Initial vendor packages

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

vendor/anstyle-parse/src/params.rs

@@ -0,0 +1,143 @@
+//! Fixed size parameters list with optional subparameters.
+
+use core::fmt::{self, Debug, Formatter};
+
+pub(crate) const MAX_PARAMS: usize = 32;
+
+#[derive(Default, Clone, PartialEq, Eq)]
+pub struct Params {
+    /// Number of subparameters for each parameter.
+    ///
+    /// For each entry in the `params` slice, this stores the length of the param as number of
+    /// subparams at the same index as the param in the `params` slice.
+    ///
+    /// At the subparam positions the length will always be `0`.
+    subparams: [u8; MAX_PARAMS],
+
+    /// All parameters and subparameters.
+    params: [u16; MAX_PARAMS],
+
+    /// Number of suparameters in the current parameter.
+    current_subparams: u8,
+
+    /// Total number of parameters and subparameters.
+    len: usize,
+}
+
+impl Params {
+    /// Returns the number of parameters.
+    #[inline]
+    pub fn len(&self) -> usize {
+        self.len
+    }
+
+    /// Returns `true` if there are no parameters present.
+    #[inline]
+    pub fn is_empty(&self) -> bool {
+        self.len == 0
+    }
+
+    /// Returns an iterator over all parameters and subparameters.
+    #[inline]
+    pub fn iter(&self) -> ParamsIter<'_> {
+        ParamsIter::new(self)
+    }
+
+    /// Returns `true` if there is no more space for additional parameters.
+    #[inline]
+    pub(crate) fn is_full(&self) -> bool {
+        self.len == MAX_PARAMS
+    }
+
+    /// Clear all parameters.
+    #[inline]
+    pub(crate) fn clear(&mut self) {
+        self.current_subparams = 0;
+        self.len = 0;
+    }
+
+    /// Add an additional parameter.
+    #[inline]
+    pub(crate) fn push(&mut self, item: u16) {
+        self.subparams[self.len - self.current_subparams as usize] = self.current_subparams + 1;
+        self.params[self.len] = item;
+        self.current_subparams = 0;
+        self.len += 1;
+    }
+
+    /// Add an additional subparameter to the current parameter.
+    #[inline]
+    pub(crate) fn extend(&mut self, item: u16) {
+        self.subparams[self.len - self.current_subparams as usize] = self.current_subparams + 1;
+        self.params[self.len] = item;
+        self.current_subparams += 1;
+        self.len += 1;
+    }
+}
+
+impl<'a> IntoIterator for &'a Params {
+    type IntoIter = ParamsIter<'a>;
+    type Item = &'a [u16];
+
+    fn into_iter(self) -> Self::IntoIter {
+        self.iter()
+    }
+}
+
+/// Immutable subparameter iterator.
+pub struct ParamsIter<'a> {
+    params: &'a Params,
+    index: usize,
+}
+
+impl<'a> ParamsIter<'a> {
+    fn new(params: &'a Params) -> Self {
+        Self { params, index: 0 }
+    }
+}
+
+impl<'a> Iterator for ParamsIter<'a> {
+    type Item = &'a [u16];
+
+    fn next(&mut self) -> Option<Self::Item> {
+        if self.index >= self.params.len() {
+            return None;
+        }
+
+        // Get all subparameters for the current parameter.
+        let num_subparams = self.params.subparams[self.index];
+        let param = &self.params.params[self.index..self.index + num_subparams as usize];
+
+        // Jump to the next parameter.
+        self.index += num_subparams as usize;
+
+        Some(param)
+    }
+
+    fn size_hint(&self) -> (usize, Option<usize>) {
+        let remaining = self.params.len() - self.index;
+        (remaining, Some(remaining))
+    }
+}
+
+impl Debug for Params {
+    fn fmt(&self, f: &mut Formatter<'_>) -> fmt::Result {
+        write!(f, "[")?;
+
+        for (i, param) in self.iter().enumerate() {
+            if i != 0 {
+                write!(f, ";")?;
+            }
+
+            for (i, subparam) in param.iter().enumerate() {
+                if i != 0 {
+                    write!(f, ":")?;
+                }
+
+                subparam.fmt(f)?;
+            }
+        }
+
+        write!(f, "]")
+    }
+}