# syn-rsx
[](https://crates.io/crates/syn-rsx)
[](https://docs.rs/syn-rsx/)
[](https://codecov.io/gh/stoically/syn-rsx)
[syn](https://github.com/dtolnay/syn)-powered parser for JSX-like [TokenStreams](https://doc.rust-lang.org/proc_macro/struct.TokenStream.html), aka RSX. The parsed result is a nested `Node` structure, similar to the browser DOM, where node name and value are syn expressions to support building proc macros.
```rust
use quote::quote;
use syn_rsx::parse2;
let tokens = quote! { <hello world>"hi"</hello> };
let nodes = parse2(tokens).unwrap();
assert_eq!(nodes[0].name_as_string().unwrap(), "hello");
assert_eq!(nodes[0].attributes[0].name_as_string().unwrap(), "world");
assert_eq!(nodes[0].children[0].value_as_string().unwrap(), "hi");
```
## Features
- **Not opinionated**
Every tag or attribute name is valid
```html
<hello world />
```
- **Text nodes**
```html
<div>"String literal"</div>
```
Support for [unquoted text is planned]
- **Node names separated by dash, colon or double colon**
```html
<tag-name attribute-key="value" />
<tag:name attribute:key="value" />
<tag::name attribute::key="value" />
```
- **Node names with reserved keywords**
```html
<input type="submit" />
```
- **Attribute values can be any valid syn expression without requiring braces**
```html
<div key="some::value()" />
```
- **Doctypes, Comments and Fragments**
```html
<!DOCTYPE html>
<!-- "comment" -->
<></>
```
- **Braced blocks are parsed as arbitrary Rust code**
```html
<{ let block = "in node name position"; } />
<div>{ let block = "in node position"; }</div>
<div { let block="in attribute position" ; } />
<div key="{" let block="in attribute value position" ; } />
```
- **Helpful error reporting out of the box**
```rust,no-run
error: open tag has no corresponding close tag and is not self-closing
--> examples/html-to-string-macro/tests/lib.rs:5:24
|
5 | html_to_string! { <div> };
| ^^^
```
- **Customization**
A `ParserConfig` to customize parsing behavior is available, so if you have
slightly different requirements for parsing and it's not yet customizable
feel free to open an issue or pull request to extend the configuration.
One highlight with regards to customization is the `transform_block`
configuration, which takes a closure that receives raw block content as
`ParseStream` and lets you optionally convert it to a `TokenStream`. That makes it
possible to have custom syntax in blocks. More details in [#9]
[`syn`]: /syn
[`tokenstream`]: https://doc.rust-lang.org/proc_macro/struct.TokenStream.html
[unquoted text is planned]: https://github.com/stoically/syn-rsx/issues/2
[#9]: https://github.com/stoically/syn-rsx/issues/9