use bstr::BString; use crate::spec; /// The error returned by [`spec::parse()`][crate::spec::parse()].#[derive(Debug, thiserror::Error)]#[allow(missing_docs)]pub enum Error {    #[error("'~' needs to follow an anchor, like '@~'.")]    MissingTildeAnchor,    #[error("':' needs to be followed by either '/' and regex or the path to lookup in the HEAD tree.")]    MissingColonSuffix,    #[error("':/' must be followed by a regular expression.")]    EmptyTopLevelRegex,    #[error("Need one character after '/!', typically '-', but got {:?}", .regex)]    UnspecifiedRegexModifier { regex: BString },    #[error("Cannot peel to {:?} - unknown target.", .input)]    InvalidObject { input: BString },    #[error("Could not parse time {:?} for revlog lookup.", .input)]    Time {        input: BString,        source: Option<git_date::parse::Error>,    },    #[error("Sibling branches like 'upstream' or 'push' require a branch name with remote configuration, got {:?}", .name)]    SiblingBranchNeedsBranchName { name: BString },    #[error("Reflog entries require a ref name, got {:?}", .name)]    ReflogLookupNeedsRefName { name: BString },    #[error("A reference name must be followed by positive numbers in '@{{n}}', got {:?}", .nav)]    RefnameNeedsPositiveReflogEntries { nav: BString },    #[error("Negative or explicitly positive numbers are invalid here: {:?}", .input)]    SignedNumber { input: BString },    #[error("Could not parse number from {input:?}")]    InvalidNumber { input: BString },    #[error("Negative zeroes are invalid: {:?} - remove the '-'", .input)]    NegativeZero { input: BString },    #[error("The opening brace in {:?} was not matched", .input)]    UnclosedBracePair { input: BString },    #[error("Cannot set spec kind more than once. Previous value was {:?}, now it is {:?}", .prev_kind, .kind)]    KindSetTwice { prev_kind: spec::Kind, kind: spec::Kind },    #[error("The @ character is either standing alone or followed by `{{<content>}}`, got {:?}", .input)]    AtNeedsCurlyBrackets { input: BString },    #[error("A portion of the input could not be parsed: {:?}", .input)]    UnconsumedInput { input: BString },    #[error("The delegate didn't indicate success - check delegate for more information")]    Delegate,} ///pub mod delegate; /// A delegate to be informed about parse events, with methods split into categories.////// - **Anchors** - which revision to use as starting point for…/// - **Navigation** - where to go once from the initial revision/// - **Range** - to learn if the specification is for a single or multiple references, and how to combine them.pub trait Delegate: delegate::Revision + delegate::Navigate + delegate::Kind {    /// Called at the end of a successful parsing operation.    /// It can be used as a marker to finalize internal data structures.    ///    /// Note that it will not be called if there is unconsumed input.    fn done(&mut self);} pub(crate) mod function;