comparison rust/hg-core/src/matchers.rs @ 43611:27c25c0dc967

rust-matchers: remove default implementations for `Matcher` trait

We don't expect a whole lot of matchers to be defined, and this makes it more
obvious what a matcher does by reading its `impl Matcher for FooMatcher`.

This patch has the added benefit of fixing the `AlwaysMatcher`, its `matches`
function differs from the former default.

Differential Revision: https://phab.mercurial-scm.org/D7255

43610:11db74349b24

pub trait Matcher {
    /// Explicitly listed files
    fn file_set(&self) -> HashSet<&HgPath>;
    /// Returns whether `filename` is in `file_set`
    fn exact_match(&self, _filename: impl AsRef<HgPath>) -> bool {
        false
    }
    /// Returns whether `filename` is matched by this matcher
    fn matches(&self, _filename: impl AsRef<HgPath>) -> bool {
        false
    }
    /// Decides whether a directory should be visited based on whether it
    /// has potential matches in it or one of its subdirectories, and
    /// potentially lists which subdirectories of that directory should be
    /// visited. This is based on the match's primary, included, and excluded
    /// patterns.

    /// no files in this dir to investigate (or equivalently that if there are
    /// files to investigate in 'dir' that it will always return
    /// `VisitChildrenSet::This`).
    fn visit_children_set(
        &self,
        _directory: impl AsRef<HgPath>,
    ) -> VisitChildrenSet {
        VisitChildrenSet::This
    }
    /// Matcher will match everything and `files_set()` will be empty:
    /// optimization might be possible.
    fn matches_everything(&self) -> bool {
        false
    }
    /// Matcher will match exactly the files in `files_set()`: optimization
    /// might be possible.
    fn is_exact(&self) -> bool {
        false
    }
}

/// Matches everything.
#[derive(Debug)]
pub struct AlwaysMatcher;

impl Matcher for AlwaysMatcher {
    fn file_set(&self) -> HashSet<&HgPath> {
        HashSet::new()
    }

    fn visit_children_set(
        &self,
        _directory: impl AsRef<HgPath>,
    ) -> VisitChildrenSet {
        VisitChildrenSet::Recursive
    }
}

43611:27c25c0dc967

pub trait Matcher {
    /// Explicitly listed files
    fn file_set(&self) -> HashSet<&HgPath>;
    /// Returns whether `filename` is in `file_set`
    fn exact_match(&self, filename: impl AsRef<HgPath>) -> bool;
    /// Returns whether `filename` is matched by this matcher
    fn matches(&self, filename: impl AsRef<HgPath>) -> bool;
    /// Decides whether a directory should be visited based on whether it
    /// has potential matches in it or one of its subdirectories, and
    /// potentially lists which subdirectories of that directory should be
    /// visited. This is based on the match's primary, included, and excluded
    /// patterns.

    /// no files in this dir to investigate (or equivalently that if there are
    /// files to investigate in 'dir' that it will always return
    /// `VisitChildrenSet::This`).
    fn visit_children_set(
        &self,
        directory: impl AsRef<HgPath>,
    ) -> VisitChildrenSet;
    /// Matcher will match everything and `files_set()` will be empty:
    /// optimization might be possible.
    fn matches_everything(&self) -> bool;
    /// Matcher will match exactly the files in `files_set()`: optimization
    /// might be possible.
    fn is_exact(&self) -> bool;
}

/// Matches everything.
#[derive(Debug)]
pub struct AlwaysMatcher;

impl Matcher for AlwaysMatcher {
    fn file_set(&self) -> HashSet<&HgPath> {
        HashSet::new()
    }
    fn exact_match(&self, _filename: impl AsRef<HgPath>) -> bool {
        false
    }
    fn matches(&self, _filename: impl AsRef<HgPath>) -> bool {
        true
    }
    fn visit_children_set(
        &self,
        _directory: impl AsRef<HgPath>,
    ) -> VisitChildrenSet {
        VisitChildrenSet::Recursive
    }
    fn matches_everything(&self) -> bool {
        true
    }
    fn is_exact(&self) -> bool {
        false
    }
}