Initial vendor packages

Signed-off-by: Valentin Popov <valentin@popov.link>

1 files changed, 117 insertions, 0 deletions

diff --git a/vendor/miette/src/chain.rs b/vendor/miette/src/chain.rs
new file mode 100644
index 0000000..7a66383
--- /dev/null
+++ b/vendor/miette/src/chain.rs
@@ -0,0 +1,117 @@
+/*!
+Iterate over error `.source()` chains.
+
+NOTE: This module is taken wholesale from <https://crates.io/crates/eyre>.
+*/
+use std::error::Error as StdError;
+use std::vec;
+
+use ChainState::*;
+
+/// Iterator of a chain of source errors.
+///
+/// This type is the iterator returned by [`Report::chain`].
+///
+/// # Example
+///
+/// ```
+/// use miette::Report;
+/// use std::io;
+///
+/// pub fn underlying_io_error_kind(error: &Report) -> Option<io::ErrorKind> {
+///     for cause in error.chain() {
+///         if let Some(io_error) = cause.downcast_ref::<io::Error>() {
+///             return Some(io_error.kind());
+///         }
+///     }
+///     None
+/// }
+/// ```
+#[derive(Clone)]
+#[allow(missing_debug_implementations)]
+pub struct Chain<'a> {
+    state: crate::chain::ChainState<'a>,
+}
+
+#[derive(Clone)]
+pub(crate) enum ChainState<'a> {
+    Linked {
+        next: Option<&'a (dyn StdError + 'static)>,
+    },
+    Buffered {
+        rest: vec::IntoIter<&'a (dyn StdError + 'static)>,
+    },
+}
+
+impl<'a> Chain<'a> {
+    pub(crate) fn new(head: &'a (dyn StdError + 'static)) -> Self {
+        Chain {
+            state: ChainState::Linked { next: Some(head) },
+        }
+    }
+}
+
+impl<'a> Iterator for Chain<'a> {
+    type Item = &'a (dyn StdError + 'static);
+
+    fn next(&mut self) -> Option<Self::Item> {
+        match &mut self.state {
+            Linked { next } => {
+                let error = (*next)?;
+                *next = error.source();
+                Some(error)
+            }
+            Buffered { rest } => rest.next(),
+        }
+    }
+
+    fn size_hint(&self) -> (usize, Option<usize>) {
+        let len = self.len();
+        (len, Some(len))
+    }
+}
+
+impl DoubleEndedIterator for Chain<'_> {
+    fn next_back(&mut self) -> Option<Self::Item> {
+        match &mut self.state {
+            Linked { mut next } => {
+                let mut rest = Vec::new();
+                while let Some(cause) = next {
+                    next = cause.source();
+                    rest.push(cause);
+                }
+                let mut rest = rest.into_iter();
+                let last = rest.next_back();
+                self.state = Buffered { rest };
+                last
+            }
+            Buffered { rest } => rest.next_back(),
+        }
+    }
+}
+
+impl ExactSizeIterator for Chain<'_> {
+    fn len(&self) -> usize {
+        match &self.state {
+            Linked { mut next } => {
+                let mut len = 0;
+                while let Some(cause) = next {
+                    next = cause.source();
+                    len += 1;
+                }
+                len
+            }
+            Buffered { rest } => rest.len(),
+        }
+    }
+}
+
+impl Default for Chain<'_> {
+    fn default() -> Self {
+        Chain {
+            state: ChainState::Buffered {
+                rest: Vec::new().into_iter(),
+            },
+        }
+    }
+}