result exercises

subject_source/src/errors.rs

@@ -1 +1,2 @@
 pub mod option;
+pub mod result;

subject_source/src/errors/result.rs

@@ -1,3 +1,4 @@
+/// Returns `true` if the result contains an `Err`
 pub fn is_err(res: &Result<i32, &str>) -> bool {
     match res {
         Err(_) => true,
@@ -5,10 +6,12 @@ pub fn is_err(res: &Result<i32, &str>) -> bool {
     }
 }
 
+/// Returns `true` if the result contains a `Ok`
 pub fn is_ok(res: &Result<i32, &str>) -> bool {
     !is_err(res)
 }
 
+/// Returns the wrapped `&str` if any, panic otherwise
 pub fn get_err_or_panic(res: Result<i32, &str>) -> &str {
     match res {
         Err(e) => e,
@@ -16,4 +19,19 @@ pub fn get_err_or_panic(res: Result<i32, &str>) -> &str {
     }
 }
 
-pub fn 
+/// Returns the wrapped `i32` if any, panic otherwise
+pub fn get_val_or_panic(res: Result<i32, &str>) -> i32 {
+    match res {
+        Ok(v) => v,
+        Err(_) => panic!("result was an error"),
+    }
+}
+
+/// Transforms `Ok` to `Some` and `Err` to `None`
+/// effectively discarding the `Err` wrapped value
+pub fn discard_err(res: Result<i32, &str>) -> Option<i32> {
+    match res {
+        Ok(v) => Some(v),
+        Err(_) => None,
+    }
+}