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-rw-r--r--third_party/rust/nom/src/internal.rs489
1 files changed, 489 insertions, 0 deletions
diff --git a/third_party/rust/nom/src/internal.rs b/third_party/rust/nom/src/internal.rs
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+//! Basic types to build the parsers
+
+use self::Needed::*;
+use crate::error::{self, ErrorKind};
+use crate::lib::std::fmt;
+use core::num::NonZeroUsize;
+
+/// Holds the result of parsing functions
+///
+/// It depends on the input type `I`, the output type `O`, and the error type `E`
+/// (by default `(I, nom::ErrorKind)`)
+///
+/// The `Ok` side is a pair containing the remainder of the input (the part of the data that
+/// was not parsed) and the produced value. The `Err` side contains an instance of `nom::Err`.
+///
+/// Outside of the parsing code, you can use the [Finish::finish] method to convert
+/// it to a more common result type
+pub type IResult<I, O, E = error::Error<I>> = Result<(I, O), Err<E>>;
+
+/// Helper trait to convert a parser's result to a more manageable type
+pub trait Finish<I, O, E> {
+ /// converts the parser's result to a type that is more consumable by error
+ /// management libraries. It keeps the same `Ok` branch, and merges `Err::Error`
+ /// and `Err::Failure` into the `Err` side.
+ ///
+ /// *warning*: if the result is `Err(Err::Incomplete(_))`, this method will panic.
+ /// - "complete" parsers: It will not be an issue, `Incomplete` is never used
+ /// - "streaming" parsers: `Incomplete` will be returned if there's not enough data
+ /// for the parser to decide, and you should gather more data before parsing again.
+ /// Once the parser returns either `Ok(_)`, `Err(Err::Error(_))` or `Err(Err::Failure(_))`,
+ /// you can get out of the parsing loop and call `finish()` on the parser's result
+ fn finish(self) -> Result<(I, O), E>;
+}
+
+impl<I, O, E> Finish<I, O, E> for IResult<I, O, E> {
+ fn finish(self) -> Result<(I, O), E> {
+ match self {
+ Ok(res) => Ok(res),
+ Err(Err::Error(e)) | Err(Err::Failure(e)) => Err(e),
+ Err(Err::Incomplete(_)) => {
+ panic!("Cannot call `finish()` on `Err(Err::Incomplete(_))`: this result means that the parser does not have enough data to decide, you should gather more data and try to reapply the parser instead")
+ }
+ }
+ }
+}
+
+/// Contains information on needed data if a parser returned `Incomplete`
+#[derive(Debug, PartialEq, Eq, Clone, Copy)]
+#[cfg_attr(nightly, warn(rustdoc::missing_doc_code_examples))]
+pub enum Needed {
+ /// Needs more data, but we do not know how much
+ Unknown,
+ /// Contains the required data size in bytes
+ Size(NonZeroUsize),
+}
+
+impl Needed {
+ /// Creates `Needed` instance, returns `Needed::Unknown` if the argument is zero
+ pub fn new(s: usize) -> Self {
+ match NonZeroUsize::new(s) {
+ Some(sz) => Needed::Size(sz),
+ None => Needed::Unknown,
+ }
+ }
+
+ /// Indicates if we know how many bytes we need
+ pub fn is_known(&self) -> bool {
+ *self != Unknown
+ }
+
+ /// Maps a `Needed` to `Needed` by applying a function to a contained `Size` value.
+ #[inline]
+ pub fn map<F: Fn(NonZeroUsize) -> usize>(self, f: F) -> Needed {
+ match self {
+ Unknown => Unknown,
+ Size(n) => Needed::new(f(n)),
+ }
+ }
+}
+
+/// The `Err` enum indicates the parser was not successful
+///
+/// It has three cases:
+///
+/// * `Incomplete` indicates that more data is needed to decide. The `Needed` enum
+/// can contain how many additional bytes are necessary. If you are sure your parser
+/// is working on full data, you can wrap your parser with the `complete` combinator
+/// to transform that case in `Error`
+/// * `Error` means some parser did not succeed, but another one might (as an example,
+/// when testing different branches of an `alt` combinator)
+/// * `Failure` indicates an unrecoverable error. As an example, if you recognize a prefix
+/// to decide on the next parser to apply, and that parser fails, you know there's no need
+/// to try other parsers, you were already in the right branch, so the data is invalid
+///
+#[derive(Debug, Clone, PartialEq)]
+#[cfg_attr(nightly, warn(rustdoc::missing_doc_code_examples))]
+pub enum Err<E> {
+ /// There was not enough data
+ Incomplete(Needed),
+ /// The parser had an error (recoverable)
+ Error(E),
+ /// The parser had an unrecoverable error: we got to the right
+ /// branch and we know other branches won't work, so backtrack
+ /// as fast as possible
+ Failure(E),
+}
+
+impl<E> Err<E> {
+ /// Tests if the result is Incomplete
+ pub fn is_incomplete(&self) -> bool {
+ if let Err::Incomplete(_) = self {
+ true
+ } else {
+ false
+ }
+ }
+
+ /// Applies the given function to the inner error
+ pub fn map<E2, F>(self, f: F) -> Err<E2>
+ where
+ F: FnOnce(E) -> E2,
+ {
+ match self {
+ Err::Incomplete(n) => Err::Incomplete(n),
+ Err::Failure(t) => Err::Failure(f(t)),
+ Err::Error(t) => Err::Error(f(t)),
+ }
+ }
+
+ /// Automatically converts between errors if the underlying type supports it
+ pub fn convert<F>(e: Err<F>) -> Self
+ where
+ E: From<F>,
+ {
+ e.map(crate::lib::std::convert::Into::into)
+ }
+}
+
+impl<T> Err<(T, ErrorKind)> {
+ /// Maps `Err<(T, ErrorKind)>` to `Err<(U, ErrorKind)>` with the given `F: T -> U`
+ pub fn map_input<U, F>(self, f: F) -> Err<(U, ErrorKind)>
+ where
+ F: FnOnce(T) -> U,
+ {
+ match self {
+ Err::Incomplete(n) => Err::Incomplete(n),
+ Err::Failure((input, k)) => Err::Failure((f(input), k)),
+ Err::Error((input, k)) => Err::Error((f(input), k)),
+ }
+ }
+}
+
+impl<T> Err<error::Error<T>> {
+ /// Maps `Err<error::Error<T>>` to `Err<error::Error<U>>` with the given `F: T -> U`
+ pub fn map_input<U, F>(self, f: F) -> Err<error::Error<U>>
+ where
+ F: FnOnce(T) -> U,
+ {
+ match self {
+ Err::Incomplete(n) => Err::Incomplete(n),
+ Err::Failure(error::Error { input, code }) => Err::Failure(error::Error {
+ input: f(input),
+ code,
+ }),
+ Err::Error(error::Error { input, code }) => Err::Error(error::Error {
+ input: f(input),
+ code,
+ }),
+ }
+ }
+}
+
+#[cfg(feature = "alloc")]
+use crate::lib::std::{borrow::ToOwned, string::String, vec::Vec};
+#[cfg(feature = "alloc")]
+impl Err<(&[u8], ErrorKind)> {
+ /// Obtaining ownership
+ #[cfg_attr(feature = "docsrs", doc(cfg(feature = "alloc")))]
+ pub fn to_owned(self) -> Err<(Vec<u8>, ErrorKind)> {
+ self.map_input(ToOwned::to_owned)
+ }
+}
+
+#[cfg(feature = "alloc")]
+impl Err<(&str, ErrorKind)> {
+ /// Obtaining ownership
+ #[cfg_attr(feature = "docsrs", doc(cfg(feature = "alloc")))]
+ pub fn to_owned(self) -> Err<(String, ErrorKind)> {
+ self.map_input(ToOwned::to_owned)
+ }
+}
+
+#[cfg(feature = "alloc")]
+impl Err<error::Error<&[u8]>> {
+ /// Obtaining ownership
+ #[cfg_attr(feature = "docsrs", doc(cfg(feature = "alloc")))]
+ pub fn to_owned(self) -> Err<error::Error<Vec<u8>>> {
+ self.map_input(ToOwned::to_owned)
+ }
+}
+
+#[cfg(feature = "alloc")]
+impl Err<error::Error<&str>> {
+ /// Obtaining ownership
+ #[cfg_attr(feature = "docsrs", doc(cfg(feature = "alloc")))]
+ pub fn to_owned(self) -> Err<error::Error<String>> {
+ self.map_input(ToOwned::to_owned)
+ }
+}
+
+impl<E: Eq> Eq for Err<E> {}
+
+impl<E> fmt::Display for Err<E>
+where
+ E: fmt::Debug,
+{
+ fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+ match self {
+ Err::Incomplete(Needed::Size(u)) => write!(f, "Parsing requires {} bytes/chars", u),
+ Err::Incomplete(Needed::Unknown) => write!(f, "Parsing requires more data"),
+ Err::Failure(c) => write!(f, "Parsing Failure: {:?}", c),
+ Err::Error(c) => write!(f, "Parsing Error: {:?}", c),
+ }
+ }
+}
+
+#[cfg(feature = "std")]
+use std::error::Error;
+
+#[cfg(feature = "std")]
+impl<E> Error for Err<E>
+where
+ E: fmt::Debug,
+{
+ fn source(&self) -> Option<&(dyn Error + 'static)> {
+ None // no underlying error
+ }
+}
+
+/// All nom parsers implement this trait
+pub trait Parser<I, O, E> {
+ /// A parser takes in input type, and returns a `Result` containing
+ /// either the remaining input and the output value, or an error
+ fn parse(&mut self, input: I) -> IResult<I, O, E>;
+
+ /// Maps a function over the result of a parser
+ fn map<G, O2>(self, g: G) -> Map<Self, G, O>
+ where
+ G: Fn(O) -> O2,
+ Self: core::marker::Sized,
+ {
+ Map {
+ f: self,
+ g,
+ phantom: core::marker::PhantomData,
+ }
+ }
+
+ /// Creates a second parser from the output of the first one, then apply over the rest of the input
+ fn flat_map<G, H, O2>(self, g: G) -> FlatMap<Self, G, O>
+ where
+ G: FnMut(O) -> H,
+ H: Parser<I, O2, E>,
+ Self: core::marker::Sized,
+ {
+ FlatMap {
+ f: self,
+ g,
+ phantom: core::marker::PhantomData,
+ }
+ }
+
+ /// Applies a second parser over the output of the first one
+ fn and_then<G, O2>(self, g: G) -> AndThen<Self, G, O>
+ where
+ G: Parser<O, O2, E>,
+ Self: core::marker::Sized,
+ {
+ AndThen {
+ f: self,
+ g,
+ phantom: core::marker::PhantomData,
+ }
+ }
+
+ /// Applies a second parser after the first one, return their results as a tuple
+ fn and<G, O2>(self, g: G) -> And<Self, G>
+ where
+ G: Parser<I, O2, E>,
+ Self: core::marker::Sized,
+ {
+ And { f: self, g }
+ }
+
+ /// Applies a second parser over the input if the first one failed
+ fn or<G>(self, g: G) -> Or<Self, G>
+ where
+ G: Parser<I, O, E>,
+ Self: core::marker::Sized,
+ {
+ Or { f: self, g }
+ }
+
+ /// automatically converts the parser's output and error values to another type, as long as they
+ /// implement the `From` trait
+ fn into<O2: From<O>, E2: From<E>>(self) -> Into<Self, O, O2, E, E2>
+ where
+ Self: core::marker::Sized,
+ {
+ Into {
+ f: self,
+ phantom_out1: core::marker::PhantomData,
+ phantom_err1: core::marker::PhantomData,
+ phantom_out2: core::marker::PhantomData,
+ phantom_err2: core::marker::PhantomData,
+ }
+ }
+}
+
+impl<'a, I, O, E, F> Parser<I, O, E> for F
+where
+ F: FnMut(I) -> IResult<I, O, E> + 'a,
+{
+ fn parse(&mut self, i: I) -> IResult<I, O, E> {
+ self(i)
+ }
+}
+
+#[cfg(feature = "alloc")]
+use alloc::boxed::Box;
+
+#[cfg(feature = "alloc")]
+impl<'a, I, O, E> Parser<I, O, E> for Box<dyn Parser<I, O, E> + 'a> {
+ fn parse(&mut self, input: I) -> IResult<I, O, E> {
+ (**self).parse(input)
+ }
+}
+
+/// Implementation of `Parser::map`
+#[cfg_attr(nightly, warn(rustdoc::missing_doc_code_examples))]
+pub struct Map<F, G, O1> {
+ f: F,
+ g: G,
+ phantom: core::marker::PhantomData<O1>,
+}
+
+impl<'a, I, O1, O2, E, F: Parser<I, O1, E>, G: Fn(O1) -> O2> Parser<I, O2, E> for Map<F, G, O1> {
+ fn parse(&mut self, i: I) -> IResult<I, O2, E> {
+ match self.f.parse(i) {
+ Err(e) => Err(e),
+ Ok((i, o)) => Ok((i, (self.g)(o))),
+ }
+ }
+}
+
+/// Implementation of `Parser::flat_map`
+#[cfg_attr(nightly, warn(rustdoc::missing_doc_code_examples))]
+pub struct FlatMap<F, G, O1> {
+ f: F,
+ g: G,
+ phantom: core::marker::PhantomData<O1>,
+}
+
+impl<'a, I, O1, O2, E, F: Parser<I, O1, E>, G: Fn(O1) -> H, H: Parser<I, O2, E>> Parser<I, O2, E>
+ for FlatMap<F, G, O1>
+{
+ fn parse(&mut self, i: I) -> IResult<I, O2, E> {
+ let (i, o1) = self.f.parse(i)?;
+ (self.g)(o1).parse(i)
+ }
+}
+
+/// Implementation of `Parser::and_then`
+#[cfg_attr(nightly, warn(rustdoc::missing_doc_code_examples))]
+pub struct AndThen<F, G, O1> {
+ f: F,
+ g: G,
+ phantom: core::marker::PhantomData<O1>,
+}
+
+impl<'a, I, O1, O2, E, F: Parser<I, O1, E>, G: Parser<O1, O2, E>> Parser<I, O2, E>
+ for AndThen<F, G, O1>
+{
+ fn parse(&mut self, i: I) -> IResult<I, O2, E> {
+ let (i, o1) = self.f.parse(i)?;
+ let (_, o2) = self.g.parse(o1)?;
+ Ok((i, o2))
+ }
+}
+
+/// Implementation of `Parser::and`
+#[cfg_attr(nightly, warn(rustdoc::missing_doc_code_examples))]
+pub struct And<F, G> {
+ f: F,
+ g: G,
+}
+
+impl<'a, I, O1, O2, E, F: Parser<I, O1, E>, G: Parser<I, O2, E>> Parser<I, (O1, O2), E>
+ for And<F, G>
+{
+ fn parse(&mut self, i: I) -> IResult<I, (O1, O2), E> {
+ let (i, o1) = self.f.parse(i)?;
+ let (i, o2) = self.g.parse(i)?;
+ Ok((i, (o1, o2)))
+ }
+}
+
+/// Implementation of `Parser::or`
+#[cfg_attr(nightly, warn(rustdoc::missing_doc_code_examples))]
+pub struct Or<F, G> {
+ f: F,
+ g: G,
+}
+
+impl<'a, I: Clone, O, E: crate::error::ParseError<I>, F: Parser<I, O, E>, G: Parser<I, O, E>>
+ Parser<I, O, E> for Or<F, G>
+{
+ fn parse(&mut self, i: I) -> IResult<I, O, E> {
+ match self.f.parse(i.clone()) {
+ Err(Err::Error(e1)) => match self.g.parse(i) {
+ Err(Err::Error(e2)) => Err(Err::Error(e1.or(e2))),
+ res => res,
+ },
+ res => res,
+ }
+ }
+}
+
+/// Implementation of `Parser::into`
+#[cfg_attr(nightly, warn(rustdoc::missing_doc_code_examples))]
+pub struct Into<F, O1, O2: From<O1>, E1, E2: From<E1>> {
+ f: F,
+ phantom_out1: core::marker::PhantomData<O1>,
+ phantom_err1: core::marker::PhantomData<E1>,
+ phantom_out2: core::marker::PhantomData<O2>,
+ phantom_err2: core::marker::PhantomData<E2>,
+}
+
+impl<
+ 'a,
+ I: Clone,
+ O1,
+ O2: From<O1>,
+ E1,
+ E2: crate::error::ParseError<I> + From<E1>,
+ F: Parser<I, O1, E1>,
+ > Parser<I, O2, E2> for Into<F, O1, O2, E1, E2>
+{
+ fn parse(&mut self, i: I) -> IResult<I, O2, E2> {
+ match self.f.parse(i) {
+ Ok((i, o)) => Ok((i, o.into())),
+ Err(Err::Error(e)) => Err(Err::Error(e.into())),
+ Err(Err::Failure(e)) => Err(Err::Failure(e.into())),
+ Err(Err::Incomplete(e)) => Err(Err::Incomplete(e)),
+ }
+ }
+}
+
+#[cfg(test)]
+mod tests {
+ use super::*;
+ use crate::error::ErrorKind;
+
+ #[doc(hidden)]
+ #[macro_export]
+ macro_rules! assert_size (
+ ($t:ty, $sz:expr) => (
+ assert_eq!(crate::lib::std::mem::size_of::<$t>(), $sz);
+ );
+ );
+
+ #[test]
+ #[cfg(target_pointer_width = "64")]
+ fn size_test() {
+ assert_size!(IResult<&[u8], &[u8], (&[u8], u32)>, 40);
+ //FIXME: since rust 1.65, this is now 32 bytes, likely thanks to https://github.com/rust-lang/rust/pull/94075
+ // deactivating that test for now because it'll have different values depending on the rust version
+ // assert_size!(IResult<&str, &str, u32>, 40);
+ assert_size!(Needed, 8);
+ assert_size!(Err<u32>, 16);
+ assert_size!(ErrorKind, 1);
+ }
+
+ #[test]
+ fn err_map_test() {
+ let e = Err::Error(1);
+ assert_eq!(e.map(|v| v + 1), Err::Error(2));
+ }
+}
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