diff --git a/src/settings/mod.rs b/src/settings/mod.rs
index e045a44..cb9599f 100644
--- a/src/settings/mod.rs
+++ b/src/settings/mod.rs
@@ -206,15 +206,17 @@ impl Settings {
                 }
             },
         };
+
         if settings.version > Self::get_ruleset_version() {
             error!("Ruleset version too high!");
-            return Err(std::io::Error::new(
+            Err(std::io::Error::new(
                 std::io::ErrorKind::InvalidData,
                 "Ruleset version too high!",
-            ));
+            ))
+        } else {
+            info!("Successfuly imported {}", path.display());
+            Ok(settings)
         }
-        info!("Successfuly imported {}", path.display());
-        Ok(settings)
     }
 
     /// Import settings from file path described by the argument `path`
@@ -228,13 +230,13 @@ impl Settings {
     /// ```no_run
     /// let s = lang_evolve_core::settings::Settings::from("settings.yml");
     /// ```
-    pub fn from<S>(s: S) -> Self
+    pub fn from<S>(s: S) -> std::io::Result<Self>
     where
         S: ToString,
     {
         let s = s.to_string();
         let path = std::path::Path::new(&s);
-        Self::import(&path).unwrap()
+        Self::import(&path)
     }
 
     /// Add a new rule to the current settings
diff --git a/src/settings/rule/mod.rs b/src/settings/rule/mod.rs
index 96a6926..f14fe36 100644
--- a/src/settings/rule/mod.rs
+++ b/src/settings/rule/mod.rs
@@ -1,14 +1,13 @@
 use std::collections::HashMap;
 
-use serde::{Deserialize, Serialize};
-
 use lazy_static::lazy_static;
+use serde::{Deserialize, Serialize};
 
 mod regex_wrapper;
 use regex_wrapper::Regex;
 
 lazy_static! {
-    static ref RE : Regex = Regex::new("%([A-Z])");
+    static ref RE: Regex = Regex::new("%([A-Z])");
 }
 
 /// Representation of a rule in LangEvolveRs
@@ -45,15 +44,9 @@ impl Rule {
         }
     }
 
-    fn detect_categories(&self) -> (u8, u8) {
-        let captures_from = match RE.captures(self.from.as_str()) {
-            None => 0 as u8,
-            Some(c) => c.len() as u8,
-        };
-        let captures_to = match RE.captures(&self.to) {
-            None => 0 as u8,
-            Some(c) => c.len() as u8,
-        };
+    pub fn detect_number_categories(&self) -> (u8, u8) {
+        let captures_from = self.from.to_string().matches('%').count() as u8;
+        let captures_to = self.to.matches('%').count() as u8;
         (captures_from, captures_to)
     }
 
@@ -67,7 +60,7 @@ impl Rule {
                         format!("%{}", category).as_str(),
                         format!("[{}]", content).as_str(),
                     )
-                    .as_str()
+                    .as_str(),
             );
         }
         rule
@@ -79,16 +72,14 @@ impl Rule {
         categories: &HashMap<String, String>,
     ) -> std::result::Result<Rule, String> {
         let mut rule = self.clone();
-        let (from_match, to_match) = self.detect_categories();
+        let (from_match, to_match) = self.detect_number_categories();
         // If there are only simple rewrites to make in the from String
         if from_match > 0 && to_match == 0 {
             rule = self.simple_rewrite(&categories);
         }
 
         // If there are equivalences between from and to
-        if from_match > 0 && to_match <= from_match && to_match > 0 {
-
-        }
+        if from_match > 0 && to_match <= from_match && to_match > 0 {}
 
         Ok(rule)
     }
@@ -105,10 +96,7 @@ impl Rule {
 impl From<String> for Rule {
     fn from(source: String) -> Self {
         let components: Vec<&str> = source.split_terminator('>').collect();
-        Self {
-            from: Regex::new(components[0]),
-            to: String::from(components[1]),
-        }
+        Rule::new(components[0], components[1])
     }
 }