1
//! Multi-language code generation backends for parsed CSS.
2
//!
3
//! The kernel of a future "compile UI to standalone project" feature exposed by
4
//! the `azul-dll` debug HTTP server: a parsed [`Css`](crate::css::Css) is fed to
5
//! a [`CodegenBackend`] implementation, which returns a complete source string
6
//! plus auxiliary files (e.g. `Cargo.toml`) for a target language.
7
//!
8
//! Today only [`rust::RustBackend`] is implemented; [`cpp`] and [`python`] hold
9
//! stub backends so the public API stays stable as new languages come online.
10

            
11
use alloc::{string::String, vec::Vec};
12

            
13
use crate::css::Css;
14

            
15
pub mod cpp;
16
pub mod format;
17
pub mod python;
18
pub mod rust;
19

            
20
/// One emitted source artifact (e.g. `src/main.rs`, `Cargo.toml`).
21
#[derive(Debug)]
22
pub struct GeneratedFile {
23
    pub path: String,
24
    pub contents: String,
25
}
26

            
27
/// Pluggable code-generation strategy. Each backend turns a parsed [`Css`] into
28
/// a list of files that, taken together, form a buildable standalone project.
29
pub trait CodegenBackend {
30
    /// Stable identifier (e.g. `"rust"`) used by the HTTP layer to pick a backend.
31
    fn lang(&self) -> &'static str;
32

            
33
    /// Render a single CSS expression. Useful for tests / quick previews where
34
    /// the caller doesn't want a full project layout.
35
    fn emit_css(&self, css: &Css) -> String;
36

            
37
    /// Emit a complete standalone project. The returned files are root-relative.
38
    fn emit_project(&self, css: &Css) -> Vec<GeneratedFile>;
39
}
40

            
41
/// Look up a backend by its [`CodegenBackend::lang`] identifier.
42
#[must_use] pub fn backend_for(lang: &str) -> Option<Box<dyn CodegenBackend>> {
43
    match lang {
44
        "rust" => Some(Box::new(rust::RustBackend)),
45
        "cpp" | "c++" => Some(Box::new(cpp::CppBackend)),
46
        "python" | "py" => Some(Box::new(python::PythonBackend)),
47
        _ => None,
48
    }
49
}