abi_stable_derive/
parse_utils.rs

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1//! Functions for parsing many `syn` types.
2
3use as_derive_utils::ret_err_on_peek;
4
5use syn::{parse, punctuated::Punctuated, token::Add, TypeParamBound};
6
7use proc_macro2::Span;
8
9//use crate::utils::SynResultExt;
10
11pub(crate) fn parse_str_as_ident(lit: &str) -> syn::Ident {
12    syn::Ident::new(lit, Span::call_site())
13}
14
15pub(crate) fn parse_str_as_path(lit: &str) -> Result<syn::Path, syn::Error> {
16    syn::parse_str(lit)
17}
18
19pub(crate) fn parse_str_as_trait_bound(lit: &str) -> Result<syn::TraitBound, syn::Error> {
20    syn::parse_str(lit)
21}
22
23pub(crate) fn parse_str_as_type(lit: &str) -> Result<syn::Type, syn::Error> {
24    syn::parse_str(lit)
25}
26
27#[allow(dead_code)]
28pub(crate) fn parse_lit_as_type_bound(lit: &syn::LitStr) -> Result<TypeParamBound, syn::Error> {
29    lit.parse()
30}
31
32pub struct ParseBounds {
33    pub list: Punctuated<TypeParamBound, Add>,
34}
35
36impl parse::Parse for ParseBounds {
37    fn parse(input: parse::ParseStream) -> parse::Result<Self> {
38        ret_err_on_peek! {input, syn::Lit, "bound", "literal"}
39
40        let list = Punctuated::<TypeParamBound, Add>::parse_terminated(input).map_err(|e| {
41            let msg = format!("while parsing bounds: {}", e);
42            syn::Error::new(e.span(), msg)
43        })?;
44
45        if list.is_empty() {
46            Err(input.error("type bounds can't be empty"))
47        } else {
48            Ok(Self { list })
49        }
50    }
51}
52
53pub struct ParsePunctuated<T, P> {
54    pub list: Punctuated<T, P>,
55}
56
57impl<T, P> parse::Parse for ParsePunctuated<T, P>
58where
59    T: parse::Parse,
60    P: parse::Parse,
61{
62    fn parse(input: parse::ParseStream) -> parse::Result<Self> {
63        Ok(Self {
64            list: Punctuated::parse_terminated(input)?,
65        })
66    }
67}
abi_stable_derive/parse_utils.rs

abi_stable_derive/
parse_utils.rs
