Feature Addition: Reverse Option

src/graph.rs

@@ -683,8 +683,8 @@ fn extract_branches(
 
 /// Traces back branches by following 1st commit parent,
 /// until a commit is reached that already has a trace.
-fn trace_branch<'repo>(
-    repository: &'repo Repository,
+fn trace_branch(
+    repository: &Repository,
     commits: &mut [CommitInfo],
     indices: &HashMap<Oid, usize>,
     branches: &mut [BranchInfo],

src/main.rs

@@ -52,6 +52,14 @@ fn from_args() -> Result<(), String> {
                  git-graph model             -> Show repo's current branching models\n    \
                  git-graph model <model>     -> Permanently set model <model> for this repo",
         )
+        .arg(
+            Arg::new("reverse")
+                .long("reverse")
+                .short('r')
+                .help("Reverse the order of commits.")
+                .required(false)
+                .num_args(0),
+        )
         .arg(
             Arg::new("path")
                 .long("path")
@@ -272,6 +280,8 @@ fn from_args() -> Result<(), String> {
 
     let include_remote = !matches.get_flag("local");
 
+    let reverse_commit_order = matches.get_flag("reverse");
+
     let svg = matches.get_flag("svg");
     let pager = !matches.get_flag("no-pager");
     let compact = !matches.get_flag("sparse");
@@ -281,6 +291,12 @@ fn from_args() -> Result<(), String> {
         .map(|s| Characters::from_str(s))
         .unwrap_or_else(|| Ok(Characters::thin()))?;
 
+    let style = if reverse_commit_order {
+        style.reverse()
+    } else {
+        style
+    };
+
     let model = get_model(
         &repository,
         matches.get_one::<String>("model").map(|s| &s[..]),
@@ -364,6 +380,7 @@ fn from_args() -> Result<(), String> {
     };
 
     let settings = Settings {
+        reverse_commit_order,
         debug,
         colored,
         compact,

src/print/unicode.rs

@@ -189,6 +189,11 @@ pub fn print_unicode(graph: &GitGraph, settings: &Settings) -> Result<UnicodeGra
         }
     }
 
+    if settings.reverse_commit_order {
+        text_lines.reverse();
+        grid.reverse();
+    }
+
     let lines = print_graph(&settings.characters, &grid, text_lines, settings.colored);
 
     Ok((lines.0, lines.1, index_map))
@@ -682,6 +687,10 @@ impl Grid {
             data: vec![initial; width * height],
         }
     }
+
+    pub fn reverse(&mut self) {
+        self.data.reverse();
+    }
     pub fn index(&self, x: usize, y: usize) -> usize {
         y * self.width + x
     }

src/settings.rs

@@ -29,6 +29,8 @@ pub enum BranchOrder {
 
 /// Top-level settings
 pub struct Settings {
+    /// Reverse the order of commits
+    pub reverse_commit_order: bool,
     /// Debug printing and drawing
     pub debug: bool,
     /// Compact text-based graph
@@ -336,4 +338,16 @@ impl Characters {
             chars: " *o|-+'..'||++<>".chars().collect(),
         }
     }
+
+    pub fn reverse(self) -> Self {
+        let mut chars = self.chars;
+
+        chars.swap(6, 8);
+        chars.swap(7, 9);
+        chars.swap(10, 11);
+        chars.swap(12, 13);
+        chars.swap(14, 15);
+
+        Characters { chars }
+    }
 }