improve api

src/lib.rs

@@ -2,30 +2,23 @@
 extern crate log;
 
 use failure::{bail, Fallible};
+use serde::de::DeserializeOwned;
+use serde::Serialize;
 use std::collections::HashMap;
-use std::str::FromStr;
-use serde::{Serialize};
 use std::fmt::Debug;
-use std::path::{Path, PathBuf};
 use std::fs::File;
 use std::io::Read;
-use serde::de::DeserializeOwned;
+use std::path::{Path, PathBuf};
+use std::str::FromStr;
 
 pub const LOG_LEVELS: [&str; 5] = ["error", "warn", "info", "debug", "trace"];
 
 /// 3rd-party libraries that produce log spam - we set these to a fixed higher level
 /// to allow using e.g. TRACE without drowning our custom messages
-pub const SPAMMY_LIBS: [&str; 6] = [
-    "tokio_reactor",
-    "hyper",
-    "reqwest",
-    "mio",
-    "want",
-    "rumqtt",
-];
+pub const SPAMMY_LIBS: [&str; 6] = ["tokio_reactor", "hyper", "reqwest", "mio", "want", "rumqtt"];
 
 /// Implement this for the main config struct
-pub trait BoilerplateCfg {
+pub trait AppConfig: Sized + Serialize + DeserializeOwned + Debug + Default {
     type Init;
 
     /// Get log level
@@ -50,67 +43,64 @@ pub trait BoilerplateCfg {
     /// Configure the config object using args.
     /// Logging has already been inited and configured.
     fn configure<'a>(self, _clap: &clap::ArgMatches<'a>) -> Fallible<Self::Init>;
-}
-
-pub trait Boilerplate : BoilerplateCfg + Sized {
-    fn init(name: &str, cfg_file_name: &str, version : Option<String>) -> Fallible<Self::Init>;
-}
-
-fn read_file<P: AsRef<Path>>(path: P) -> Fallible<String> {
-    let path = path.as_ref();
-    let mut file = File::open(path)?;
-
-    let mut buf = String::new();
-    file.read_to_string(&mut buf)?;
-    Ok(buf)
-}
 
-impl<CFG : BoilerplateCfg + Serialize + DeserializeOwned + Debug + Default> Boilerplate for CFG {
     /// Initialize the app
-    fn init(name: &str, cfg_file_name: &str, version : Option<String>) -> Fallible<CFG::Init>
-    {
-        let version : String = version.unwrap_or_else(|| env!("CARGO_PKG_VERSION").into());
-        let clap =
-            clap::App::new(name)
-                .arg(clap::Arg::with_name("config")
-                    .short("c").long("config")
+    fn init(name: &str, cfg_file_name: &str, version: Option<String>) -> Fallible<Self::Init> {
+        let version: String = version.unwrap_or_else(|| env!("CARGO_PKG_VERSION").into());
+        let clap = clap::App::new(name)
+            .arg(
+                clap::Arg::with_name("config")
+                    .short("c")
+                    .long("config")
                     .value_name("FILE")
                     .help("Sets a custom config file (JSON5)")
-                    .takes_value(true))
-
-                .arg(clap::Arg::with_name("dump-config")
+                    .takes_value(true),
+            )
+            .arg(
+                clap::Arg::with_name("dump-config")
                     .long("dump-config")
                     .takes_value(false)
-                    .help("Print the loaded config struct"))
-
-                .arg(clap::Arg::with_name("default-config")
+                    .help("Print the loaded config struct"),
+            )
+            .arg(
+                clap::Arg::with_name("default-config")
                     .long("default-config")
                     .takes_value(false)
-                    .help("Print the default config JSON for reference (or to be piped to a file)"))
-
-                .arg(clap::Arg::with_name("verbose")
-                    .short("v").long("verbose").multiple(true)
-                    .help("Increase logging verbosity (repeat to increase)"))
-
-                .arg(clap::Arg::with_name("log-level")
+                    .help("Print the default config JSON for reference (or to be piped to a file)"),
+            )
+            .arg(
+                clap::Arg::with_name("verbose")
+                    .short("v")
+                    .long("verbose")
+                    .multiple(true)
+                    .help("Increase logging verbosity (repeat to increase)"),
+            )
+            .arg(
+                clap::Arg::with_name("log-level")
                     .long("log")
-                    .takes_value(true).value_name("LEVEL")
+                    .takes_value(true)
+                    .value_name("LEVEL")
                     .validator(|s| {
-                        if LOG_LEVELS.contains(&s.as_str()) { return Ok(()); }
+                        if LOG_LEVELS.contains(&s.as_str()) {
+                            return Ok(());
+                        }
                         Err(format!("Bad log level: {}", s))
                     })
-                    .help("Set logging verbosity (error,warning,info,debug,trace)"));
+                    .help("Set logging verbosity (error,warning,info,debug,trace)"),
+            );
 
         let clap = Self::add_args(clap);
 
         // this must be done after `add_args` or all hell breaks loose around lifetimes
-        let clap = clap
-            .version(version.as_str());
+        let clap = clap.version(version.as_str());
 
         let argv = clap.get_matches();
 
         if argv.is_present("default-config") {
-            println!("{}", serde_json::to_string_pretty(&CFG::default()).unwrap());
+            println!(
+                "{}",
+                serde_json::to_string_pretty(&Self::default()).unwrap()
+            );
             std::process::exit(0);
         }
 
@@ -121,15 +111,18 @@ impl<CFG : BoilerplateCfg + Serialize + DeserializeOwned + Debug + Default> Boil
 
         let filepath = PathBuf::from_str(cfg_file)?;
 
-        let config: CFG = if filepath.is_file() {
+        let config: Self = if filepath.is_file() {
             println!("Load config from \"{}\"", cfg_file);
 
             let buf = read_file(filepath)?;
             json5::from_str(&buf)?
         } else {
-            println!("Config file \"{}\" does not exist, using defaults.", cfg_file);
+            println!(
+                "Config file \"{}\" does not exist, using defaults.",
+                cfg_file
+            );
 
-            CFG::default()
+            Self::default()
         };
 
         let mut level = config.logging().as_str();
@@ -156,10 +149,7 @@ impl<CFG : BoilerplateCfg + Serialize + DeserializeOwned + Debug + Default> Boil
         /* Verbosity increased */
         if argv.is_present("verbose") {
             // bump verbosity if -v's are present
-            let pos = LOG_LEVELS
-                .iter()
-                .position(|x| x == &level)
-                .unwrap();
+            let pos = LOG_LEVELS.iter().position(|x| x == &level).unwrap();
 
             level = match LOG_LEVELS
                 .iter()
@@ -208,3 +198,12 @@ impl<CFG : BoilerplateCfg + Serialize + DeserializeOwned + Debug + Default> Boil
         config.configure(&argv)
     }
 }
+
+fn read_file<P: AsRef<Path>>(path: P) -> Fallible<String> {
+    let path = path.as_ref();
+    let mut file = File::open(path)?;
+
+    let mut buf = String::new();
+    file.read_to_string(&mut buf)?;
+    Ok(buf)
+}