skeleton of merge functionality

src/lib.rs

@@ -37,11 +37,12 @@ use std::fmt::Display;
 use text::{Font, TextDirection};
 use tile::Tile;
 use variable::Variable;
+use std::num::ParseIntError;
 
 #[derive(Clone, Debug, Eq, PartialEq)]
 pub struct Instance {
     position: Position,
-    id: String, // item / ending.rs id
+    id: String, // item / ending id
 }
 
 #[derive(Clone, Debug, Eq, PartialEq)]
@@ -75,8 +76,8 @@ impl AnimationFrames for Vec<Image> {
 }
 
 #[inline]
-fn from_base36(str: &str) -> u64 {
-    u64::from_str_radix(str, 36).expect(&format!("Invalid base36 string: {}", str))
+fn from_base36(str: &str) -> Result<u64, ParseIntError> {
+    u64::from_str_radix(str, 36)
 }
 
 /// this doesn't work inside ToBase36 for some reason
@@ -171,11 +172,14 @@ fn new_unique_id(mut ids: Vec<String>) -> String {
     let mut new_id: u64 = 0;
 
     for id in ids {
-        if new_id != from_base36(&id) {
-            break;
-        }
+        let id= from_base36(&id);
+        if id.is_ok() {
+            if new_id != id.unwrap() {
+                break;
+            }
 
-        new_id += 1;
+            new_id += 1;
+        }
     }
 
     return to_base36(new_id);
@@ -209,9 +213,9 @@ mod test {
 
     #[test]
     fn test_from_base36() {
-        assert_eq!(from_base36("0"), 0);
-        assert_eq!(from_base36("0z"), 35);
-        assert_eq!(from_base36("11"), 37);
+        assert_eq!(from_base36("0").unwrap(), 0);
+        assert_eq!(from_base36("0z").unwrap(), 35);
+        assert_eq!(from_base36("11").unwrap(), 37);
     }
 
     #[test]