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fncmd_impl/
lib.rs

1use darling::FromMeta;
2use proc_macro::{Span, TokenStream};
3use proc_macro_error::proc_macro_error;
4use syn::{parse_macro_input, AttributeArgs, ItemFn};
5
6mod models;
7use models::*;
8mod context;
9use context::*;
10
11/// The `fncmd` macro. This can only be applied to the `main` function.
12///
13/// ```rust
14/// /// Description of the command line tool
15/// #[fncmd::fncmd]
16/// pub fn main(
17///   /// Argument foo
18///   #[opt(short, long)]
19///   foo: String,
20///   /// Argument bar
21///   #[opt(short, long)]
22///   bar: Option<String>,
23/// ) {
24///   println!("{:?} {:?}", foo, bar);
25/// }
26/// ```
27#[proc_macro_error]
28#[proc_macro_attribute]
29pub fn fncmd(attr: TokenStream, item: TokenStream) -> TokenStream {
30	// Get information about the target and package.
31	let call_site = Span::call_site();
32	let (target, package) = CONTEXT.get_target_and_package_of(&call_site);
33	let name = target.name.clone();
34	let version = package.version.to_string();
35	let subcmds = FncmdSubcmds::from((target, package));
36
37	// Parse the input tokens.
38	let attr = parse_macro_input!(attr as AttributeArgs);
39	let attr = FncmdAttr::from_list(&attr).unwrap();
40	let item = parse_macro_input!(item as ItemFn);
41	Fncmd::parse(name, version, attr, item, subcmds).into()
42}