refactor(operation,link): port __toString to Display

Move __toString ports to std::fmt::Display: convert Link's inherent
to_string() and make OperationInterface require Display instead of a
to_string() method, with each operation implementing Display.

Also fix the operation __toString output to use show(false), matching
SolverOperation::__toString() (was show(true)).

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

6 files changed, 27 insertions, 19 deletions

diff --git a/crates/shirabe/src/dependency_resolver/operation/install_operation.rs b/crates/shirabe/src/dependency_resolver/operation/install_operation.rs
index 1331591..ca3286c 100644
--- a/crates/shirabe/src/dependency_resolver/operation/install_operation.rs
+++ b/crates/shirabe/src/dependency_resolver/operation/install_operation.rs
@@ -45,11 +45,13 @@ impl OperationInterface for InstallOperation {
         Self::format(self.package.clone(), lock)
     }
 
-    fn to_string(&self) -> String {
-        self.show(true)
-    }
-
     fn as_install_operation(&self) -> Option<&InstallOperation> {
         Some(self)
     }
 }
+
+impl std::fmt::Display for InstallOperation {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        write!(f, "{}", self.show(false))
+    }
+}
diff --git a/crates/shirabe/src/dependency_resolver/operation/mark_alias_installed_operation.rs b/crates/shirabe/src/dependency_resolver/operation/mark_alias_installed_operation.rs
index f5cb825..ab07b6a 100644
--- a/crates/shirabe/src/dependency_resolver/operation/mark_alias_installed_operation.rs
+++ b/crates/shirabe/src/dependency_resolver/operation/mark_alias_installed_operation.rs
@@ -44,8 +44,10 @@ impl OperationInterface for MarkAliasInstalledOperation {
                 .get_full_pretty_version(true, crate::package::DisplayMode::SourceRefIfDev),
         )
     }
+}
 
-    fn to_string(&self) -> String {
-        self.show(true)
+impl std::fmt::Display for MarkAliasInstalledOperation {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        write!(f, "{}", self.show(false))
     }
 }
diff --git a/crates/shirabe/src/dependency_resolver/operation/mark_alias_uninstalled_operation.rs b/crates/shirabe/src/dependency_resolver/operation/mark_alias_uninstalled_operation.rs
index f8314f5..1b107f0 100644
--- a/crates/shirabe/src/dependency_resolver/operation/mark_alias_uninstalled_operation.rs
+++ b/crates/shirabe/src/dependency_resolver/operation/mark_alias_uninstalled_operation.rs
@@ -44,8 +44,10 @@ impl OperationInterface for MarkAliasUninstalledOperation {
                 .get_full_pretty_version(true, crate::package::DisplayMode::SourceRefIfDev),
         )
     }
+}
 
-    fn to_string(&self) -> String {
-        self.show(true)
+impl std::fmt::Display for MarkAliasUninstalledOperation {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        write!(f, "{}", self.show(false))
     }
 }
diff --git a/crates/shirabe/src/dependency_resolver/operation/operation_interface.rs b/crates/shirabe/src/dependency_resolver/operation/operation_interface.rs
index 51b150c..30ed8eb 100644
--- a/crates/shirabe/src/dependency_resolver/operation/operation_interface.rs
+++ b/crates/shirabe/src/dependency_resolver/operation/operation_interface.rs
@@ -4,15 +4,13 @@ use crate::dependency_resolver::operation::InstallOperation;
 use crate::dependency_resolver::operation::UninstallOperation;
 use crate::dependency_resolver::operation::UpdateOperation;
 
-pub trait OperationInterface: std::fmt::Debug {
+pub trait OperationInterface: std::fmt::Display + std::fmt::Debug {
     fn as_any(&self) -> &dyn std::any::Any;
 
     fn get_operation_type(&self) -> String;
 
     fn show(&self, lock: bool) -> String;
 
-    fn to_string(&self) -> String;
-
     fn as_install_operation(&self) -> Option<&InstallOperation> {
         None
     }
diff --git a/crates/shirabe/src/dependency_resolver/operation/uninstall_operation.rs b/crates/shirabe/src/dependency_resolver/operation/uninstall_operation.rs
index 465297d..efb3610 100644
--- a/crates/shirabe/src/dependency_resolver/operation/uninstall_operation.rs
+++ b/crates/shirabe/src/dependency_resolver/operation/uninstall_operation.rs
@@ -44,11 +44,13 @@ impl OperationInterface for UninstallOperation {
         Self::format(self.package.clone(), lock)
     }
 
-    fn to_string(&self) -> String {
-        self.show(true)
-    }
-
     fn as_uninstall_operation(&self) -> Option<&UninstallOperation> {
         Some(self)
     }
 }
+
+impl std::fmt::Display for UninstallOperation {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        write!(f, "{}", self.show(false))
+    }
+}
diff --git a/crates/shirabe/src/dependency_resolver/operation/update_operation.rs b/crates/shirabe/src/dependency_resolver/operation/update_operation.rs
index 0bf3e35..76b1718 100644
--- a/crates/shirabe/src/dependency_resolver/operation/update_operation.rs
+++ b/crates/shirabe/src/dependency_resolver/operation/update_operation.rs
@@ -95,11 +95,13 @@ impl OperationInterface for UpdateOperation {
         )
     }
 
-    fn to_string(&self) -> String {
-        self.show(true)
-    }
-
     fn as_update_operation(&self) -> Option<&UpdateOperation> {
         Some(self)
     }
 }
+
+impl std::fmt::Display for UpdateOperation {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        write!(f, "{}", self.show(false))
+    }
+}