# HG changeset patch
# User Antoine Cezar <antoine.cezar@octobus.net>
# Date 2020-06-05 06:46:35
# Node ID a46e36b824612be16b38a1c1cd11160c293d115b
# Parent  26114bd6ec60cb48b5dc52946c2f51a5fb698c7a

hg-core: add Operation interface for high-level hg operations

A distinction is made between operations and commands.
An operation is a high-level function of mercurial whereas a command is what is exposed by the cli.
A single command can use several operations to achieve its goal.

Differential Revision: https://phab.mercurial-scm.org/D8608

diff --git a/rust/hg-core/src/lib.rs b/rust/hg-core/src/lib.rs
--- a/rust/hg-core/src/lib.rs
+++ b/rust/hg-core/src/lib.rs
@@ -23,6 +23,7 @@ mod filepatterns;
 pub mod matchers;
 pub mod revlog;
 pub use revlog::*;
+pub mod operations;
 pub mod utils;
 
 // Remove this to see (potential) non-artificial compile failures. MacOS
diff --git a/rust/hg-core/src/operations/mod.rs b/rust/hg-core/src/operations/mod.rs
new file mode 100644
--- /dev/null
+++ b/rust/hg-core/src/operations/mod.rs
@@ -0,0 +1,9 @@
+/// An interface for high-level hg operations.
+///
+/// A distinction is made between operation and commands.
+/// An operation is what can be done whereas a command is what is exposed by
+/// the cli. A single command can use several operations to achieve its goal.
+pub trait Operation<T> {
+    type Error;
+    fn run(&self) -> Result<T, Self::Error>;
+}