# SimpleML Macro
This crate is an extension of [simpleml](https://crates.io/crates/simpleml). It
creates an "sml" macro to allow you to declare SML-based config within your
code.
## Patch Notes
### 3.0.1
Fixing README being out of date and updated to use SimpleML v4.0.0. No code
changes.
### 3.0.0
Updating the dependency on
[tree_iterators_rs](https://crates.io/crates/tree_iterators_rs) to version 3.2
to get new features.
### 2.0.0
Updating the dependency on
[tree_iterators_rs](https://crates.io/crates/tree_iterators_rs) to version 2.0
for better performance. This is a breaking change and all consumers will need to
update their code to get these performance benefits. If performance is not a
problem for you, there is no reason to switch.
### 1.0.1
[Fixes a macro panic when null values are used](https://github.com/mr-adult/SimpleML/issues/1)
## Usage
In order to use this macro, add the following to your Cargo.toml. NOTE: This
macro requires the nightly compiler for the
[proc_macro_span](https://github.com/rust-lang/rust/issues/54725) feature.
```toml
[dependencies]
tree_iterators_rs = "2.0"
simpleml = "2.0"
simpleml_macro = "2.0"
```
Once you have these dependencies in place, simply add a using for the macro, and
use it in your code. As an example, let's convert the following in-line
declaration of the SML data structure over to using the macro. This example
comes from the README.md file of [simpleml](https://crates.io/crates/simpleml).
### Before
```rust
use tree_iterators_rs::prelude::*;
use simpleml::{SMLWriter, SMLElement, SMLAttribute};
let my_sml_values = Tree {
value: SMLElement {
name: "Configuration",
attributes: Vec::with_capacity(0),
},
children: vec![
Tree {
value: SMLElement {
name: "Video",
attributes: vec![
SMLAttribute {
name: "Resolution",
values: vec![Some("1280"), Some("720")],
},
SMLAttribute {
name: "RefreshRate",
values: vec![Some("60")],
},
SMLAttribute {
name: "Fullscreen",
values: vec![Some("true")],
},
],
},
children: Vec::new(),
},
Tree {
value: SMLElement {
name: "Audio",
attributes: vec![
SMLAttribute {
name: "Volume",
values: vec![Some("100")],
},
SMLAttribute {
name: "Music",
values: vec![Some("80")],
},
],
},
children: Vec::new(),
},
Tree {
value: SMLElement {
name: "Player",
attributes: vec![SMLAttribute {
name: "Name",
values: vec![Some("Hero 123")],
}],
},
children: Vec::new(),
},
],
};
```
### After
```rust
use simpleml_macro::sml;
let my_sml_values = sml!{
Configuration
Video
Resolution 1280 720
RefreshRate 60
Fullscreen true
my_custom_end_keyword
Audio
Volume 100
Music 80
my_custom_end_keyword
Player
Name "Hero 123"
my_custom_end_keyword
my_custom_end_keyword
};
```