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#[cfg(span_locations)]
use crate::location::LineColumn;
use crate::parse::{self, Cursor};
use crate::rcvec::{RcVec, RcVecBuilder, RcVecIntoIter, RcVecMut};
use crate::{Delimiter, Spacing, TokenTree};
#[cfg(all(span_locations, not(fuzzing)))]
use alloc::collections::BTreeMap;
#[cfg(all(span_locations, not(fuzzing)))]
use core::cell::RefCell;
#[cfg(span_locations)]
use core::cmp;
use core::fmt::{self, Debug, Display, Write};
use core::mem::ManuallyDrop;
use core::ops::RangeBounds;
use core::ptr;
use core::str::FromStr;
use std::path::PathBuf;
/// Force use of proc-macro2's fallback implementation of the API for now, even
/// if the compiler's implementation is available.
pub fn force() {
#[cfg(wrap_proc_macro)]
crate::detection::force_fallback();
}
/// Resume using the compiler's implementation of the proc macro API if it is
/// available.
pub fn unforce() {
#[cfg(wrap_proc_macro)]
crate::detection::unforce_fallback();
}
#[derive(Clone)]
pub(crate) struct TokenStream {
inner: RcVec<TokenTree>,
}
#[derive(Debug)]
pub(crate) struct LexError {
pub(crate) span: Span,
}
impl LexError {
pub(crate) fn span(&self) -> Span {
self.span
}
fn call_site() -> Self {
LexError {
span: Span::call_site(),
}
}
}
impl TokenStream {
pub fn new() -> Self {
TokenStream {
inner: RcVecBuilder::new().build(),
}
}
pub fn is_empty(&self) -> bool {
self.inner.len() == 0
}
fn take_inner(self) -> RcVecBuilder<TokenTree> {
let nodrop = ManuallyDrop::new(self);
unsafe { ptr::read(&nodrop.inner) }.make_owned()
}
}
fn push_token_from_proc_macro(mut vec: RcVecMut<TokenTree>, token: TokenTree) {
match token {
TokenTree::Literal(crate::Literal {
#[cfg(wrap_proc_macro)]
inner: crate::imp::Literal::Fallback(literal),
#[cfg(not(wrap_proc_macro))]
inner: literal,
..
}) if literal.repr.starts_with('-') => {
push_negative_literal(vec, literal);
}
_ => vec.push(token),
}
#[cold]
fn push_negative_literal(mut vec: RcVecMut<TokenTree>, mut literal: Literal) {
literal.repr.remove(0);
let mut punct = crate::Punct::new('-', Spacing::Alone);
punct.set_span(crate::Span::_new_fallback(literal.span));
vec.push(TokenTree::Punct(punct));
vec.push(TokenTree::Literal(crate::Literal::_new_fallback(literal)));
}
}
// Nonrecursive to prevent stack overflow.
impl Drop for TokenStream {
fn drop(&mut self) {
let mut inner = match self.inner.get_mut() {
Some(inner) => inner,
None => return,
};
while let Some(token) = inner.pop() {
let group = match token {
TokenTree::Group(group) => group.inner,
_ => continue,
};
#[cfg(wrap_proc_macro)]
let group = match group {
crate::imp::Group::Fallback(group) => group,
crate::imp::Group::Compiler(_) => continue,
};
inner.extend(group.stream.take_inner());
}
}
}
pub(crate) struct TokenStreamBuilder {
inner: RcVecBuilder<TokenTree>,
}
impl TokenStreamBuilder {
pub fn new() -> Self {
TokenStreamBuilder {
inner: RcVecBuilder::new(),
}
}
pub fn with_capacity(cap: usize) -> Self {
TokenStreamBuilder {
inner: RcVecBuilder::with_capacity(cap),
}
}
pub fn push_token_from_parser(&mut self, tt: TokenTree) {
self.inner.push(tt);
}
pub fn build(self) -> TokenStream {
TokenStream {
inner: self.inner.build(),
}
}
}
#[cfg(span_locations)]
fn get_cursor(src: &str) -> Cursor {
#[cfg(fuzzing)]
return Cursor { rest: src, off: 1 };
// Create a dummy file & add it to the source map
#[cfg(not(fuzzing))]
SOURCE_MAP.with(|cm| {
let mut cm = cm.borrow_mut();
let span = cm.add_file(src);
Cursor {
rest: src,
off: span.lo,
}
})
}
#[cfg(not(span_locations))]
fn get_cursor(src: &str) -> Cursor {
Cursor { rest: src }
}
impl FromStr for TokenStream {
type Err = LexError;
fn from_str(src: &str) -> Result<TokenStream, LexError> {
// Create a dummy file & add it to the source map
let mut cursor = get_cursor(src);
// Strip a byte order mark if present
const BYTE_ORDER_MARK: &str = "\u{feff}";
if cursor.starts_with(BYTE_ORDER_MARK) {
cursor = cursor.advance(BYTE_ORDER_MARK.len());
}
parse::token_stream(cursor)
}
}
impl Display for LexError {
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
f.write_str("cannot parse string into token stream")
}
}
impl Display for TokenStream {
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
let mut joint = false;
for (i, tt) in self.inner.iter().enumerate() {
if i != 0 && !joint {
write!(f, " ")?;
}
joint = false;
match tt {
TokenTree::Group(tt) => Display::fmt(tt, f),
TokenTree::Ident(tt) => Display::fmt(tt, f),
TokenTree::Punct(tt) => {
joint = tt.spacing() == Spacing::Joint;
Display::fmt(tt, f)
}
TokenTree::Literal(tt) => Display::fmt(tt, f),
}?;
}
Ok(())
}
}
impl Debug for TokenStream {
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
f.write_str("TokenStream ")?;
f.debug_list().entries(self.clone()).finish()
}
}
#[cfg(feature = "proc-macro")]
impl From<proc_macro::TokenStream> for TokenStream {
fn from(inner: proc_macro::TokenStream) -> Self {
inner
.to_string()
.parse()
.expect("compiler token stream parse failed")
}
}
#[cfg(feature = "proc-macro")]
impl From<TokenStream> for proc_macro::TokenStream {
fn from(inner: TokenStream) -> Self {
inner
.to_string()
.parse()
.expect("failed to parse to compiler tokens")
}
}
impl From<TokenTree> for TokenStream {
fn from(tree: TokenTree) -> Self {
let mut stream = RcVecBuilder::new();
push_token_from_proc_macro(stream.as_mut(), tree);
TokenStream {
inner: stream.build(),
}
}
}
impl FromIterator<TokenTree> for TokenStream {
fn from_iter<I: IntoIterator<Item = TokenTree>>(tokens: I) -> Self {
let mut stream = TokenStream::new();
stream.extend(tokens);
stream
}
}
impl FromIterator<TokenStream> for TokenStream {
fn from_iter<I: IntoIterator<Item = TokenStream>>(streams: I) -> Self {
let mut v = RcVecBuilder::new();
for stream in streams {
v.extend(stream.take_inner());
}
TokenStream { inner: v.build() }
}
}
impl Extend<TokenTree> for TokenStream {
fn extend<I: IntoIterator<Item = TokenTree>>(&mut self, tokens: I) {
let mut vec = self.inner.make_mut();
tokens
.into_iter()
.for_each(|token| push_token_from_proc_macro(vec.as_mut(), token));
}
}
impl Extend<TokenStream> for TokenStream {
fn extend<I: IntoIterator<Item = TokenStream>>(&mut self, streams: I) {
self.inner.make_mut().extend(streams.into_iter().flatten());
}
}
pub(crate) type TokenTreeIter = RcVecIntoIter<TokenTree>;
impl IntoIterator for TokenStream {
type Item = TokenTree;
type IntoIter = TokenTreeIter;
fn into_iter(self) -> TokenTreeIter {
self.take_inner().into_iter()
}
}
#[derive(Clone, PartialEq, Eq)]
pub(crate) struct SourceFile {
path: PathBuf,
}
impl SourceFile {
/// Get the path to this source file as a string.
pub fn path(&self) -> PathBuf {
self.path.clone()
}
pub fn is_real(&self) -> bool {
false
}
}
impl Debug for SourceFile {
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
f.debug_struct("SourceFile")
.field("path", &self.path())
.field("is_real", &self.is_real())
.finish()
}
}
#[cfg(all(span_locations, not(fuzzing)))]
thread_local! {
static SOURCE_MAP: RefCell<SourceMap> = RefCell::new(SourceMap {
// Start with a single dummy file which all call_site() and def_site()
// spans reference.
files: vec![FileInfo {
source_text: String::new(),
span: Span { lo: 0, hi: 0 },
lines: vec![0],
char_index_to_byte_offset: BTreeMap::new(),
}],
});
}
#[cfg(all(span_locations, not(fuzzing)))]
struct FileInfo {
source_text: String,
span: Span,
lines: Vec<usize>,
char_index_to_byte_offset: BTreeMap<usize, usize>,
}
#[cfg(all(span_locations, not(fuzzing)))]
impl FileInfo {
fn offset_line_column(&self, offset: usize) -> LineColumn {
assert!(self.span_within(Span {
lo: offset as u32,
hi: offset as u32,
}));
let offset = offset - self.span.lo as usize;
match self.lines.binary_search(&offset) {
Ok(found) => LineColumn {
line: found + 1,
column: 0,
},
Err(idx) => LineColumn {
line: idx,
column: offset - self.lines[idx - 1],
},
}
}
fn span_within(&self, span: Span) -> bool {
span.lo >= self.span.lo && span.hi <= self.span.hi
}
fn source_text(&mut self, span: Span) -> String {
let lo_char = (span.lo - self.span.lo) as usize;
// Look up offset of the largest already-computed char index that is
// less than or equal to the current requested one. We resume counting
// chars from that point.
let (&last_char_index, &last_byte_offset) = self
.char_index_to_byte_offset
.range(..=lo_char)
.next_back()
.unwrap_or((&0, &0));
let lo_byte = if last_char_index == lo_char {
last_byte_offset
} else {
let total_byte_offset = match self.source_text[last_byte_offset..]
.char_indices()
.nth(lo_char - last_char_index)
{
Some((additional_offset, _ch)) => last_byte_offset + additional_offset,
None => self.source_text.len(),
};
self.char_index_to_byte_offset
.insert(lo_char, total_byte_offset);
total_byte_offset
};
let trunc_lo = &self.source_text[lo_byte..];
let char_len = (span.hi - span.lo) as usize;
let source_text = match trunc_lo.char_indices().nth(char_len) {
Some((offset, _ch)) => &trunc_lo[..offset],
None => trunc_lo,
};
source_text.to_owned()
}
}
/// Computes the offsets of each line in the given source string
/// and the total number of characters
#[cfg(all(span_locations, not(fuzzing)))]
fn lines_offsets(s: &str) -> (usize, Vec<usize>) {
let mut lines = vec![0];
let mut total = 0;
for ch in s.chars() {
total += 1;
if ch == '\n' {
lines.push(total);
}
}
(total, lines)
}
#[cfg(all(span_locations, not(fuzzing)))]
struct SourceMap {
files: Vec<FileInfo>,
}
#[cfg(all(span_locations, not(fuzzing)))]
impl SourceMap {
fn next_start_pos(&self) -> u32 {
// Add 1 so there's always space between files.
//
// We'll always have at least 1 file, as we initialize our files list
// with a dummy file.
self.files.last().unwrap().span.hi + 1
}
fn add_file(&mut self, src: &str) -> Span {
let (len, lines) = lines_offsets(src);
let lo = self.next_start_pos();
let span = Span {
lo,
hi: lo + (len as u32),
};
self.files.push(FileInfo {
source_text: src.to_owned(),
span,
lines,
// Populated lazily by source_text().
char_index_to_byte_offset: BTreeMap::new(),
});
span
}
#[cfg(procmacro2_semver_exempt)]
fn filepath(&self, span: Span) -> PathBuf {
for (i, file) in self.files.iter().enumerate() {
if file.span_within(span) {
return PathBuf::from(if i == 0 {
"<unspecified>".to_owned()
} else {
format!("<parsed string {}>", i)
});
}
}
unreachable!("Invalid span with no related FileInfo!");
}
fn fileinfo(&self, span: Span) -> &FileInfo {
for file in &self.files {
if file.span_within(span) {
return file;
}
}
unreachable!("Invalid span with no related FileInfo!");
}
fn fileinfo_mut(&mut self, span: Span) -> &mut FileInfo {
for file in &mut self.files {
if file.span_within(span) {
return file;
}
}
unreachable!("Invalid span with no related FileInfo!");
}
}
#[derive(Clone, Copy, PartialEq, Eq)]
pub(crate) struct Span {
#[cfg(span_locations)]
pub(crate) lo: u32,
#[cfg(span_locations)]
pub(crate) hi: u32,
}
impl Span {
#[cfg(not(span_locations))]
pub fn call_site() -> Self {
Span {}
}
#[cfg(span_locations)]
pub fn call_site() -> Self {
Span { lo: 0, hi: 0 }
}
pub fn mixed_site() -> Self {
Span::call_site()
}
#[cfg(procmacro2_semver_exempt)]
pub fn def_site() -> Self {
Span::call_site()
}
pub fn resolved_at(&self, _other: Span) -> Span {
// Stable spans consist only of line/column information, so
// `resolved_at` and `located_at` only select which span the
// caller wants line/column information from.
*self
}
pub fn located_at(&self, other: Span) -> Span {
other
}
#[cfg(procmacro2_semver_exempt)]
pub fn source_file(&self) -> SourceFile {
#[cfg(fuzzing)]
return SourceFile {
path: PathBuf::from("<unspecified>"),
};
#[cfg(not(fuzzing))]
SOURCE_MAP.with(|cm| {
let cm = cm.borrow();
let path = cm.filepath(*self);
SourceFile { path }
})
}
#[cfg(span_locations)]
pub fn start(&self) -> LineColumn {
#[cfg(fuzzing)]
return LineColumn { line: 0, column: 0 };
#[cfg(not(fuzzing))]
SOURCE_MAP.with(|cm| {
let cm = cm.borrow();
let fi = cm.fileinfo(*self);
fi.offset_line_column(self.lo as usize)
})
}
#[cfg(span_locations)]
pub fn end(&self) -> LineColumn {
#[cfg(fuzzing)]
return LineColumn { line: 0, column: 0 };
#[cfg(not(fuzzing))]
SOURCE_MAP.with(|cm| {
let cm = cm.borrow();
let fi = cm.fileinfo(*self);
fi.offset_line_column(self.hi as usize)
})
}
#[cfg(not(span_locations))]
pub fn join(&self, _other: Span) -> Option<Span> {
Some(Span {})
}
#[cfg(span_locations)]
pub fn join(&self, other: Span) -> Option<Span> {
#[cfg(fuzzing)]
return {
let _ = other;
None
};
#[cfg(not(fuzzing))]
SOURCE_MAP.with(|cm| {
let cm = cm.borrow();
// If `other` is not within the same FileInfo as us, return None.
if !cm.fileinfo(*self).span_within(other) {
return None;
}
Some(Span {
lo: cmp::min(self.lo, other.lo),
hi: cmp::max(self.hi, other.hi),
})
})
}
#[cfg(not(span_locations))]
pub fn source_text(&self) -> Option<String> {
None
}
#[cfg(span_locations)]
pub fn source_text(&self) -> Option<String> {
#[cfg(fuzzing)]
return None;
#[cfg(not(fuzzing))]
{
if self.is_call_site() {
None
} else {
Some(SOURCE_MAP.with(|cm| cm.borrow_mut().fileinfo_mut(*self).source_text(*self)))
}
}
}
#[cfg(not(span_locations))]
pub(crate) fn first_byte(self) -> Self {
self
}
#[cfg(span_locations)]
pub(crate) fn first_byte(self) -> Self {
Span {
lo: self.lo,
hi: cmp::min(self.lo.saturating_add(1), self.hi),
}
}
#[cfg(not(span_locations))]
pub(crate) fn last_byte(self) -> Self {
self
}
#[cfg(span_locations)]
pub(crate) fn last_byte(self) -> Self {
Span {
lo: cmp::max(self.hi.saturating_sub(1), self.lo),
hi: self.hi,
}
}
#[cfg(span_locations)]
fn is_call_site(&self) -> bool {
self.lo == 0 && self.hi == 0
}
}
impl Debug for Span {
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
#[cfg(span_locations)]
return write!(f, "bytes({}..{})", self.lo, self.hi);
#[cfg(not(span_locations))]
write!(f, "Span")
}
}
pub(crate) fn debug_span_field_if_nontrivial(debug: &mut fmt::DebugStruct, span: Span) {
#[cfg(span_locations)]
{
if span.is_call_site() {
return;
}
}
if cfg!(span_locations) {
debug.field("span", &span);
}
}
#[derive(Clone)]
pub(crate) struct Group {
delimiter: Delimiter,
stream: TokenStream,
span: Span,
}
impl Group {
pub fn new(delimiter: Delimiter, stream: TokenStream) -> Self {
Group {
delimiter,
stream,
span: Span::call_site(),
}
}
pub fn delimiter(&self) -> Delimiter {
self.delimiter
}
pub fn stream(&self) -> TokenStream {
self.stream.clone()
}
pub fn span(&self) -> Span {
self.span
}
pub fn span_open(&self) -> Span {
self.span.first_byte()
}
pub fn span_close(&self) -> Span {
self.span.last_byte()
}
pub fn set_span(&mut self, span: Span) {
self.span = span;
}
}
impl Display for Group {
// We attempt to match libproc_macro's formatting.
// Empty parens: ()
// Nonempty parens: (...)
// Empty brackets: []
// Nonempty brackets: [...]
// Empty braces: { }
// Nonempty braces: { ... }
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
let (open, close) = match self.delimiter {
Delimiter::Parenthesis => ("(", ")"),
Delimiter::Brace => ("{ ", "}"),
Delimiter::Bracket => ("[", "]"),
Delimiter::None => ("", ""),
};
f.write_str(open)?;
Display::fmt(&self.stream, f)?;
if self.delimiter == Delimiter::Brace && !self.stream.inner.is_empty() {
f.write_str(" ")?;
}
f.write_str(close)?;
Ok(())
}
}
impl Debug for Group {
fn fmt(&self, fmt: &mut fmt::Formatter) -> fmt::Result {
let mut debug = fmt.debug_struct("Group");
debug.field("delimiter", &self.delimiter);
debug.field("stream", &self.stream);
debug_span_field_if_nontrivial(&mut debug, self.span);
debug.finish()
}
}
#[derive(Clone)]
pub(crate) struct Ident {
sym: String,
span: Span,
raw: bool,
}
impl Ident {
#[track_caller]
pub fn new_checked(string: &str, span: Span) -> Self {
validate_ident(string);
Ident::new_unchecked(string, span)
}
pub fn new_unchecked(string: &str, span: Span) -> Self {
Ident {
sym: string.to_owned(),
span,
raw: false,
}
}
#[track_caller]
pub fn new_raw_checked(string: &str, span: Span) -> Self {
validate_ident_raw(string);
Ident::new_raw_unchecked(string, span)
}
pub fn new_raw_unchecked(string: &str, span: Span) -> Self {
Ident {
sym: string.to_owned(),
span,
raw: true,
}
}
pub fn span(&self) -> Span {
self.span
}
pub fn set_span(&mut self, span: Span) {
self.span = span;
}
}
pub(crate) fn is_ident_start(c: char) -> bool {
c == '_' || unicode_ident::is_xid_start(c)
}
pub(crate) fn is_ident_continue(c: char) -> bool {
unicode_ident::is_xid_continue(c)
}
#[track_caller]
fn validate_ident(string: &str) {
if string.is_empty() {
panic!("Ident is not allowed to be empty; use Option<Ident>");
}
if string.bytes().all(|digit| b'0' <= digit && digit <= b'9') {
panic!("Ident cannot be a number; use Literal instead");
}
fn ident_ok(string: &str) -> bool {
let mut chars = string.chars();
let first = chars.next().unwrap();
if !is_ident_start(first) {
return false;
}
for ch in chars {
if !is_ident_continue(ch) {
return false;
}
}
true
}
if !ident_ok(string) {
panic!("{:?} is not a valid Ident", string);
}
}
#[track_caller]
fn validate_ident_raw(string: &str) {
validate_ident(string);
match string {
"_" | "super" | "self" | "Self" | "crate" => {
panic!("`r#{}` cannot be a raw identifier", string);
}
_ => {}
}
}
impl PartialEq for Ident {
fn eq(&self, other: &Ident) -> bool {
self.sym == other.sym && self.raw == other.raw
}
}
impl<T> PartialEq<T> for Ident
where
T: ?Sized + AsRef<str>,
{
fn eq(&self, other: &T) -> bool {
let other = other.as_ref();
if self.raw {
other.starts_with("r#") && self.sym == other[2..]
} else {
self.sym == other
}
}
}
impl Display for Ident {
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
if self.raw {
f.write_str("r#")?;
}
Display::fmt(&self.sym, f)
}
}
#[allow(clippy::missing_fields_in_debug)]
impl Debug for Ident {
// Ident(proc_macro), Ident(r#union)
#[cfg(not(span_locations))]
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
let mut debug = f.debug_tuple("Ident");
debug.field(&format_args!("{}", self));
debug.finish()
}
// Ident {
// sym: proc_macro,
// span: bytes(128..138)
// }
#[cfg(span_locations)]
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
let mut debug = f.debug_struct("Ident");
debug.field("sym", &format_args!("{}", self));
debug_span_field_if_nontrivial(&mut debug, self.span);
debug.finish()
}
}
#[derive(Clone)]
pub(crate) struct Literal {
repr: String,
span: Span,
}
macro_rules! suffixed_numbers {
($($name:ident => $kind:ident,)*) => ($(
pub fn $name(n: $kind) -> Literal {
Literal::_new(format!(concat!("{}", stringify!($kind)), n))
}
)*)
}
macro_rules! unsuffixed_numbers {
($($name:ident => $kind:ident,)*) => ($(
pub fn $name(n: $kind) -> Literal {
Literal::_new(n.to_string())
}
)*)
}
impl Literal {
pub(crate) fn _new(repr: String) -> Self {
Literal {
repr,
span: Span::call_site(),
}
}
pub(crate) unsafe fn from_str_unchecked(repr: &str) -> Self {
Literal::_new(repr.to_owned())
}
suffixed_numbers! {
u8_suffixed => u8,
u16_suffixed => u16,
u32_suffixed => u32,
u64_suffixed => u64,
u128_suffixed => u128,
usize_suffixed => usize,
i8_suffixed => i8,
i16_suffixed => i16,
i32_suffixed => i32,
i64_suffixed => i64,
i128_suffixed => i128,
isize_suffixed => isize,
f32_suffixed => f32,
f64_suffixed => f64,
}
unsuffixed_numbers! {
u8_unsuffixed => u8,
u16_unsuffixed => u16,
u32_unsuffixed => u32,
u64_unsuffixed => u64,
u128_unsuffixed => u128,
usize_unsuffixed => usize,
i8_unsuffixed => i8,
i16_unsuffixed => i16,
i32_unsuffixed => i32,
i64_unsuffixed => i64,
i128_unsuffixed => i128,
isize_unsuffixed => isize,
}
pub fn f32_unsuffixed(f: f32) -> Literal {
let mut s = f.to_string();
if !s.contains('.') {
s.push_str(".0");
}
Literal::_new(s)
}
pub fn f64_unsuffixed(f: f64) -> Literal {
let mut s = f.to_string();
if !s.contains('.') {
s.push_str(".0");
}
Literal::_new(s)
}
pub fn string(t: &str) -> Literal {
let mut repr = String::with_capacity(t.len() + 2);
repr.push('"');
let mut chars = t.chars();
while let Some(ch) = chars.next() {
if ch == '\0' {
repr.push_str(
if chars
.as_str()
.starts_with(|next| '0' <= next && next <= '7')
{
// circumvent clippy::octal_escapes lint
"\\x00"
} else {
"\\0"
},
);
} else if ch == '\'' {
// escape_debug turns this into "\'" which is unnecessary.
repr.push(ch);
} else {
repr.extend(ch.escape_debug());
}
}
repr.push('"');
Literal::_new(repr)
}
pub fn character(t: char) -> Literal {
let mut repr = String::new();
repr.push('\'');
if t == '"' {
// escape_debug turns this into '\"' which is unnecessary.
repr.push(t);
} else {
repr.extend(t.escape_debug());
}
repr.push('\'');
Literal::_new(repr)
}
pub fn byte_string(bytes: &[u8]) -> Literal {
let mut escaped = "b\"".to_string();
let mut bytes = bytes.iter();
while let Some(&b) = bytes.next() {
#[allow(clippy::match_overlapping_arm)]
match b {
b'\0' => escaped.push_str(match bytes.as_slice().first() {
// circumvent clippy::octal_escapes lint
Some(b'0'..=b'7') => r"\x00",
_ => r"\0",
}),
b'\t' => escaped.push_str(r"\t"),
b'\n' => escaped.push_str(r"\n"),
b'\r' => escaped.push_str(r"\r"),
b'"' => escaped.push_str("\\\""),
b'\\' => escaped.push_str("\\\\"),
b'\x20'..=b'\x7E' => escaped.push(b as char),
_ => {
let _ = write!(escaped, "\\x{:02X}", b);
}
}
}
escaped.push('"');
Literal::_new(escaped)
}
pub fn span(&self) -> Span {
self.span
}
pub fn set_span(&mut self, span: Span) {
self.span = span;
}
pub fn subspan<R: RangeBounds<usize>>(&self, range: R) -> Option<Span> {
#[cfg(not(span_locations))]
{
let _ = range;
None
}
#[cfg(span_locations)]
{
use core::ops::Bound;
let lo = match range.start_bound() {
Bound::Included(start) => {
let start = u32::try_from(*start).ok()?;
self.span.lo.checked_add(start)?
}
Bound::Excluded(start) => {
let start = u32::try_from(*start).ok()?;
self.span.lo.checked_add(start)?.checked_add(1)?
}
Bound::Unbounded => self.span.lo,
};
let hi = match range.end_bound() {
Bound::Included(end) => {
let end = u32::try_from(*end).ok()?;
self.span.lo.checked_add(end)?.checked_add(1)?
}
Bound::Excluded(end) => {
let end = u32::try_from(*end).ok()?;
self.span.lo.checked_add(end)?
}
Bound::Unbounded => self.span.hi,
};
if lo <= hi && hi <= self.span.hi {
Some(Span { lo, hi })
} else {
None
}
}
}
}
impl FromStr for Literal {
type Err = LexError;
fn from_str(repr: &str) -> Result<Self, Self::Err> {
let mut cursor = get_cursor(repr);
#[cfg(span_locations)]
let lo = cursor.off;
let negative = cursor.starts_with_char('-');
if negative {
cursor = cursor.advance(1);
if !cursor.starts_with_fn(|ch| ch.is_ascii_digit()) {
return Err(LexError::call_site());
}
}
if let Ok((rest, mut literal)) = parse::literal(cursor) {
if rest.is_empty() {
if negative {
literal.repr.insert(0, '-');
}
literal.span = Span {
#[cfg(span_locations)]
lo,
#[cfg(span_locations)]
hi: rest.off,
};
return Ok(literal);
}
}
Err(LexError::call_site())
}
}
impl Display for Literal {
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
Display::fmt(&self.repr, f)
}
}
impl Debug for Literal {
fn fmt(&self, fmt: &mut fmt::Formatter) -> fmt::Result {
let mut debug = fmt.debug_struct("Literal");
debug.field("lit", &format_args!("{}", self.repr));
debug_span_field_if_nontrivial(&mut debug, self.span);
debug.finish()
}
}