Add 'error-chain' to the main library

Use 'error-chain' here too. Seems like this will be a pretty useful
library.

Change the include in the 'meetup' `lib.rs` to allow us to export
`meetup::Error` instead of `meetup::errors::Error` to be consistent with
the error types of the other third-party libraries we're using.

4 files changed, 15 insertions, 5 deletions

diff --git a/src/build_rss.rs b/src/build_rss.rs
index 93430a1..0c31a43 100644
--- a/src/build_rss.rs
+++ b/src/build_rss.rs
@@ -1,4 +1,4 @@
-use std::error::Error;
+use errors::*;
 
 use meetup::client;
 use meetup_rss;
@@ -12,7 +12,7 @@ pub fn write_feed(
     end_date_range: String,
     radius: Option<String>,
     page: Option<String>,
-) -> Result<(), Box<Error>> {
+) -> Result<()> {
     let client = client::Client::new(token);
     let events = client.find_upcoming_events(
         latitude,
diff --git a/src/errors.rs b/src/errors.rs
new file mode 100644
index 0000000..d9e431b
--- /dev/null
+++ b/src/errors.rs
@@ -0,0 +1,6 @@
+error_chain! {
+    foreign_links {
+        Meetup(::meetup::Error);
+        Rss(::rss::Error);
+    }
+}
diff --git a/src/lib.rs b/src/lib.rs
index cc20fe5..6cfbd86 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -1,7 +1,10 @@
+#[macro_use]
+extern crate error_chain;
 extern crate rss;
 
 extern crate meetup;
 
 pub mod build_rss;
 
+mod errors;
 mod meetup_rss;
diff --git a/src/meetup_rss.rs b/src/meetup_rss.rs
index 7dd2b9e..d1d3f5f 100644
--- a/src/meetup_rss.rs
+++ b/src/meetup_rss.rs
@@ -1,10 +1,11 @@
-use rss::{self, Channel, ChannelBuilder, Item};
+use rss::{Channel, ChannelBuilder, Item};
 
 use std::io;
 
+use errors::*;
 use meetup::event::Event;
 
-pub fn generate(events: &Vec<Event>) -> Result<Channel, String> {
+pub fn generate(events: &Vec<Event>) -> Result<Channel> {
     let items: Vec<Item> = events.into_iter().map(|event| {
         let mut item = Item::default();
         item.set_title(event.name.clone());
@@ -24,7 +25,7 @@ pub fn generate(events: &Vec<Event>) -> Result<Channel, String> {
 }
 
 /// Writes the channel to standard output.
-pub fn write(channel: Channel) -> Result<(), rss::Error> {
+pub fn write(channel: Channel) -> Result<()> {
     let stdout = io::stdout();
     let handle = stdout.lock();