use crate::{    file::{self, Commit, File},    graph::{self, Graph},};use git_object::borrowed; /// Accessimpl Graph {    pub fn commit_at(&self, pos: graph::Position) -> Commit<'_> {        let r = self.lookup_by_pos(pos);        r.file.commit_at(r.pos)    }     pub fn commit_by_id(&self, id: borrowed::Id<'_>) -> Option<Commit<'_>> {        let r = self.lookup_by_id(id)?;        Some(r.file.commit_at(r.file_pos))    }     pub fn id_at(&self, pos: graph::Position) -> borrowed::Id<'_> {        let r = self.lookup_by_pos(pos);        r.file.id_at(r.pos)    }     /// Iterate over commits in unsorted order.    pub fn iter_commits(&self) -> impl Iterator<Item = Commit<'_>> {        self.files.iter().flat_map(|file| file.iter_commits())    }     /// Iterate over commit IDs in unsorted order.    pub fn iter_ids(&self) -> impl Iterator<Item = borrowed::Id<'_>> {        self.files.iter().flat_map(|file| file.iter_ids())    }     pub fn lookup(&self, id: borrowed::Id<'_>) -> Option<graph::Position> {        Some(self.lookup_by_id(id)?.graph_pos)    }     pub fn num_commits(&self) -> u32 {        self.files.iter().map(|f| f.num_commits()).sum()    }} /// Access fundamentalsimpl Graph {    fn lookup_by_id(&self, id: borrowed::Id<'_>) -> Option<LookupByIdResult<'_>> {        let mut current_file_start = 0;        for file in &self.files {            if let Some(lex_pos) = file.lookup(id) {                return Some(LookupByIdResult {                    file,                    file_pos: lex_pos,                    graph_pos: graph::Position(current_file_start + lex_pos.0),                });            }            current_file_start += file.num_commits();        }        None    }     fn lookup_by_pos(&self, pos: graph::Position) -> LookupByPositionResult<'_> {        let mut remaining = pos.0;        for file in &self.files {            match remaining.checked_sub(file.num_commits()) {                Some(v) => remaining = v,                None => {                    return LookupByPositionResult {                        file,                        pos: file::Position(remaining),                    }                }            }        }        panic!("graph position too large: {}", pos.0);    }} #[derive(Clone)]struct LookupByIdResult<'a> {    pub file: &'a File,    pub graph_pos: graph::Position,    pub file_pos: file::Position,} #[derive(Clone)]struct LookupByPositionResult<'a> {    pub file: &'a File,    pub pos: file::Position,}