disable 'as dependency' if backend does not support it

crates/pacdef_core/src/backend/actual/arch.rs

@@ -23,6 +23,8 @@ const SWITCHES_INSTALL: Switches = &["--sync"];
 const SWITCHES_MAKE_DEPENDENCY: Switches = &["--database", "--asdeps"];
 const SWITCHES_REMOVE: Switches = &["--remove", "--recursive"];
 
+const SUPPORTS_AS_DEPENDENCY: bool = true;
+
 impl Backend for Arch {
     impl_backend_constants!();
 

crates/pacdef_core/src/backend/actual/debian.rs

@@ -22,6 +22,8 @@ const SWITCHES_INSTALL: Switches = &["install"];
 const SWITCHES_MAKE_DEPENDENCY: Switches = &[]; // not needed
 const SWITCHES_REMOVE: Switches = &["remove"];
 
+const SUPPORTS_AS_DEPENDENCY: bool = true;
+
 impl Backend for Debian {
     impl_backend_constants!();
 

crates/pacdef_core/src/backend/actual/python.rs

@@ -22,6 +22,8 @@ const SWITCHES_INSTALL: Switches = &["install"];
 const SWITCHES_MAKE_DEPENDENCY: Switches = &[]; // not needed
 const SWITCHES_REMOVE: Switches = &["uninstall"];
 
+const SUPPORTS_AS_DEPENDENCY: bool = false;
+
 impl Backend for Python {
     impl_backend_constants!();
 

crates/pacdef_core/src/backend/actual/rust.rs

@@ -16,11 +16,14 @@ pub struct Rust {
 
 const BINARY: Text = "cargo";
 const SECTION: Text = "rust";
+
 const SWITCHES_INSTALL: Switches = &["install"];
 const SWITCHES_INFO: Switches = &["search", "--limit", "1"];
 const SWITCHES_MAKE_DEPENDENCY: Switches = &[];
 const SWITCHES_REMOVE: Switches = &["uninstall"];
 
+const SUPPORTS_AS_DEPENDENCY: bool = false;
+
 impl Backend for Rust {
     impl_backend_constants!();
 

crates/pacdef_core/src/backend/backend_trait.rs

@@ -120,6 +120,8 @@ pub trait Backend: Debug {
     }
 
     fn as_any_mut(&mut self) -> &mut dyn Any;
+
+    fn supports_as_dependency(&self) -> bool;
 }
 
 fn get_group_packages_map(

crates/pacdef_core/src/backend/macros.rs

@@ -53,5 +53,9 @@ macro_rules! impl_backend_constants {
         fn as_any_mut(&mut self) -> &mut dyn std::any::Any {
             self
         }
+
+        fn supports_as_dependency(&self) -> bool {
+            SUPPORTS_AS_DEPENDENCY
+        }
     };
 }