Revision control
Copy as Markdown
Other Tools
use self::get_span::{GetSpan, GetSpanBase, GetSpanInner};
use crate::{IdentFragment, ToTokens, TokenStreamExt};
use core::fmt;
use core::iter;
use core::ops::BitOr;
use proc_macro2::{Group, Ident, Punct, Spacing, TokenTree};
#[doc(hidden)]
pub use alloc::format;
#[doc(hidden)]
pub use core::option::Option;
#[doc(hidden)]
pub type Delimiter = proc_macro2::Delimiter;
#[doc(hidden)]
pub type Span = proc_macro2::Span;
#[doc(hidden)]
pub type TokenStream = proc_macro2::TokenStream;
#[doc(hidden)]
pub struct HasIterator; // True
#[doc(hidden)]
pub struct ThereIsNoIteratorInRepetition; // False
impl BitOr<ThereIsNoIteratorInRepetition> for ThereIsNoIteratorInRepetition {
type Output = ThereIsNoIteratorInRepetition;
fn bitor(self, _rhs: ThereIsNoIteratorInRepetition) -> ThereIsNoIteratorInRepetition {
ThereIsNoIteratorInRepetition
}
}
impl BitOr<ThereIsNoIteratorInRepetition> for HasIterator {
type Output = HasIterator;
fn bitor(self, _rhs: ThereIsNoIteratorInRepetition) -> HasIterator {
HasIterator
}
}
impl BitOr<HasIterator> for ThereIsNoIteratorInRepetition {
type Output = HasIterator;
fn bitor(self, _rhs: HasIterator) -> HasIterator {
HasIterator
}
}
impl BitOr<HasIterator> for HasIterator {
type Output = HasIterator;
fn bitor(self, _rhs: HasIterator) -> HasIterator {
HasIterator
}
}
/// Extension traits used by the implementation of `quote!`. These are defined
/// in separate traits, rather than as a single trait due to ambiguity issues.
///
/// These traits expose a `quote_into_iter` method which should allow calling
/// whichever impl happens to be applicable. Calling that method repeatedly on
/// the returned value should be idempotent.
#[doc(hidden)]
pub mod ext {
use super::RepInterp;
use super::{HasIterator as HasIter, ThereIsNoIteratorInRepetition as DoesNotHaveIter};
use crate::ToTokens;
use alloc::collections::btree_set::{self, BTreeSet};
use core::slice;
/// Extension trait providing the `quote_into_iter` method on iterators.
#[doc(hidden)]
pub trait RepIteratorExt: Iterator + Sized {
fn quote_into_iter(self) -> (Self, HasIter) {
(self, HasIter)
}
}
impl<T: Iterator> RepIteratorExt for T {}
/// Extension trait providing the `quote_into_iter` method for
/// non-iterable types. These types interpolate the same value in each
/// iteration of the repetition.
#[doc(hidden)]
pub trait RepToTokensExt {
/// Pretend to be an iterator for the purposes of `quote_into_iter`.
/// This allows repeated calls to `quote_into_iter` to continue
/// correctly returning DoesNotHaveIter.
fn next(&self) -> Option<&Self> {
Some(self)
}
fn quote_into_iter(&self) -> (&Self, DoesNotHaveIter) {
(self, DoesNotHaveIter)
}
}
impl<T: ToTokens + ?Sized> RepToTokensExt for T {}
/// Extension trait providing the `quote_into_iter` method for types that
/// can be referenced as an iterator.
#[doc(hidden)]
pub trait RepAsIteratorExt<'q> {
type Iter: Iterator;
fn quote_into_iter(&'q self) -> (Self::Iter, HasIter);
}
impl<'q, 'a, T: RepAsIteratorExt<'q> + ?Sized> RepAsIteratorExt<'q> for &'a T {
type Iter = T::Iter;
fn quote_into_iter(&'q self) -> (Self::Iter, HasIter) {
<T as RepAsIteratorExt>::quote_into_iter(*self)
}
}
impl<'q, 'a, T: RepAsIteratorExt<'q> + ?Sized> RepAsIteratorExt<'q> for &'a mut T {
type Iter = T::Iter;
fn quote_into_iter(&'q self) -> (Self::Iter, HasIter) {
<T as RepAsIteratorExt>::quote_into_iter(*self)
}
}
impl<'q, T: 'q> RepAsIteratorExt<'q> for [T] {
type Iter = slice::Iter<'q, T>;
fn quote_into_iter(&'q self) -> (Self::Iter, HasIter) {
(self.iter(), HasIter)
}
}
impl<'q, T: 'q> RepAsIteratorExt<'q> for Vec<T> {
type Iter = slice::Iter<'q, T>;
fn quote_into_iter(&'q self) -> (Self::Iter, HasIter) {
(self.iter(), HasIter)
}
}
impl<'q, T: 'q> RepAsIteratorExt<'q> for BTreeSet<T> {
type Iter = btree_set::Iter<'q, T>;
fn quote_into_iter(&'q self) -> (Self::Iter, HasIter) {
(self.iter(), HasIter)
}
}
impl<'q, T: RepAsIteratorExt<'q>> RepAsIteratorExt<'q> for RepInterp<T> {
type Iter = T::Iter;
fn quote_into_iter(&'q self) -> (Self::Iter, HasIter) {
self.0.quote_into_iter()
}
}
}
// Helper type used within interpolations to allow for repeated binding names.
// Implements the relevant traits, and exports a dummy `next()` method.
#[derive(Copy, Clone)]
#[doc(hidden)]
pub struct RepInterp<T>(pub T);
impl<T> RepInterp<T> {
// This method is intended to look like `Iterator::next`, and is called when
// a name is bound multiple times, as the previous binding will shadow the
// original `Iterator` object. This allows us to avoid advancing the
// iterator multiple times per iteration.
pub fn next(self) -> Option<T> {
Some(self.0)
}
}
impl<T: Iterator> Iterator for RepInterp<T> {
type Item = T::Item;
fn next(&mut self) -> Option<Self::Item> {
self.0.next()
}
}
impl<T: ToTokens> ToTokens for RepInterp<T> {
fn to_tokens(&self, tokens: &mut TokenStream) {
self.0.to_tokens(tokens);
}
}
#[doc(hidden)]
#[inline]
pub fn get_span<T>(span: T) -> GetSpan<T> {
GetSpan(GetSpanInner(GetSpanBase(span)))
}
mod get_span {
use core::ops::Deref;
use proc_macro2::extra::DelimSpan;
use proc_macro2::Span;
pub struct GetSpan<T>(pub(crate) GetSpanInner<T>);
pub struct GetSpanInner<T>(pub(crate) GetSpanBase<T>);
pub struct GetSpanBase<T>(pub(crate) T);
impl GetSpan<Span> {
#[inline]
pub fn __into_span(self) -> Span {
((self.0).0).0
}
}
impl GetSpanInner<DelimSpan> {
#[inline]
pub fn __into_span(&self) -> Span {
(self.0).0.join()
}
}
impl<T> GetSpanBase<T> {
#[allow(clippy::unused_self)]
pub fn __into_span(&self) -> T {
unreachable!()
}
}
impl<T> Deref for GetSpan<T> {
type Target = GetSpanInner<T>;
#[inline]
fn deref(&self) -> &Self::Target {
&self.0
}
}
impl<T> Deref for GetSpanInner<T> {
type Target = GetSpanBase<T>;
#[inline]
fn deref(&self) -> &Self::Target {
&self.0
}
}
}
#[doc(hidden)]
pub fn push_group(tokens: &mut TokenStream, delimiter: Delimiter, inner: TokenStream) {
tokens.append(Group::new(delimiter, inner));
}
#[doc(hidden)]
pub fn push_group_spanned(
tokens: &mut TokenStream,
span: Span,
delimiter: Delimiter,
inner: TokenStream,
) {
let mut g = Group::new(delimiter, inner);
g.set_span(span);
tokens.append(g);
}
#[doc(hidden)]
pub fn parse(tokens: &mut TokenStream, s: &str) {
let s: TokenStream = s.parse().expect("invalid token stream");
tokens.extend(iter::once(s));
}
#[doc(hidden)]
pub fn parse_spanned(tokens: &mut TokenStream, span: Span, s: &str) {
let s: TokenStream = s.parse().expect("invalid token stream");
tokens.extend(s.into_iter().map(|t| respan_token_tree(t, span)));
}
// Token tree with every span replaced by the given one.
fn respan_token_tree(mut token: TokenTree, span: Span) -> TokenTree {
match &mut token {
TokenTree::Group(g) => {
let stream = g
.stream()
.into_iter()
.map(|token| respan_token_tree(token, span))
.collect();
*g = Group::new(g.delimiter(), stream);
g.set_span(span);
}
other => other.set_span(span),
}
token
}
#[doc(hidden)]
pub fn push_ident(tokens: &mut TokenStream, s: &str) {
let span = Span::call_site();
push_ident_spanned(tokens, span, s);
}
#[doc(hidden)]
pub fn push_ident_spanned(tokens: &mut TokenStream, span: Span, s: &str) {
tokens.append(ident_maybe_raw(s, span));
}
#[doc(hidden)]
pub fn push_lifetime(tokens: &mut TokenStream, lifetime: &str) {
struct Lifetime<'a> {
name: &'a str,
state: u8,
}
impl<'a> Iterator for Lifetime<'a> {
type Item = TokenTree;
fn next(&mut self) -> Option<Self::Item> {
match self.state {
0 => {
self.state = 1;
Some(TokenTree::Punct(Punct::new('\'', Spacing::Joint)))
}
1 => {
self.state = 2;
Some(TokenTree::Ident(Ident::new(self.name, Span::call_site())))
}
_ => None,
}
}
}
tokens.extend(Lifetime {
name: &lifetime[1..],
state: 0,
});
}
#[doc(hidden)]
pub fn push_lifetime_spanned(tokens: &mut TokenStream, span: Span, lifetime: &str) {
struct Lifetime<'a> {
name: &'a str,
span: Span,
state: u8,
}
impl<'a> Iterator for Lifetime<'a> {
type Item = TokenTree;
fn next(&mut self) -> Option<Self::Item> {
match self.state {
0 => {
self.state = 1;
let mut apostrophe = Punct::new('\'', Spacing::Joint);
apostrophe.set_span(self.span);
Some(TokenTree::Punct(apostrophe))
}
1 => {
self.state = 2;
Some(TokenTree::Ident(Ident::new(self.name, self.span)))
}
_ => None,
}
}
}
tokens.extend(Lifetime {
name: &lifetime[1..],
span,
state: 0,
});
}
macro_rules! push_punct {
($name:ident $spanned:ident $char1:tt) => {
#[doc(hidden)]
pub fn $name(tokens: &mut TokenStream) {
tokens.append(Punct::new($char1, Spacing::Alone));
}
#[doc(hidden)]
pub fn $spanned(tokens: &mut TokenStream, span: Span) {
let mut punct = Punct::new($char1, Spacing::Alone);
punct.set_span(span);
tokens.append(punct);
}
};
($name:ident $spanned:ident $char1:tt $char2:tt) => {
#[doc(hidden)]
pub fn $name(tokens: &mut TokenStream) {
tokens.append(Punct::new($char1, Spacing::Joint));
tokens.append(Punct::new($char2, Spacing::Alone));
}
#[doc(hidden)]
pub fn $spanned(tokens: &mut TokenStream, span: Span) {
let mut punct = Punct::new($char1, Spacing::Joint);
punct.set_span(span);
tokens.append(punct);
let mut punct = Punct::new($char2, Spacing::Alone);
punct.set_span(span);
tokens.append(punct);
}
};
($name:ident $spanned:ident $char1:tt $char2:tt $char3:tt) => {
#[doc(hidden)]
pub fn $name(tokens: &mut TokenStream) {
tokens.append(Punct::new($char1, Spacing::Joint));
tokens.append(Punct::new($char2, Spacing::Joint));
tokens.append(Punct::new($char3, Spacing::Alone));
}
#[doc(hidden)]
pub fn $spanned(tokens: &mut TokenStream, span: Span) {
let mut punct = Punct::new($char1, Spacing::Joint);
punct.set_span(span);
tokens.append(punct);
let mut punct = Punct::new($char2, Spacing::Joint);
punct.set_span(span);
tokens.append(punct);
let mut punct = Punct::new($char3, Spacing::Alone);
punct.set_span(span);
tokens.append(punct);
}
};
}
push_punct!(push_add push_add_spanned '+');
push_punct!(push_add_eq push_add_eq_spanned '+' '=');
push_punct!(push_and push_and_spanned '&');
push_punct!(push_and_and push_and_and_spanned '&' '&');
push_punct!(push_and_eq push_and_eq_spanned '&' '=');
push_punct!(push_at push_at_spanned '@');
push_punct!(push_bang push_bang_spanned '!');
push_punct!(push_caret push_caret_spanned '^');
push_punct!(push_caret_eq push_caret_eq_spanned '^' '=');
push_punct!(push_colon push_colon_spanned ':');
push_punct!(push_colon2 push_colon2_spanned ':' ':');
push_punct!(push_comma push_comma_spanned ',');
push_punct!(push_div push_div_spanned '/');
push_punct!(push_div_eq push_div_eq_spanned '/' '=');
push_punct!(push_dot push_dot_spanned '.');
push_punct!(push_dot2 push_dot2_spanned '.' '.');
push_punct!(push_dot3 push_dot3_spanned '.' '.' '.');
push_punct!(push_dot_dot_eq push_dot_dot_eq_spanned '.' '.' '=');
push_punct!(push_eq push_eq_spanned '=');
push_punct!(push_eq_eq push_eq_eq_spanned '=' '=');
push_punct!(push_ge push_ge_spanned '>' '=');
push_punct!(push_gt push_gt_spanned '>');
push_punct!(push_le push_le_spanned '<' '=');
push_punct!(push_lt push_lt_spanned '<');
push_punct!(push_mul_eq push_mul_eq_spanned '*' '=');
push_punct!(push_ne push_ne_spanned '!' '=');
push_punct!(push_or push_or_spanned '|');
push_punct!(push_or_eq push_or_eq_spanned '|' '=');
push_punct!(push_or_or push_or_or_spanned '|' '|');
push_punct!(push_pound push_pound_spanned '#');
push_punct!(push_question push_question_spanned '?');
push_punct!(push_rarrow push_rarrow_spanned '-' '>');
push_punct!(push_larrow push_larrow_spanned '<' '-');
push_punct!(push_rem push_rem_spanned '%');
push_punct!(push_rem_eq push_rem_eq_spanned '%' '=');
push_punct!(push_fat_arrow push_fat_arrow_spanned '=' '>');
push_punct!(push_semi push_semi_spanned ';');
push_punct!(push_shl push_shl_spanned '<' '<');
push_punct!(push_shl_eq push_shl_eq_spanned '<' '<' '=');
push_punct!(push_shr push_shr_spanned '>' '>');
push_punct!(push_shr_eq push_shr_eq_spanned '>' '>' '=');
push_punct!(push_star push_star_spanned '*');
push_punct!(push_sub push_sub_spanned '-');
push_punct!(push_sub_eq push_sub_eq_spanned '-' '=');
#[doc(hidden)]
pub fn push_underscore(tokens: &mut TokenStream) {
push_underscore_spanned(tokens, Span::call_site());
}
#[doc(hidden)]
pub fn push_underscore_spanned(tokens: &mut TokenStream, span: Span) {
tokens.append(Ident::new("_", span));
}
// Helper method for constructing identifiers from the `format_ident!` macro,
// handling `r#` prefixes.
#[doc(hidden)]
pub fn mk_ident(id: &str, span: Option<Span>) -> Ident {
let span = span.unwrap_or_else(Span::call_site);
ident_maybe_raw(id, span)
}
fn ident_maybe_raw(id: &str, span: Span) -> Ident {
if let Some(id) = id.strip_prefix("r#") {
Ident::new_raw(id, span)
} else {
Ident::new(id, span)
}
}
// Adapts from `IdentFragment` to `fmt::Display` for use by the `format_ident!`
// macro, and exposes span information from these fragments.
//
// This struct also has forwarding implementations of the formatting traits
// `Octal`, `LowerHex`, `UpperHex`, and `Binary` to allow for their use within
// `format_ident!`.
#[derive(Copy, Clone)]
#[doc(hidden)]
pub struct IdentFragmentAdapter<T: IdentFragment>(pub T);
impl<T: IdentFragment> IdentFragmentAdapter<T> {
pub fn span(&self) -> Option<Span> {
self.0.span()
}
}
impl<T: IdentFragment> fmt::Display for IdentFragmentAdapter<T> {
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
IdentFragment::fmt(&self.0, f)
}
}
impl<T: IdentFragment + fmt::Octal> fmt::Octal for IdentFragmentAdapter<T> {
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
fmt::Octal::fmt(&self.0, f)
}
}
impl<T: IdentFragment + fmt::LowerHex> fmt::LowerHex for IdentFragmentAdapter<T> {
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
fmt::LowerHex::fmt(&self.0, f)
}
}
impl<T: IdentFragment + fmt::UpperHex> fmt::UpperHex for IdentFragmentAdapter<T> {
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
fmt::UpperHex::fmt(&self.0, f)
}
}
impl<T: IdentFragment + fmt::Binary> fmt::Binary for IdentFragmentAdapter<T> {
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
fmt::Binary::fmt(&self.0, f)
}
}