tia; trait, impl accessors | automatic

This is a syntax sugar proc-macro crate for trait, impl accessors patterns. tia generate to an accessor impls of an indivisual traits for any struct|enun|unions.

Features

• tia can be generate a impl codes automatically.
• Target types: struct | enum | union.
• Setting levels: {for all fields} | {per field}.
• trait supporting: Can be generate with multiple traits. (See also the Example-3 in below.)
• Generative accessors: Getter-like {move, Copy, &, &mut}, Setter-like { move, Copy, Clone, Into }. (See also the Example-1,2 and Reference/tia directive section.)
• Useful +features: { print, file-pretty, include, disable }. (See also the Reference/features section.)
• Naming patters: { prefix, suffix, fullname }. (See also the Reference/tia directive section.)

Example

Example-1; The introduction of tia

It is minimal, very simple version. Without traits complex.

use tia::Tia;  // 1. use

#[derive(Tia)] // 2. derive
#[tia(rg)]     // 3. tia directives
struct MyStruct
{
 foo: i32,
 bar: String
}

fn main()
{
 let mys = MyStruct{ foo: 123, bar: "Hello".into() };
 let foo = mys.get_foo(); // <-- 4. !! generated by tia automatically !!
 let bar = mys.get_bar(); // <-- 5. !! generated by tia automatically !!
 println!("foo={} bar={}", foo, bar );
}

cargo run, then you will get the output:

foo=123 bar=Hello

• (1,2) are preparing.
• (3) is tia directive for the struct-level.
• (4,5) are an automatic generated accessors by tia.

The automatic generated code is:

impl MyStruct
{
 pub fn get_foo(&self) -> &i32
 {
  &self.foo
 }

 pub fn get_bar(&self) -> &String
 {
  &self.bar
 }
}

It could be output to src/.tia/MyStruct if use file-pretty features in Cargo.toml:

[dependencies]
tia={ version="*", features=["file-pretty"] }

Example-2; A little complex/practical usage

use tia::Tia; // use

#[derive(Tia, Debug, Default)] // derive
#[tia(rg, s)] // <-- tia directives, for all fields
struct MyStruct
{
 #[tia(rmg)] // <-- #[tia(rg, s)] + #[tia(rmg)] => #[tia(rmg, s)]
 foo: i32,
 #[tia(rsi)] // <-- #[tia(rg, s)] + #[tia(rsi)] => #[tia(rg, rsi)]
 bar: String,

 baz: f64, // <-- #[tia(rg, s)]

 #[tia(g)] // <-- #[tia(rg, s)] + #[tia(g)] => #[tia(g, s)] !! NOTE: Could be use for Copy-ables such as u8, but g pattern could not be use non-Copy-ables such as Vec<u8>
 brabrabra: u8,

 #[tia(gm)] // <-- #[tia(rg, s)] + #[tia(g)] => #[tia(gm, s)] !! WARNING: Could be move any types, but gm pattern will drop self
 hogefuga: Vec<u8>
}

fn main()
{
 let mut mys = MyStruct::default();

 // rmg; reference-mut-getter
 // with per-field level directive overwriting.
 {
  let foo = mys.get_foo(); // <-- &mut i32
  *foo = 42;
  dbg!(&foo);
  dbg!(&mys);
 }

 // rsi: reference-setter-into
 // with per-field level directive overwriting.
 {
  let a: &str = "Hello, ";
  let b: String = String::from("tia.");
  let c: &String = &b;

  mys.set_bar(a); // &str
  println!("a: mys.bar = {}", mys.get_bar());

  mys.set_bar(b.clone()); // String; This effect move, thus the example is a -> c -> b
  println!("b: mys.bar = {}", mys.get_bar());

  mys.set_bar(c); // &String
  println!("c: mys.bar = {}", mys.get_bar());
 }

 let x = mys.get_brabrabra(); // it will be Copy, mys will live
 dbg!(x, &mys);

 let y = mys.get_hogefuga(); // gm, get-move accessor will be drop mys
 dbg!(y);
 // mys was dropped, it could not be compile.
 //dbg!(mys)
}

cargo run:

[src\main.rs:30] &foo = 42
[src\main.rs:31] &mys = MyStruct {
    foo: 42,
    bar: "",
    baz: 0.0,
    brabrabra: 0,
    hogefuga: [],
}
a: mys.bar = Hello,
b: mys.bar = tia.
c: mys.bar = tia.
[src\main.rs:52] x = 0
[src\main.rs:52] &mys = MyStruct {
    foo: 42,
    bar: "tia.",
    baz: 0.0,
    brabrabra: 0,
    hogefuga: [],
}
[src\main.rs:55] y = []

Example-3; trait usage

use tia::Tia;

trait FooGettable<T>{ fn get_foo(&self) -> T; }
trait Fruit{ fn get_bar(&self) -> &String; }
trait Sushi{ fn tuna(&self) -> u8; fn avocado(&mut self, v: u8); }

//include!(".tia/MyStruct.rs");
#[derive(Tia, Debug, Default)] // derive
struct MyStruct
{
 #[tia(s, "FooGettable<i32>", g)]
 foo: i32,
 #[tia("Fruit",rg,"",rsi)]
 bar: String,
 #[tia("Sushi",g*="tuna",s*="avocado")] // <- `g` and `s`: Sushi trait
 baz: u8
}

fn main()
{
 let mut mys = MyStruct::default();
 mys.set_foo(123);
 mys.set_bar("meow");
 let foo_gettable = &mys as &dyn FooGettable<i32>;
 let fruit = &mys as &dyn Fruit;
 println!("{}, {}", foo_gettable.get_foo(), fruit.get_bar() );
 let sushi = &mut mys as &mut dyn Sushi;
 sushi.avocado(32);
 println!("{}", sushi.tuna());
}

Then cargo run:

123, meow
32

The generated code with print, file or file-pretty features:

impl FooGettable<i32> for MyStruct
{
 fn get_foo(&self) -> i32
 {
  self.foo
 }
}
impl MyStruct
{
 pub fn set_bar<T: Into<String>>(&mut self, v: T)
 {
  self.bar = v.into();
 }

 pub fn set_foo(&mut self, v: i32)
 {
  self.foo = v;
 }
}
impl Fruit for MyStruct
{
 fn get_bar(&self) -> &String
 {
  &self.bar
 }
}
impl Sushi for MyStruct
{
 fn avocado(&mut self, v: u8)
 {
  self.baz = v;
 }

 fn tuna(&self) -> u8
 {
  self.baz
 }
}

Reference

Usage

1. Preparing, add tia="*" in [dependencies] section of the project Cargo.toml file. ( Or I like cargo add tia via cargo-edit )
   • FYI: The file-pretty features is good tool for your debugging. Read the bottom section "features" if you want.
2. Use:
   1. Write #[derive(Tia)] proc-macro on head of your struct|enum|union.
   2. Write #[tia(...)] proc-macro below the #[derive(Tia)] (for struct|enum|union-level settings) or top of the specific fields.
      • ... is explanate in the next section "tia directives".

tia directives

tia's proc-macro can parse the pattern:

#[tia( $tia_directive_0, $tia_directive_1,$tia_directive_2, ... )]

And the $tia_directive pattern:

1. Accessor directive
   • Accessors:
     • Getter accessor like:
       • gm => ([g]et [m]ove) ⚠ Move ⚠ pattern, it is NOT use for casually; like fn (self) -> i32 { self.value }
       • g => ([g]et) For Copy-able values, for use a primitive types such as u8, f32 or a impl Copy-ed types; like return &self.value.
       • rg => ([r]eference [g]et) Return a reference & pattern. It can be use in casually for most situations.
       • rmg => ([r]eference [m]ut [g]et) Return a reference mutable &mut. Sometimes useful, and sometimes so complex and difficult.
     • Setter accelike:
       • s => ([s]et) Raw value move pattern.
       • rs => ([r]eference [s]et) Reference & pattern, for Copy-able types.
       • rsc => ([r]eference [s]et [c]lone) Clone pattern, for Clone-able types such as String. This pattern require the same type for the input.
       • rsi => ([r]eference [s]et [i]nto) Into pattern, for Into-able types such as String. This pattern could be type conversions. For eg, &str|String|&String and more types are input to String with this pattern.
   • Naming policy
     • Default ( eg. g, rg rgi) => Getters are same as the Prefix with "get", Setters are same as the Prefix with "set".
     • g="my_awesome_prefix" => Prefix with specialized prefix-part string pattern. It will be generate fn my_awesome_prefix_xxxx for xxxx field symbol.
     • g+="my_awesome_suffix" => Suffix with specialized suffix-part string pattern. It will be generate fn xxxx_my_awesome_suffix for xxxx field symbol.
     • g*="my_awesome_fullname" => Fullname pattern. It will be generate fn my_awesome_fullname for a field.
2. Trait directive
   • Default ( no trait directives ) => It will be generate impl for MyStruct codes for a fields.
   • "TraitSymbol" => It will be generate impl TraitSymbol for MyStruct codes for a fields that appear in the after of this directive.
   • "" => It will be generate impl for MyStruct codes for a fields that appear in the after of this directive.

features

disable

Usage example:

[dependencies]
tia={ version="*", features=["disable"] }

• tia will be output nothing.
• But tia is not removed, thus it allow the #[derive(Tia)] and #[tia(...)] proc-macros with no effects.

print

Usage example:

[dependencies]
tia={ version="*", features=["print"] }

• tia will be output the generated code to STDERR.
  • But it is difficully to human eyes, thus file-pretty is better for human eyes.

file|file-pretty

Usage example:

[dependencies]
tia={ version="*", features=["file-pretty"] }

• tia will be output/update the generated code to the file such as src/.tia/MyStruct.rs.
• This file is not for use in build, but if you want check the generated code with your eyes then it helpful.

What's the difference of file and file-pretty:

• file will be output the raw generated code. It is very compressed.
• file-pretty will be output the raw generated code, and then apply rustfmt automatically.
  • note: this feature reqwire the rustfmt command in your development environment. (It is not a lib crate dependency.)

include|include-pretty|include-force

Usage example:

[dependencies]
tia={ version="*", features=["include-pretty"] }

tia will be:

1. Generate codes if not exists.
2. Generate include!(...) macro such as include!("src/.tia/MyStruct") instead.

What's the difference of include, include-pretty and include-force:

• include will be generate (=file) code if the generated code is not found.
• include-pretty will be generate and prettify (=file-pretty) if the generated code is not found.
• include-force will not be generate if the generated code is not found, maybe build will stop with an error(s).

Note

tia provide a useful syntax sugar, it will helpful if you should impl many interface-like specifications. For eg, something designed for object-oriented paradigm mainly languages such as C#, Java, C++, or complex data definition based by UML such as XMLSchema. But, it is just a syntax sugar. Please do not overdose tia unnecessarily.

LICENSE

• MIT

Contributor

• @yrashk

Thank you!😍

Author

• USAGI.NETWORK / Usagi Ito https://github.com/usagi/