shellfn_attribute/
lib.rs

1#![recursion_limit = "128"]
2extern crate proc_macro;
3
4mod attributes;
5mod block_builder;
6mod output_type;
7mod utils;
8
9use crate::attributes::Attributes;
10use crate::block_builder::BlockBuilder;
11use darling::FromMeta;
12use proc_macro::TokenStream;
13use quote::quote;
14use syn::{Expr, ExprLit, Lit, Stmt};
15
16#[proc_macro_attribute]
17pub fn shell(attr: TokenStream, input: TokenStream) -> TokenStream {
18    let input = syn::parse_macro_input!(input as syn::ItemFn);
19
20    let parsed_attrs = match darling::ast::NestedMeta::parse_meta_list(attr.into()) {
21        Ok(v) => v,
22        Err(e) => {
23            return TokenStream::from(darling::Error::from(e).write_errors());
24        }
25    };
26    let attrs = match Attributes::from_list(&parsed_attrs) {
27        Ok(v) => v,
28        Err(e) => {
29            return TokenStream::from(e.write_errors());
30        }
31    };
32
33    if let Some(Stmt::Expr(
34        Expr::Lit(ExprLit {
35            lit: Lit::Str(ref program),
36            ..
37        }),
38        _,
39    )) = input.block.stmts.first()
40    {
41        let mut result = input.clone();
42        let program = program.value();
43        let block = BlockBuilder::new()
44            .with_program(program)
45            .with_attrs(attrs)
46            .with_args(input.sig.inputs.iter())
47            .with_return_type(input.sig.output)
48            .build();
49
50        result.block = syn::parse2(block).expect("generated invalid block");
51
52        (quote! {
53            #result
54        })
55        .into()
56    } else {
57        panic!(
58            r"Invalid input. Expected fn containing only string literal without any other statements"
59        )
60    }
61}
shellfn_attribute/lib.rs

shellfn_attribute/
lib.rs
