Generics

typewriter supports generic type parameters.

Basic Generics

#![allow(unused)]
fn main() {
#[derive(TypeWriter)]
#[sync_to(typescript, python)]
pub struct Pagination<T> {
    pub items: Vec<T>,
    pub total: u64,
    pub page: u32,
    pub page_size: u32,
}
}

TypeScript:

export interface Pagination<T> {
  items: T[];
  total: bigint;
  page: number;
  page_size: number;
}

Python:

from typing import Generic, TypeVar, Optional

T = TypeVar("T")

class Pagination(BaseModel, Generic[T]):
    items: list[T]
    total: int
    page: int
    page_size: int

Multiple Type Parameters

#![allow(unused)]
fn main() {
#[derive(TypeWriter)]
#[sync_to(typescript)]
pub struct Map<K, V> {
    pub keys: Vec<K>,
    pub values: Vec<V>,
}
}

Nested Generics

Generics can contain other generic types:

#![allow(unused)]
fn main() {
#[derive(TypeWriter)]
#[sync_to(typescript)]
pub struct Nested {
    pub users: Vec<Pagination<User>>,
    pub configs: HashMap<String, Vec<Config>>,
}
}

Constraints

Generic constraints (e.g., where T: Clone) are not currently preserved in output.