enforced ASCII validation on '--map' flag

src/ascii_manipulation.rs

@@ -17,7 +17,6 @@ fn to_ascii(char_map: String, image: DynamicImage) -> Vec<Vec<Ascii>> {
 
     for pixel in image.pixels() {
         let ch = char_map.as_bytes()[((get_color(pixel.2) as f32-1.0)/255f32 * l) as usize];
-        //fixme: might break with non-ASCII char_map
         str.push(Ascii::new(ch, pixel.2[0], pixel.2[1], pixel.2[2]));
 
         if pixel.0 == image.width()-1 {

src/cli.rs

@@ -92,6 +92,13 @@ impl Cli {
                 exit(1);
             }
         }
+
+        if let Some(map) = self.map.clone() {
+            if !map.is_ascii() {
+                error!("map can not contain non-ASCII characters!");
+                exit(1);
+            }
+        }
     }
 
     pub fn init(&self) {