reorganize into separate crates

- taskchampion -- core implementation of a replica
 - taskchampion-cli -- command-line interface
 - taskchampion-sync-server -- server implementation (not much yet!)

cli/Cargo.toml

@@ -0,0 +1,10 @@
+[package]
+name = "taskchampion-cli"
+version = "0.1.0"
+authors = ["Dustin J. Mitchell <dustin@mozilla.com>"]
+edition = "2018"
+
+[dependencies]
+clap = "~2.33.0"
+uuid = { version = "0.8.1", features = ["serde", "v4"] }
+taskchampion = { path = "../taskchampion" }

cli/src/main.rs

@@ -0,0 +1,62 @@
+use clap::{App, Arg, SubCommand};
+use std::path::Path;
+use taskchampion::{taskstorage, Replica, Status, DB};
+use uuid::Uuid;
+
+fn main() {
+    let matches = App::new("Rask")
+        .version("0.1")
+        .author("Dustin J. Mitchell <dustin@v.igoro.us>")
+        .about("Replacement for TaskWarrior")
+        .subcommand(
+            SubCommand::with_name("add").about("adds a task").arg(
+                Arg::with_name("description")
+                    .help("task description")
+                    .required(true),
+            ),
+        )
+        .subcommand(SubCommand::with_name("list").about("lists tasks"))
+        .subcommand(SubCommand::with_name("pending").about("lists pending tasks"))
+        .subcommand(SubCommand::with_name("gc").about("run garbage collection"))
+        .get_matches();
+
+    let mut replica = Replica::new(
+        DB::new(Box::new(
+            taskstorage::KVStorage::new(Path::new("/tmp/tasks")).unwrap(),
+        ))
+        .into(),
+    );
+
+    match matches.subcommand() {
+        ("add", Some(matches)) => {
+            let uuid = Uuid::new_v4();
+            replica
+                .new_task(
+                    uuid,
+                    Status::Pending,
+                    matches.value_of("description").unwrap().into(),
+                )
+                .unwrap();
+        }
+        ("list", _) => {
+            for (uuid, task) in replica.all_tasks().unwrap() {
+                println!("{} - {:?}", uuid, task);
+            }
+        }
+        ("pending", _) => {
+            let working_set = replica.working_set().unwrap();
+            for i in 1..working_set.len() {
+                if let Some(ref task) = working_set[i] {
+                    println!("{}: {} - {:?}", i, task.get_uuid(), task);
+                }
+            }
+        }
+        ("gc", _) => {
+            replica.gc().unwrap();
+        }
+        ("", None) => {
+            unreachable!();
+        }
+        _ => unreachable!(),
+    };
+}