1 files changed, 185 insertions, 0 deletions
diff --git a/third_party/rust/nom/src/internal.rs b/third_party/rust/nom/src/internal.rs
new file mode 100644
index 0000000000..401f98a906
--- /dev/null
+++ b/third_party/rust/nom/src/internal.rs
@@ -0,0 +1,185 @@
+//! Basic types to build the parsers
+
+use self::Needed::*;
+use crate::error::ErrorKind;
+
+/// Holds the result of parsing functions
+///
+/// It depends on I, the input type, O, the output type, and E, the error type (by default u32)
+///
+/// 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`.
+///
+pub type IResult<I, O, E=(I,ErrorKind)> = Result<(I, O), Err<E>>;
+
+/// Contains information on needed data if a parser returned `Incomplete`
+#[derive(Debug, PartialEq, Eq, Clone, Copy)]
+pub enum Needed {
+  /// needs more data, but we do not know how much
+  Unknown,
+  /// contains the required data size
+  Size(usize),
+}
+
+impl Needed {
+  /// 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(usize) -> usize>(self, f: F) -> Needed {
+    match self {
+      Unknown => Unknown,
+      Size(n) => Size(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)]
+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(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)),
+    }
+  }
+}
+
+#[cfg(feature = "std")]
+impl Err<(&[u8], ErrorKind)> {
+  /// Obtaining ownership
+  pub fn to_owned(self) -> Err<(Vec<u8>, ErrorKind)> {
+    self.map_input(ToOwned::to_owned)
+  }
+}
+
+#[cfg(feature = "std")]
+impl Err<(&str, ErrorKind)> {
+  /// automatically converts between errors if the underlying type supports it
+  pub fn to_owned(self) -> Err<(String, ErrorKind)> {
+    self.map_input(ToOwned::to_owned)
+  }
+}
+
+impl<E: Eq> Eq for Err<E> {}
+
+#[cfg(feature = "std")]
+use std::fmt;
+
+#[cfg(feature = "std")]
+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
+  }
+}
+
+#[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);
+    assert_size!(IResult<&str, &str, u32>, 40);
+    assert_size!(Needed, 16);
+    assert_size!(Err<u32>, 24);
+    assert_size!(ErrorKind, 1);
+  }
+
+  #[test]
+  fn err_map_test() {
+    let e = Err::Error(1);
+    assert_eq!(e.map(|v| v + 1), Err::Error(2));
+  }
+
+}