Update Readme to be in line with crate docs.

README.md

@@ -1,16 +1,39 @@
 # Formatting and shortening byte slices as hexadecimal strings
 
 This crate provides wrappers for byte slices and lists of byte slices that implement the
-standard formatting traits and print the bytes as a hexadecimal string, eliding from the middle
-if the length would exceed the `precision` format parameter.
+standard formatting traits and print the bytes as a hexadecimal string. It respects the
+alignment, width and precision parameters and applies padding and shortening.
 
 ```rust
-use hex_fmt::{HexFmt, HexList};
+# use hex_fmt::{HexFmt, HexList};
+let bytes: &[u8] = &[0x0a, 0x1b, 0x2c, 0x3d, 0x4e, 0x5f];
 
-assert_eq!("090a0b", &format!("{}", HexFmt(&[9u8, 10, 11])));
-let nine_to_f = [9u8, 10, 11, 12, 13, 14, 15];
-assert_eq!("090..0f", &format!("{:.7}", HexFmt(&nine_to_f)));
-assert_eq!("090..e0f", &format!("{:.8}", HexFmt(&nine_to_f)));
-assert_eq!("090a..0e0f", &format!("{}", HexFmt(&nine_to_f)));
-assert_eq!("[4142, 4241]", &format!("{}", HexList(&[b"AB", b"BA"])));
+assert_eq!("0a1b..4e5f", &format!("{}", HexFmt(bytes)));
+
+// The default width is 10. Change it to apply padding or shortening.
+assert_eq!("0a..5f", &format!("{:6}", HexFmt(bytes)));
+assert_eq!("0a1b2c3d4e5f", &format!("{:12}", HexFmt(bytes)));
+assert_eq!("  0a1b2c3d4e5f  ", &format!("{:16}", HexFmt(bytes)));
+
+// The default alignment is centered. Use `<` or `>` to align left or right.
+assert_eq!("0a1b..", &format!("{:<6}", HexFmt(bytes)));
+assert_eq!("0a1b2c3d4e5f    ", &format!("{:<16}", HexFmt(bytes)));
+assert_eq!("..4e5f", &format!("{:>6}", HexFmt(bytes)));
+assert_eq!("    0a1b2c3d4e5f", &format!("{:>16}", HexFmt(bytes)));
+
+// Use e.g. `4.8` to set the minimum width to 4 and the maximum to 8.
+assert_eq!(" 12 ", &format!("{:4.8}", HexFmt([0x12])));
+assert_eq!("123456", &format!("{:4.8}", HexFmt([0x12, 0x34, 0x56])));
+assert_eq!("123..89a", &format!("{:4.8}", HexFmt([0x12, 0x34, 0x56, 0x78, 0x9a])));
+
+// If you prefer uppercase, use `X`.
+assert_eq!("0A1B..4E5F", &format!("{:X}", HexFmt(bytes)));
+
+// All of the above can be combined.
+assert_eq!("0A1B2C..", &format!("{:<4.8X}", HexFmt(bytes)));
+
+// With `HexList`, the parameters are applied to each entry.
+let list = &[[0x0a; 3], [0x1b; 3], [0x2c; 3]];
+assert_eq!("[0A.., 1B.., 2C..]", &format!("{:<4X}", HexList(list)));
 ```
+