ast_description_lang/
tokens.rs

1use crate::{Config, Specs};
2use anyhow::{anyhow, Result};
3use proc_macro2::TokenStream;
4use quote::{format_ident, quote};
5use std::str::FromStr;
6
7impl Specs<'_> {
8  pub fn generate_tokens_mod(&self, config: &Config<'_>) -> Result<TokenStream> {
9    let error = TokenStream::from_str(config.error).map_err(|err| anyhow!("{err}"))?;
10    let tokens_mod = TokenStream::from_str(config.tokens_mod).map_err(|err| anyhow!("{err}"))?;
11
12    let enum_ = self.generate_tokens_enum();
13    let fmt = self.generate_tokens_fmt();
14    let parse = self.generate_tokens_parse(error, tokens_mod);
15    Ok(quote! {
16      #![allow(dead_code)]
17      #enum_
18      #fmt
19      #parse
20    })
21  }
22
23  fn generate_tokens_enum(&self) -> TokenStream {
24    let dynamic_tokens = self.dynamic_tokens.iter().map(|token| {
25      let name = token.0.as_type();
26      let pattern = token.1;
27      let constructor = format_ident!("make_{}", token.0 .0);
28      quote! {
29        #[regex(#pattern, super::#constructor)]
30        #name(super::#name)
31      }
32    });
33
34    let static_tokens = self.static_tokens.iter().map(|(name, keyword)| {
35      let name = name.as_type();
36      quote! {
37        #[token(#keyword)]
38        #name
39      }
40    });
41
42    quote! {
43      #[derive(Clone, Debug, logos::Logos, Eq, PartialEq, Hash)]
44      pub enum Token {
45        #[regex(r"\s+", logos::skip)]
46        #[error]
47        Error,
48
49        #(#dynamic_tokens),*,
50        #(#static_tokens),*,
51      }
52    }
53  }
54
55  fn generate_tokens_fmt(&self) -> TokenStream {
56    let dynamic_tokens = self.dynamic_tokens.iter().map(|(token, _)| {
57      let token = token.as_type();
58      quote! { Token::#token(value) => std::fmt::Display::fmt(value, f) }
59    });
60
61    let static_tokens = self.static_tokens.iter().map(|(token, symbol)| {
62      let token = token.as_type();
63      quote! { Token::#token => write!(f, "{}", #symbol) }
64    });
65
66    quote! {
67      impl std::fmt::Display for Token {
68        fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
69          #[allow(clippy::write_literal)]
70          match self {
71            Token::Error => write!(f, "INVALID_TOKEN"),
72            #(#dynamic_tokens),*,
73            #(#static_tokens),*,
74          }
75        }
76      }
77    }
78  }
79
80  fn generate_tokens_parse(&self, error: TokenStream, tokens_mod: TokenStream) -> TokenStream {
81    let static_tokens = self.static_tokens.iter().map(|(ident, _)| {
82      let ty = ident.as_type();
83      quote! {
84        pub fn #ident() -> impl Parser<Token, (), Error = Error> + Clone {
85          just(Token::#ty).ignored()
86        }
87      }
88    });
89
90    let dynamic_tokens = self.dynamic_tokens.iter().map(|(ident, _)| {
91      let ty = ident.as_type();
92      quote! {
93        pub fn #ident() -> impl Parser<Token, super::super::#ty, Error = Error> {
94          select!{ Token::#ty(value) => value }
95        }
96      }
97    });
98
99    quote! {
100      pub mod parse {
101        use chumsky::prelude::*;
102        #[allow(unused_imports)]
103        use #tokens_mod::{self, Token};
104
105        type Error = #error;
106
107        #(#static_tokens)*
108        #(#dynamic_tokens)*
109      }
110    }
111  }
112}
ast_description_lang/tokens.rs

ast_description_lang/
tokens.rs
