Add search --new to filter already installed modules

src/args.rs

@@ -136,6 +136,9 @@ pub struct Install {
 
 #[derive(Debug, StructOpt)]
 pub struct Search {
+    /// Only show modules that aren't installed yet
+    #[structopt(long="new")]
+    pub new: bool,
     /// The search query
     pub query: String,
 }

src/engine/mod.rs

@@ -181,14 +181,22 @@ impl<'a> Engine<'a> {
     }
 
     pub fn get(&self, name: &str) -> Result<&Module> {
+        if let Some(module) = self.get_opt(name)? {
+            Ok(module)
+        } else {
+            bail!("Module not found")
+        }
+    }
+
+    pub fn get_opt(&self, name: &str) -> Result<Option<&Module>> {
         if let Some(modules) = self.modules.get(name) {
             if modules.len() != 1 {
                 bail!("Ambiguous name: {:?}", modules)
             } else {
-                Ok(&modules[0])
+                Ok(Some(&modules[0]))
             }
         } else {
-            bail!("Module not found")
+            Ok(None)
         }
     }
 
@@ -201,11 +209,6 @@ impl<'a> Engine<'a> {
         modules
     }
 
-    pub fn is_installed(&self, canonical: &str) -> bool {
-        // TODO: maybe also compare version
-        self.modules.get(canonical).is_some()
-    }
-
     pub fn variants(&self) -> Vec<String> {
         self.modules.iter()
             .filter(|(_, values)| values.len() == 1)

src/registry.rs

@@ -97,11 +97,17 @@ pub fn run_search(engine: &Engine, search: &Search, config: &Config) -> Result<(
 
     for module in &modules {
         let canonical = module.canonical();
+        let installed = engine.get_opt(&canonical)?;
+
+        if search.new && installed.is_some() {
+            continue;
+        }
+
         println!("{} ({}) - {} downloads{}{}", canonical.green(),
                             module.latest.yellow(),
                             module.downloads.separated_string(),
                             (if module.featured { " [featured]" } else { "" }).cyan(),
-                            (if engine.is_installed(&canonical) { " [installed]" } else { "" }).green());
+                            (if installed.is_some() { " [installed]" } else { "" }).green());
         println!("\t{}", module.description);
     }