refactor(paroxysm): Explicitly macro imports, no more 'extern crate'

Removes all but one occurence of `extern crate`, to conform with Rust
2018.

The last one is necessary because Diesel is a giant jungle of
complicated macros re-exported from private crates, and the current
version makes it hard to import those directly instead.

Change-Id: Id14165a456d5c3ce6f7a4e0222c611640113eb11
Reviewed-on: https://cl.tvl.fyi/c/depot/+/1549
Tested-by: BuildkiteCI
Reviewed-by: kanepyork <rikingcoding@gmail.com>

fun/paroxysm/default.nix

@@ -7,5 +7,10 @@ pkgs.naersk.buildPackage {
   name = "paroxysm";
   version = "0.0.1";
   src = ./.;
-  buildInputs = [pkgs.openssl pkgs.pkgconfig pkgs.postgresql.lib];
+
+  buildInputs = with pkgs; [
+    openssl
+    pkgconfig
+    postgresql.lib
+  ];
 }

fun/paroxysm/src/cfg.rs

@@ -1,4 +1,5 @@
 use std::collections::HashSet;
+use serde_derive::Deserialize; // TODO(tazjin): move away from serde_derive
 
 #[derive(Deserialize)]
 pub struct Config {

fun/paroxysm/src/keyword.rs

@@ -2,6 +2,7 @@ use crate::models::{Entry, Keyword, NewEntry, NewKeyword};
 use diesel::pg::PgConnection;
 use diesel::prelude::*;
 use failure::Error;
+use failure::format_err;
 use std::borrow::Cow;
 
 /// Maximum number of times we'll follow a `see: ` pointer.

fun/paroxysm/src/main.rs

@@ -1,27 +1,16 @@
-extern crate irc;
+// TODO(tazjin): Upgrade to a Diesel version with public derive
-extern crate serde;
+// macros.
-#[macro_use]
+#[macro_use] extern crate diesel;
-extern crate serde_derive;
-#[macro_use]
-extern crate diesel;
-extern crate chrono;
-extern crate config;
-extern crate env_logger;
-#[macro_use]
-extern crate log;
-#[macro_use]
-extern crate failure;
-extern crate regex;
-#[macro_use]
-extern crate lazy_static;
-extern crate rand;
 
 use crate::cfg::Config;
 use crate::keyword::KeywordDetails;
 use diesel::pg::PgConnection;
 use diesel::r2d2::{ConnectionManager, Pool};
 use failure::Error;
+use failure::format_err;
 use irc::client::prelude::*;
+use lazy_static::lazy_static;
+use log::{debug, info, warn};
 use rand::rngs::ThreadRng;
 use rand::{thread_rng, Rng};
 use regex::{Captures, Regex};
@@ -275,6 +264,7 @@ impl App {
     }
 
     pub fn handle_privmsg(&mut self, from: &str, chan: &str, msg: &str) -> Result<(), Error> {
+        // TODO(tazjin): Move these to the top.
         lazy_static! {
             static ref LEARN_RE: Regex =
                 Regex::new(r#"^\?\?(?P<gen>!)?\s*(?P<subj>[^\[:]*):\s*(?P<val>.*)"#).unwrap();

fun/paroxysm/src/models.rs

@@ -1,5 +1,5 @@
-use crate::schema::{entries, keywords};
 use chrono::NaiveDateTime;
+use crate::schema::{entries, keywords};
 
 #[derive(Queryable)]
 pub struct Keyword {