Crate utility_types

utility types

This crate use proc-macro to realize several utility types of Typescript in Rust.

macro	Typescript Utility Type
Partial	Partial<Type>
Pick	Pick<Type, Keys>
Omit	Omit<Type, Keys>
Extract	Extract<Type, Union>
Exclude	Exclude<UnionType, ExcludedMembers>

Example

Here is an example of how to use this crate.

use utility_types::{Omit, Partial, Pick, Required};
#[derive(Clone, Partial, Required, Pick, Omit)]
#[partial(ident = PartialFoo, derive(Debug, PartialEq))]
#[required(ident = RequiredFoo, derive(Debug, PartialEq))]
#[pick(arg(ident = PickAB, fields(a, b), derive(Debug, PartialEq)))]
#[omit(arg(ident = OmitCD, fields(c, d), derive(Debug, PartialEq)))]
pub struct Foo {
    a: u8,
    b: Option<u8>,
    c: Option<Vec<u8>>,
}

The above code will generate the following code.

#[derive(Debug, PartialEq)]
pub struct PartialFoo {
    a: Option<u8>,
    b: Option<Option<u8>>,
    c: Option<Option<Vec<u8>>>,
}
#[derive(Debug, PartialEq)]
pub struct RequiredFoo {
    a: u8,
    b: u8,
    c: Vec<u8>,
}
#[derive(Debug, PartialEq)]
pub struct PickAB {
    a: u8,
    b: Option<u8>,
}
#[derive(Debug, PartialEq)]
pub struct OmitCD {
    a: u8,
    b: Option<u8>,
}

Some useful traits are also generated:

• From<Foo> for PartialFoo, PickAB, OmitCD
• From<PartialFoo> for Foo

Known Issue

Currently I don’t analyze which generic is used in the generated struct or enum. So rustc will complain if the field with generic is not included in the generated struct or enum.

Derive Macros

• Exclude
  Constructs an enum by excluding the set of variants from the original enum.
• Extract
  Constructs an enum by extracting the set of variants from the original enum.
• Omit
  Constructs a struct by omitting the set of fields from the original struct.
• Partial
  Constructs a struct with all fields of the original struct set to optional.
• Pick
  Constructs a struct by picking the set of fields from the original struct.
• Required
  Constructs a struct with all fields of the original struct set to required.