File size: 4,547 Bytes
2409829 |
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 |
use proc_macro2::{Ident, TokenStream};
use std::collections::HashMap;
use syn::parse::{Parse, ParseStream};
use syn::punctuated::Punctuated;
use syn::token::Paren;
use syn::{LitStr, Token, parenthesized};
pub struct IdentList {
pub parts: Punctuated<Ident, Token![,]>,
}
impl Parse for IdentList {
fn parse(input: ParseStream) -> syn::Result<Self> {
let content;
let _paren_token = parenthesized!(content in input);
Ok(Self {
parts: Punctuated::parse_terminated(&content)?,
})
}
}
/// Parses `("some text")`
pub struct AttrInnerSingleString {
_paren_token: Paren,
pub content: LitStr,
}
impl Parse for AttrInnerSingleString {
fn parse(input: ParseStream) -> syn::Result<Self> {
let content;
let _paren_token = parenthesized!(content in input);
Ok(Self {
_paren_token,
content: content.parse()?,
})
}
}
/// Parses `key="value"`
pub struct KeyEqString {
key: Ident,
_eq_token: Token![=],
lit: LitStr,
}
impl Parse for KeyEqString {
fn parse(input: ParseStream) -> syn::Result<Self> {
Ok(Self {
key: input.parse()?,
_eq_token: input.parse()?,
lit: input.parse()?,
})
}
}
/// Parses `(key="value", key="value", …)`
pub struct AttrInnerKeyStringMap {
parts: Punctuated<KeyEqString, Token![,]>,
}
impl Parse for AttrInnerKeyStringMap {
fn parse(input: ParseStream) -> syn::Result<Self> {
Ok(Self {
parts: Punctuated::parse_terminated(input)?,
})
}
}
impl AttrInnerKeyStringMap {
pub fn multi_into_iter(iter: impl IntoIterator<Item = Self>) -> impl Iterator<Item = (Ident, Vec<LitStr>)> {
use std::collections::hash_map::Entry;
let mut res = Vec::<(Ident, Vec<LitStr>)>::new();
let mut idx = HashMap::<Ident, usize>::new();
for part in iter.into_iter().flat_map(|x: Self| x.parts) {
match idx.entry(part.key) {
Entry::Occupied(occ) => {
res[*occ.get()].1.push(part.lit);
}
Entry::Vacant(vac) => {
let ident = vac.key().clone();
vac.insert(res.len());
res.push((ident, vec![part.lit]));
}
}
}
res.into_iter()
}
}
/// Parses `(left, right)`
pub struct Pair<F, S> {
pub first: F,
pub sep: Token![,],
pub second: S,
}
impl<F, S> Parse for Pair<F, S>
where
F: Parse,
S: Parse,
{
fn parse(input: ParseStream) -> syn::Result<Self> {
Ok(Self {
first: input.parse()?,
sep: input.parse()?,
second: input.parse()?,
})
}
}
/// parses `(...)`
pub struct ParenthesizedTokens {
pub paren: Paren,
pub tokens: TokenStream,
}
impl Parse for ParenthesizedTokens {
fn parse(input: ParseStream) -> syn::Result<Self> {
let content;
let paren = parenthesized!(content in input);
Ok(Self { paren, tokens: content.parse()? })
}
}
/// parses a comma-delimeted list of `T`s with optional trailing comma
pub struct SimpleCommaDelimeted<T>(pub Vec<T>);
impl<T: Parse> Parse for SimpleCommaDelimeted<T> {
fn parse(input: ParseStream) -> syn::Result<Self> {
let punctuated = Punctuated::<T, Token![,]>::parse_terminated(input)?;
Ok(Self(punctuated.into_iter().collect()))
}
}
#[cfg(test)]
mod tests {
use super::*;
#[test]
fn attr_inner_single_string() {
let res = syn::parse2::<AttrInnerSingleString>(quote::quote! {
("a string literal")
});
assert!(res.is_ok());
assert_eq!(res.ok().unwrap().content.value(), "a string literal");
let res = syn::parse2::<AttrInnerSingleString>(quote::quote! {
wrong, "stuff"
});
assert!(res.is_err());
}
#[test]
fn key_eq_string() {
let res = syn::parse2::<KeyEqString>(quote::quote! {
key="value"
});
assert!(res.is_ok());
let res = res.ok().unwrap();
assert_eq!(res.key, "key");
assert_eq!(res.lit.value(), "value");
let res = syn::parse2::<KeyEqString>(quote::quote! {
wrong, "stuff"
});
assert!(res.is_err());
}
#[test]
fn attr_inner_key_string_map() {
let res = syn::parse2::<AttrInnerKeyStringMap>(quote::quote! {
key="value", key2="value2"
});
assert!(res.is_ok());
let res = res.ok().unwrap();
for (item, (k, v)) in res.parts.into_iter().zip(vec![("key", "value"), ("key2", "value2")]) {
assert_eq!(item.key, k);
assert_eq!(item.lit.value(), v);
}
let res = syn::parse2::<AttrInnerKeyStringMap>(quote::quote! {
key="value", key2="value2",
});
assert!(res.is_ok());
let res = res.ok().unwrap();
for (item, (k, v)) in res.parts.into_iter().zip(vec![("key", "value"), ("key2", "value2")]) {
assert_eq!(item.key, k);
assert_eq!(item.lit.value(), v);
}
let res = syn::parse2::<AttrInnerKeyStringMap>(quote::quote! {
wrong, "stuff"
});
assert!(res.is_err());
}
}
|