the runtime Questions builder.

A question is asked under its field’s name, r# removed. Another name, such as one that is not a Rust identifier, is set with #[question(name = "...")] on the field. No two fields answer to one name.

The field type is recognized by its last path segment, so NoulAnswer and typesafe_sdk::NoulAnswer both work; a type alias does not, because a derive sees the tokens of a type and not what they name. A field cannot be an Option: the API answers every question it is asked, and a response without one of the answers is refused as malformed.

The struct itself has named fields, at least one, and no generics. Its name is not one of those the generated code gives to its own items: __QuestionSetField, __QuestionSetFieldVisitor, __QuestionSetVisitor, __D, __M and __private are refused.

Crate path

The generated code reaches the SDK as ::typesafe_sdk. Where it is known by another path, such as a re-export, the container attribute #[question_set(crate = path::to::sdk)] names that path. A dependency renamed in Cargo.toml, as sdk = { package = "typesafe-sdk-rust", ... }, is one such case: the generated code still names ::typesafe_sdk, so the struct needs #[question_set(crate = ::sdk)].

Limits

None on the number of options or levels: the API documents its limits as subject to change, so the server is the one to judge them.