ppx_macros/
lib.rs

1#![cfg_attr(docsrs, feature(doc_cfg))]
2#![cfg_attr(feature = "nightly", feature(proc_macro_tracked_path))]
3
4use std::path::PathBuf;
5
6use proc_macro::Span;
7use syn::parse::Parse;
8use syn::{Expr, ExprArray, LitStr, Token};
9use quote::ToTokens;
10
11use ppx_impl as ppx;
12
13struct Args {
14    file_path: String,
15    base_path: String,
16    params: Vec<String>,
17}
18
19impl Parse for Args {
20    fn parse(input: syn::parse::ParseStream) -> syn::Result<Self> {
21        let file_path: LitStr = input.parse()?;
22        input.parse::<Token![,]>()?;
23
24        let mut params: Option<ExprArray> = None;
25        let base_path: LitStr = input.parse()?;
26        if input.peek(Token![,]) {
27            input.parse::<Token![,]>()?;
28            if !input.is_empty() {
29                params = Some(input.parse()?);
30            }
31        }
32
33        let params = params
34            .map(|params| {
35                params.elems
36                    .into_iter()
37                    .map(|elem| match elem {
38                        Expr::Lit(lit) => match &lit.lit {
39                            syn::Lit::Str(s) => s.value(),
40                            _ => panic!("Expected string literal in params"),
41                        },
42                        _ => panic!("Expected string literal in params")
43                    }).collect::<Vec<_>>()
44            })
45            .unwrap_or(Vec::new());
46
47        Ok(Args {
48            file_path: file_path.value(),
49            base_path: base_path.value(),
50            params: params
51        })
52    }
53}
54
55/// Parse a macro at compile time from a file.
56///
57/// # Example
58///
59/// ```no_run
60/// include_ppx_string!("path/to/file", "./templates", ["param1", "param2"])
61/// ```
62#[cfg(feature = "nightly")]
63#[proc_macro]
64pub fn include_ppx(input: proc_macro::TokenStream) -> proc_macro::TokenStream {
65    let args = syn::parse_macro_input!(input as Args);
66
67    let source_path = PathBuf::from(Span::call_site().file());
68    let base_path = source_path.parent().unwrap();
69
70    let file_path = base_path.join(args.file_path);
71    proc_macro::tracked::path(file_path.to_str().expect("File path was not UTF-8 encoded"));
72    let base_path = base_path.join(args.base_path);
73
74    let output = ppx::parse(file_path, base_path, args.params.iter().map(|s| s.as_str())).unwrap();
75    let output = LitStr::new(&output, Span::call_site().into());
76
77    return output.to_token_stream().into();
78}
79
80/// Parse a macro at compile time from a string.
81///
82/// # Example
83///
84/// ```rust
85/// # use ppx_macros::include_ppx_string;
86/// assert_eq!(
87///     include_ppx_string!("#define A Hello\nA", ".", []),
88///     "Hello"
89/// );
90/// ```
91#[proc_macro]
92pub fn include_ppx_string(input: proc_macro::TokenStream) -> proc_macro::TokenStream {
93    let args = syn::parse_macro_input!(input as Args);
94
95    let source_path = PathBuf::from(Span::call_site().file());
96    let base_path = source_path.parent().unwrap();
97
98    let contents = args.file_path;
99    let base_path = base_path.join(args.base_path);
100
101    let output = ppx::parse_string(&contents, base_path, args.params.iter().map(|s| s.as_str())).unwrap();
102    let output = LitStr::new(&output, Span::call_site().into());
103
104    return output.to_token_stream().into();
105}
ppx_macros/lib.rs

ppx_macros/
lib.rs
