From c2ea3bb1a59d27edb545d398c63c304218b84d24 Mon Sep 17 00:00:00 2001
From: Alex Helfet <alex.helfet@gmail.com>
Date: Sat, 30 Dec 2017 02:16:31 +0000
Subject: [PATCH] Wrote CustomDebug example for decode.

Closes #17.
---
 decode/README.md     | 16 +++++++++++++---
 test_type/src/lib.rs | 11 +++++++++++
 2 files changed, 24 insertions(+), 3 deletions(-)

diff --git a/decode/README.md b/decode/README.md
index e272ac8..91c9856 100644
--- a/decode/README.md
+++ b/decode/README.md
@@ -12,6 +12,11 @@ the `serde::Deserialize` and `std::fmt::Debug` traits.
 
 [typed]: https://docs.rs/framed/*/framed/typed/index.html
 
+Note: you must install [`jq`][jq] and have it on your path.
+[jq]: https://stedolan.github.io/jq/
+
+On Ubuntu you can install it with: `sudo apt install jq`.
+
 Here's an example. The main binary in crate `framed_test_type` writes
 a serialized and encoded `framed_test_type::Test` struct to stdout;
 first save that to a file:
@@ -79,8 +84,13 @@ OPTIONS:
             Csv, Debug, Json]
 ```
 
-Note: you must install [`jq`][jq] and have it on your path.
+To customize the output for your type, try creating a tuple struct
+with a custom Debug implementation. See `CustomDebug` in test_type for
+an example:
 
-On Ubuntu you can install it with: `sudo apt install jq`.
+```text
+~/framed-rs % export DECODE_TYPE_NAME=framed_test_type::CustomDebug;
+~/framed-rs % < test_data  bin/decode_typed
 
-[jq]: https://stedolan.github.io/jq/
+CustomDebug a=0x000000ff, b=0x2
+```
diff --git a/test_type/src/lib.rs b/test_type/src/lib.rs
index c7c9f8c..4f6c3e3 100644
--- a/test_type/src/lib.rs
+++ b/test_type/src/lib.rs
@@ -4,8 +4,19 @@ extern crate serde;
 #[macro_use]
 extern crate serde_derive;
 
+use std::fmt::{self, Debug, Formatter};
+
 #[derive(Debug, Deserialize, Serialize)]
 pub struct Test {
     pub a: u32,
     pub b: u16,
 }
+
+#[derive(Deserialize, Serialize)]
+pub struct CustomDebug(Test);
+
+impl Debug for CustomDebug {
+    fn fmt(&self, f: &mut Formatter) -> Result<(), fmt::Error> {
+        write!(f, "CustomDebug a=0x{:08x}, b=0x{:X}", self.0.a, self.0.b)
+    }
+}