frame for gix repo rev explain (#427)

src/plumbing/main.rs

@@ -160,6 +160,9 @@ pub fn main() -> Result<()> {
             use git_repository as git;
             let repository = git::ThreadSafeRepository::discover(repository)?;
             match cmd {
+                repo::Subcommands::Revision { cmd } => match cmd {
+                    repo::revision::Subcommands::Explain { spec: _ } => todo!("describe spec"),
+                },
                 repo::Subcommands::Commit { cmd } => match cmd {
                     repo::commit::Subcommands::Describe {
                         annotated_tags,

src/plumbing/options.rs

@@ -343,7 +343,7 @@ pub mod repo {
     }
 
     #[derive(Debug, clap::Subcommand)]
-    #[clap(alias = "repo")]
+    #[clap(visible_alias = "repo")]
     pub enum Subcommands {
         /// Verify the integrity of the entire repository
         Verify {
@@ -375,6 +375,20 @@ pub mod repo {
             #[clap(subcommand)]
             cmd: exclude::Subcommands,
         },
+        /// Query and obtain information about revisions.
+        Revision {
+            #[clap(subcommand)]
+            cmd: revision::Subcommands,
+        },
+    }
+
+    pub mod revision {
+        #[derive(Debug, clap::Subcommand)]
+        #[clap(visible_alias = "rev")]
+        pub enum Subcommands {
+            /// Provide the revision specification like `@~1` to explain.
+            Explain { spec: std::ffi::OsString },
+        }
     }
 
     pub mod exclude {

src/porcelain/options.rs

@@ -84,7 +84,8 @@ pub enum ToolCommands {
     about = "Estimate hours worked based on a commit history", 
     long_about = "See https://github.com/kimmobrunfeldt/git-hours#how-it-works for details",
     version = clap::crate_version!(),
-    visible_alias = "h")
+    visible_alias = "h",
+    visible_alias = "hours")
 ]
 pub struct EstimateHours {
     /// The directory containing a '.git/' folder.