Add pad_with() as an alias to pad_char(). Fix README.

Author: keltia

README.md

@@ -23,6 +23,9 @@ fn main() {
 
     println!("{}", pad(s, 5));
     println!("{:?}", pad_char(s, 5, 'b'));
+    
+    // You can use pad_with() too now.
+    //println!("{:?}", pad_with(s, 5, 'b'));
 }
 ```
 ## crates.io
@@ -31,7 +34,7 @@ to your `Cargo.toml`:
 
 ``` toml
 [dependencies]
-leftpad-rs = "1.0.1"
+leftpad-rs = "1.1.0"
 ```
 then you can use it in your own crates.
 

src/lib.rs

@@ -34,6 +34,11 @@ pub mod leftpad_rs {
         Ok(format!("{}{}", f, s))
     }
 
+    /// Useful alias
+    pub fn pad_with(s: &str, n: usize, c: char) -> Result<String, &str> {
+        pad_char(s, n, c)
+    }
+    
     #[cfg(test)]
     mod tests {
         use super::*;
@@ -72,6 +77,26 @@ pub mod leftpad_rs {
         fn test_nopad_char() {
             assert_ne!(Ok("foobar".to_string()), pad_char("foo", 6, 'X'))
         }
+
+        #[rstest]
+        #[case(2, "foo")]
+        #[case(3, "foo")]
+        #[case(4, "Xfoo")]
+        #[case(5, "XXfoo")]
+        fn test_pad_with(#[case] n: usize, #[case] want: &str) {
+            assert_eq!(Ok(want.to_string()), pad_with("foo", n, 'X'));
+        }
+
+        #[test]
+        fn test_pad_with_0() {
+            assert_eq!(Err("invalid size"), pad_with("foo", 0, 'X'))
+        }
+
+        #[test]
+        fn test_nopad_with() {
+            assert_ne!(Ok("foobar".to_string()), pad_with("foo", 6, 'X'))
+        }
+
     }
 }