fix(users/tazjin): rustfmt code with non-default settings r/3776

rustfmt only sometimes detects path-based nested config
files (probably some kind of race?), so my users folder uses a
separate formatting check for rustfmt to avoid flaky CI. Enough flakes
around already ...

Change-Id: Ifd862f9974f071b3a256643dd8e56c019116156a
Reviewed-on: https://cl.tvl.fyi/c/depot/+/5242
Reviewed-by: tazjin <tazjin@tvl.su>
Autosubmit: tazjin <tazjin@tvl.su>
Tested-by: BuildkiteCI

16 files changed, 348 insertions, 421 deletions

diff --git a/users/tazjin/default.nix b/users/tazjin/default.nix
new file mode 100644
index 0000000000..0c1baf14c8
--- /dev/null
+++ b/users/tazjin/default.nix
@@ -0,0 +1,16 @@
+# //users/tazjin-specific CI configuration.
+{ pkgs, ... }:
+
+let
+  rustfmt = pkgs.writeShellScript "rustfmt-tazjin" ''
+    ${pkgs.fd}/bin/fd -e rs | \
+      ${pkgs.ripgrep}/bin/rg 'users/tazjin' | \
+      xargs ${pkgs.rustfmt}/bin/rustfmt --check --config-path users/tazjin
+  '';
+
+in
+rustfmt.overrideAttrs (_: {
+  meta.ci.extraSteps.rustfmt = {
+    command = rustfmt;
+  };
+})
diff --git a/users/tazjin/finito/finito-core/src/lib.rs b/users/tazjin/finito/finito-core/src/lib.rs
index 517bfad2bc..aaec03a77b 100644
--- a/users/tazjin/finito/finito-core/src/lib.rs
+++ b/users/tazjin/finito/finito-core/src/lib.rs
@@ -38,8 +38,8 @@
 //!
 //!   * an event type representing all possible events in the machine
 //!
-//!   * an action type representing a description of all possible
-//!     side-effects of the machine
+//!   * an action type representing a description of all possible side-effects
+//!     of the machine
 //!
 //! Using the definition above we can now say that a transition in a
 //! state-machine, involving these three types, takes an initial state
@@ -92,14 +92,13 @@
 //!
 //!   * `finito`: Core components and classes of Finito
 //!
-//!   * `finito-in-mem`: In-memory implementation of state machines
-//!     that do not need to live longer than an application using
-//!     standard library concurrency primitives.
+//!   * `finito-in-mem`: In-memory implementation of state machines that do not
+//!     need to live longer than an application using standard library
+//!     concurrency primitives.
 //!
-//!   * `finito-postgres`: Postgres-backed, persistent implementation
-//!     of state machines that, well, do need to live longer. Uses
-//!     Postgres for concurrency synchronisation, so keep that in
-//!     mind.
+//!   * `finito-postgres`: Postgres-backed, persistent implementation of state
+//!     machines that, well, do need to live longer. Uses Postgres for
+//!     concurrency synchronisation, so keep that in mind.
 //!
 //! Which should cover most use-cases. Okay, enough prose, lets dive
 //! in.
@@ -110,8 +109,8 @@
 
 extern crate serde;
 
-use serde::Serialize;
 use serde::de::DeserializeOwned;
+use serde::Serialize;
 use std::fmt::Debug;
 use std::mem;
 
@@ -120,7 +119,10 @@ use std::mem;
 ///
 /// This trait is used to implement transition logic and to "tie the
 /// room together", with the room being our triplet of types.
-pub trait FSM where Self: Sized {
+pub trait FSM
+where
+    Self: Sized,
+{
     /// A human-readable string uniquely describing what this FSM
     /// models. This is used in log messages, database tables and
     /// various other things throughout Finito.
@@ -166,7 +168,7 @@ pub trait FSM where Self: Sized {
 
     /// `act` interprets and executes FSM actions. This is the only
     /// part of an FSM in which side-effects are allowed.
-    fn act(Self::Action, &Self::State) -> Result<Vec<Self::Event>, Self::Error>;
+    fn act(action: Self::Action, state: &Self::State) -> Result<Vec<Self::Event>, Self::Error>;
 }
 
 /// This function is the primary function used to advance a state
@@ -223,11 +225,13 @@ pub trait FSMBackend<S: 'static> {
     /// Insert a new state-machine into the backend's storage and
     /// return its newly allocated key.
     fn insert_machine<F>(&self, initial: F) -> Result<Self::Key, Self::Error>
-    where F: FSM + Serialize + DeserializeOwned;
+    where
+        F: FSM + Serialize + DeserializeOwned;
 
     /// Retrieve the current state of an FSM by its key.
     fn get_machine<F: FSM>(&self, key: Self::Key) -> Result<F, Self::Error>
-    where F: FSM + Serialize + DeserializeOwned;
+    where
+        F: FSM + Serialize + DeserializeOwned;
 
     /// Advance a state machine by applying an event and persisting it
     /// as well as any resulting actions.
@@ -236,8 +240,9 @@ pub trait FSMBackend<S: 'static> {
     /// on the backend used. Please consult the backend's
     /// documentation for details.
     fn advance<'a, F: FSM>(&'a self, key: Self::Key, event: F::Event) -> Result<F, Self::Error>
-    where F: FSM + Serialize + DeserializeOwned,
-          F::State: From<&'a S>,
-          F::Event: Serialize + DeserializeOwned,
-          F::Action: Serialize + DeserializeOwned;
+    where
+        F: FSM + Serialize + DeserializeOwned,
+        F::State: From<&'a S>,
+        F::Event: Serialize + DeserializeOwned,
+        F::Action: Serialize + DeserializeOwned;
 }
diff --git a/users/tazjin/finito/finito-door/src/lib.rs b/users/tazjin/finito/finito-door/src/lib.rs
index 68542c0bc4..441ab0e3d2 100644
--- a/users/tazjin/finito/finito-door/src/lib.rs
+++ b/users/tazjin/finito/finito-door/src/lib.rs
@@ -27,15 +27,15 @@
 //! The door can only be locked if it is closed. Oh, and it has a few
 //! extra features:
 //!
-//! * whenever the door's state changes, an IRC channel receives a
-//!   message about that
+//! * whenever the door's state changes, an IRC channel receives a message about
+//!   that
 //!
-//! * the door calls the police if the code is intered incorrectly more
-//!   than a specified number of times (mhm, lets say, three)
+//! * the door calls the police if the code is intered incorrectly more than a
+//!   specified number of times (mhm, lets say, three)
 //!
-//! * if the police is called the door can not be interacted with
-//!   anymore (and honestly, for the sake of this example, we don't
-//!   care how its functionality is restored)
+//! * if the police is called the door can not be interacted with anymore (and
+//!   honestly, for the sake of this example, we don't care how its
+//!   functionality is restored)
 //!
 //! ## The Door - Visualized
 //!
@@ -71,7 +71,8 @@
 //!
 //! Alright, enough foreplay, lets dive in!
 
-#[macro_use] extern crate serde_derive;
+#[macro_use]
+extern crate serde_derive;
 
 extern crate failure;
 extern crate finito;
@@ -292,11 +293,13 @@ mod tests {
     use finito::advance;
 
     fn test_fsm<S: FSM>(initial: S, events: Vec<S::Event>) -> (S, Vec<S::Action>) {
-        events.into_iter().fold((initial, vec![]), |(state, mut actions), event| {
-            let (new_state, mut new_actions) = advance(state, event);
-            actions.append(&mut new_actions);
-            (new_state, actions)
-        })
+        events
+            .into_iter()
+            .fold((initial, vec![]), |(state, mut actions), event| {
+                let (new_state, mut new_actions) = advance(state, event);
+                actions.append(&mut new_actions);
+                (new_state, actions)
+            })
     }
 
     #[test]
@@ -313,7 +316,10 @@ mod tests {
         ];
         let (final_state, actions) = test_fsm(initial, events);
 
-        assert_eq!(final_state, DoorState::Locked { code: 4567, attempts: 2 });
+        assert_eq!(final_state, DoorState::Locked {
+            code: 4567,
+            attempts: 2
+        });
         assert_eq!(actions, vec![
             DoorAction::NotifyIRC("door was closed".into()),
             DoorAction::NotifyIRC("door was opened".into()),
diff --git a/users/tazjin/finito/finito-postgres/src/error.rs b/users/tazjin/finito/finito-postgres/src/error.rs
index e130d18361..ed33775cd7 100644
--- a/users/tazjin/finito/finito-postgres/src/error.rs
+++ b/users/tazjin/finito/finito-postgres/src/error.rs
@@ -1,10 +1,9 @@
 //! This module defines error types and conversions for issue that can
 //! occur while dealing with persisted state machines.
 
-use std::result;
-use std::fmt;
-use uuid::Uuid;
 use std::error::Error as StdError;
+use std::{fmt, result};
+use uuid::Uuid;
 
 // errors to chain:
 use postgres::Error as PgError;
@@ -41,20 +40,15 @@ impl fmt::Display for Error {
     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
         use ErrorKind::*;
         let msg = match &self.kind {
-            Serialization(err) =>
-                format!("JSON serialization error: {}", err),
+            Serialization(err) => format!("JSON serialization error: {}", err),
 
-            Database(err) =>
-                format!("PostgreSQL error: {}", err),
+            Database(err) => format!("PostgreSQL error: {}", err),
 
-            DBPool(err) =>
-                format!("Database connection pool error: {}", err),
+            DBPool(err) => format!("Database connection pool error: {}", err),
 
-            FSMNotFound(id) =>
-                format!("FSM with ID {} not found", id),
+            FSMNotFound(id) => format!("FSM with ID {} not found", id),
 
-            ActionNotFound(id) =>
-                format!("Action with ID {} not found", id),
+            ActionNotFound(id) => format!("Action with ID {} not found", id),
         };
 
         match &self.context {
@@ -66,7 +60,7 @@ impl fmt::Display for Error {
 
 impl StdError for Error {}
 
-impl <E: Into<ErrorKind>> From<E> for Error {
+impl<E: Into<ErrorKind>> From<E> for Error {
     fn from(err: E) -> Error {
         Error {
             kind: err.into(),
@@ -99,11 +93,11 @@ pub trait ResultExt<T> {
     fn context<C: fmt::Display>(self, ctx: C) -> Result<T>;
 }
 
-impl <T, E: Into<Error>> ResultExt<T> for result::Result<T, E> {
+impl<T, E: Into<Error>> ResultExt<T> for result::Result<T, E> {
     fn context<C: fmt::Display>(self, ctx: C) -> Result<T> {
         self.map_err(|err| Error {
             context: Some(format!("{}", ctx)),
-            .. err.into()
+            ..err.into()
         })
     }
 }
diff --git a/users/tazjin/finito/finito-postgres/src/lib.rs b/users/tazjin/finito/finito-postgres/src/lib.rs
index ae147f751f..ea63cc9dfd 100644
--- a/users/tazjin/finito/finito-postgres/src/lib.rs
+++ b/users/tazjin/finito/finito-postgres/src/lib.rs
@@ -4,8 +4,10 @@
 //!
 //! TODO: events & actions should have `SERIAL` keys
 
-#[macro_use] extern crate postgres;
-#[macro_use] extern crate postgres_derive;
+#[macro_use]
+extern crate postgres;
+#[macro_use]
+extern crate postgres_derive;
 
 extern crate chrono;
 extern crate finito;
@@ -14,23 +16,25 @@ extern crate serde;
 extern crate serde_json;
 extern crate uuid;
 
-#[cfg(test)] mod tests;
-#[cfg(test)] extern crate finito_door;
+#[cfg(test)]
+mod tests;
+#[cfg(test)]
+extern crate finito_door;
 
 mod error;
-pub use error::{Result, Error, ErrorKind};
+pub use error::{Error, ErrorKind, Result};
 
 use chrono::prelude::{DateTime, Utc};
 use error::ResultExt;
-use finito::{FSM, FSMBackend};
+use finito::{FSMBackend, FSM};
 use postgres::transaction::Transaction;
 use postgres::GenericConnection;
-use serde::Serialize;
+use r2d2_postgres::{r2d2, PostgresConnectionManager};
 use serde::de::DeserializeOwned;
+use serde::Serialize;
 use serde_json::Value;
 use std::marker::PhantomData;
 use uuid::Uuid;
-use r2d2_postgres::{r2d2, PostgresConnectionManager};
 
 type DBPool = r2d2::Pool<PostgresConnectionManager>;
 type DBConn = r2d2::PooledConnection<PostgresConnectionManager>;
@@ -112,15 +116,13 @@ pub struct FinitoPostgres<S> {
     db_pool: DBPool,
 }
 
-impl <S> FinitoPostgres<S> {
+impl<S> FinitoPostgres<S> {
     pub fn new(state: S, db_pool: DBPool, _pool_size: usize) -> Self {
-        FinitoPostgres {
-            state, db_pool,
-        }
+        FinitoPostgres { state, db_pool }
     }
 }
 
-impl <State: 'static> FSMBackend<State> for FinitoPostgres<State> {
+impl<State: 'static> FSMBackend<State> for FinitoPostgres<State> {
     type Key = Uuid;
     type Error = Error;
 
@@ -134,10 +136,11 @@ impl <State: 'static> FSMBackend<State> for FinitoPostgres<State> {
         let fsm = S::FSM_NAME.to_string();
         let state = serde_json::to_value(initial).context("failed to serialise FSM")?;
 
-        self.conn()?.execute(query, &[&id, &fsm, &state]).context("failed to insert FSM")?;
+        self.conn()?
+            .execute(query, &[&id, &fsm, &state])
+            .context("failed to insert FSM")?;
 
         return Ok(id);
-
     }
 
     fn get_machine<S: FSM + DeserializeOwned>(&self, key: Uuid) -> Result<S> {
@@ -156,10 +159,12 @@ impl <State: 'static> FSMBackend<State> for FinitoPostgres<State> {
     /// processing is finished as running actions may result in additional
     /// transitions.
     fn advance<'a, S>(&'a self, key: Uuid, event: S::Event) -> Result<S>
-    where S: FSM + Serialize + DeserializeOwned,
-          S::State: From<&'a State>,
-          S::Event: Serialize + DeserializeOwned,
-          S::Action: Serialize + DeserializeOwned {
+    where
+        S: FSM + Serialize + DeserializeOwned,
+        S::State: From<&'a State>,
+        S::Event: Serialize + DeserializeOwned,
+        S::Action: Serialize + DeserializeOwned,
+    {
         let conn = self.conn()?;
         let tx = conn.transaction().context("could not begin transaction")?;
         let state = get_machine_internal(&tx, key, true)?;
@@ -187,16 +192,18 @@ impl <State: 'static> FSMBackend<State> for FinitoPostgres<State> {
     }
 }
 
-impl <State: 'static> FinitoPostgres<State> {
+impl<State: 'static> FinitoPostgres<State> {
     /// Execute several actions at the same time, each in a separate
     /// thread. Note that actions returning further events, causing
     /// further transitions, returning further actions and so on will
     /// potentially cause multiple threads to get created.
-    fn run_actions<'a, S>(&'a self, fsm_id: Uuid, action_ids: Vec<Uuid>) where
+    fn run_actions<'a, S>(&'a self, fsm_id: Uuid, action_ids: Vec<Uuid>)
+    where
         S: FSM + Serialize + DeserializeOwned,
         S::Event: Serialize + DeserializeOwned,
         S::Action: Serialize + DeserializeOwned,
-        S::State: From<&'a State> {
+        S::State: From<&'a State>,
+    {
         let state: S::State = (&self.state).into();
         let conn = self.conn().expect("TODO");
 
@@ -214,17 +221,19 @@ impl <State: 'static> FinitoPostgres<State> {
 
     /// Retrieve a single connection from the database connection pool.
     fn conn(&self) -> Result<DBConn> {
-        self.db_pool.get().context("failed to retrieve connection from pool")
+        self.db_pool
+            .get()
+            .context("failed to retrieve connection from pool")
     }
 }
 
-
-
 /// Insert a single state-machine into the database and return its
 /// newly allocated, random UUID.
-pub fn insert_machine<C, S>(conn: &C, initial: S) -> Result<Uuid> where
+pub fn insert_machine<C, S>(conn: &C, initial: S) -> Result<Uuid>
+where
     C: GenericConnection,
-    S: FSM + Serialize {
+    S: FSM + Serialize,
+{
     let query = r#"
       INSERT INTO machines (id, fsm, state)
       VALUES ($1, $2, $3)
@@ -240,13 +249,12 @@ pub fn insert_machine<C, S>(conn: &C, initial: S) -> Result<Uuid> where
 }
 
 /// Insert a single event into the database and return its UUID.
-fn insert_event<C, S>(conn: &C,
-                      fsm_id: Uuid,
-                      event: &S::Event) -> Result<Uuid>
+fn insert_event<C, S>(conn: &C, fsm_id: Uuid, event: &S::Event) -> Result<Uuid>
 where
     C: GenericConnection,
     S: FSM,
-    S::Event: Serialize {
+    S::Event: Serialize,
+{
     let query = r#"
       INSERT INTO events (id, fsm, fsm_id, event)
       VALUES ($1, $2, $3, $4)
@@ -254,21 +262,19 @@ where
 
     let id = Uuid::new_v4();
     let fsm = S::FSM_NAME.to_string();
-    let event_value = serde_json::to_value(event)
-        .context("failed to serialize event")?;
+    let event_value = serde_json::to_value(event).context("failed to serialize event")?;
 
     conn.execute(query, &[&id, &fsm, &fsm_id, &event_value])?;
-    return Ok(id)
+    return Ok(id);
 }
 
 /// Insert a single action into the database and return its UUID.
-fn insert_action<C, S>(conn: &C,
-                       fsm_id: Uuid,
-                       event_id: Uuid,
-                       action: &S::Action) -> Result<Uuid> where
+fn insert_action<C, S>(conn: &C, fsm_id: Uuid, event_id: Uuid, action: &S::Action) -> Result<Uuid>
+where
     C: GenericConnection,
     S: FSM,
-    S::Action: Serialize {
+    S::Action: Serialize,
+{
     let query = r#"
       INSERT INTO actions (id, fsm, fsm_id, event_id, content, status)
       VALUES ($1, $2, $3, $4, $5, $6)
@@ -276,23 +282,26 @@ fn insert_action<C, S>(conn: &C,
 
     let id = Uuid::new_v4();
     let fsm = S::FSM_NAME.to_string();
-    let action_value = serde_json::to_value(action)
-        .context("failed to serialize action")?;
+    let action_value = serde_json::to_value(action).context("failed to serialize action")?;
 
-    conn.execute(
-        query,
-        &[&id, &fsm, &fsm_id, &event_id, &action_value, &ActionStatus::Pending]
-    )?;
+    conn.execute(query, &[
+        &id,
+        &fsm,
+        &fsm_id,
+        &event_id,
+        &action_value,
+        &ActionStatus::Pending,
+    ])?;
 
-    return Ok(id)
+    return Ok(id);
 }
 
 /// Update the state of a specified machine.
-fn update_state<C, S>(conn: &C,
-                      fsm_id: Uuid,
-                      state: &S) -> Result<()> where
+fn update_state<C, S>(conn: &C, fsm_id: Uuid, state: &S) -> Result<()>
+where
     C: GenericConnection,
-    S: FSM + Serialize {
+    S: FSM + Serialize,
+{
     let query = r#"
       UPDATE machines SET state = $1 WHERE id = $2
     "#;
@@ -312,23 +321,28 @@ fn update_state<C, S>(conn: &C,
 fn alter_for_update(alter: bool, query: &str) -> String {
     match alter {
         false => query.to_string(),
-        true  => format!("{} FOR UPDATE", query),
+        true => format!("{} FOR UPDATE", query),
     }
 }
 
 /// Retrieve the current state of a state machine from the database,
 /// optionally locking the machine state for the duration of some
 /// enclosing transaction.
-fn get_machine_internal<C, S>(conn: &C,
-                              id: Uuid,
-                              for_update: bool) -> Result<S> where
+fn get_machine_internal<C, S>(conn: &C, id: Uuid, for_update: bool) -> Result<S>
+where
     C: GenericConnection,
-    S: FSM + DeserializeOwned {
-    let query = alter_for_update(for_update, r#"
+    S: FSM + DeserializeOwned,
+{
+    let query = alter_for_update(
+        for_update,
+        r#"
       SELECT state FROM machines WHERE id = $1
-    "#);
+    "#,
+    );
 
-    let rows = conn.query(&query, &[&id]).context("failed to retrieve FSM")?;
+    let rows = conn
+        .query(&query, &[&id])
+        .context("failed to retrieve FSM")?;
 
     if let Some(row) = rows.into_iter().next() {
         Ok(serde_json::from_value(row.get(0)).context("failed to deserialize FSM")?)
@@ -339,20 +353,25 @@ fn get_machine_internal<C, S>(conn: &C,
 
 /// Retrieve an action from the database, optionally locking it for
 /// the duration of some enclosing transaction.
-fn get_action<C, S>(conn: &C, id: Uuid) -> Result<(ActionStatus, S::Action)> where
+fn get_action<C, S>(conn: &C, id: Uuid) -> Result<(ActionStatus, S::Action)>
+where
     C: GenericConnection,
     S: FSM,
-    S::Action: DeserializeOwned {
-    let query = alter_for_update(true, r#"
+    S::Action: DeserializeOwned,
+{
+    let query = alter_for_update(
+        true,
+        r#"
       SELECT status, content FROM actions
       WHERE id = $1 AND fsm = $2
-    "#);
+    "#,
+    );
 
     let rows = conn.query(&query, &[&id, &S::FSM_NAME])?;
 
     if let Some(row) = rows.into_iter().next() {
-        let action = serde_json::from_value(row.get(1))
-            .context("failed to deserialize FSM action")?;
+        let action =
+            serde_json::from_value(row.get(1)).context("failed to deserialize FSM action")?;
         Ok((row.get(0), action))
     } else {
         Err(ErrorKind::ActionNotFound(id).into())
@@ -360,13 +379,17 @@ fn get_action<C, S>(conn: &C, id: Uuid) -> Result<(ActionStatus, S::Action)> whe
 }
 
 /// Update the status of an action after an attempt to run it.
-fn update_action_status<C, S>(conn: &C,
-                              id: Uuid,
-                              status: ActionStatus,
-                              error: Option<String>,
-                              _fsm: PhantomData<S>) -> Result<()> where
+fn update_action_status<C, S>(
+    conn: &C,
+    id: Uuid,
+    status: ActionStatus,
+    error: Option<String>,
+    _fsm: PhantomData<S>,
+) -> Result<()>
+where
     C: GenericConnection,
-    S: FSM {
+    S: FSM,
+{
     let query = r#"
       UPDATE actions SET status = $1, error = $2
       WHERE id = $3 AND fsm = $4
@@ -389,10 +412,16 @@ fn update_action_status<C, S>(conn: &C,
 /// panic), the error will be persisted. Should it fail by panicking
 /// (which developers should never do explicitly in action
 /// interpreters) its status will not be changed.
-fn run_action<S>(tx: Transaction, id: Uuid, state: &S::State, _fsm: PhantomData<S>)
-                 -> Result<Vec<S::Event>> where
+fn run_action<S>(
+    tx: Transaction,
+    id: Uuid,
+    state: &S::State,
+    _fsm: PhantomData<S>,
+) -> Result<Vec<S::Event>>
+where
     S: FSM,
-    S::Action: DeserializeOwned {
+    S::Action: DeserializeOwned,
+{
     let (status, action) = get_action::<Transaction, S>(&tx, id)?;
 
     let result = match status {
@@ -401,29 +430,25 @@ fn run_action<S>(tx: Transaction, id: Uuid, state: &S::State, _fsm: PhantomData<
                 // If the action succeeded, update its status to
                 // completed and return the created events.
                 Ok(events) => {
-                    update_action_status(
-                        &tx, id, ActionStatus::Completed, None, PhantomData::<S>
-                    )?;
+                    update_action_status(&tx, id, ActionStatus::Completed, None, PhantomData::<S>)?;
                     events
-                },
+                }
 
                 // If the action failed, persist the debug message and
                 // return nothing.
                 Err(err) => {
                     let msg = Some(format!("{:?}", err));
-                    update_action_status(
-                        &tx, id, ActionStatus::Failed, msg, PhantomData::<S>
-                    )?;
+                    update_action_status(&tx, id, ActionStatus::Failed, msg, PhantomData::<S>)?;
                     vec![]
-                },
+                }
             }
-        },
+        }
 
         _ => {
             // TODO: Currently only pending actions are run because
             // retryable actions are not yet implemented.
             vec![]
-        },
+        }
     };
 
     tx.commit().context("failed to commit transaction")?;
diff --git a/users/tazjin/finito/finito-postgres/src/tests.rs b/users/tazjin/finito/finito-postgres/src/tests.rs
index b1b5821be3..dd270c3875 100644
--- a/users/tazjin/finito/finito-postgres/src/tests.rs
+++ b/users/tazjin/finito/finito-postgres/src/tests.rs
@@ -16,7 +16,11 @@ fn test_insert_machine() {
     let door = insert_machine(&conn, initial).expect("Failed to insert door");
     let result = get_machine(&conn, &door, false).expect("Failed to fetch door");
 
-    assert_eq!(result, DoorState::Opened, "Inserted door state should match");
+    assert_eq!(
+        result,
+        DoorState::Opened,
+        "Inserted door state should match"
+    );
 }
 
 #[test]
@@ -41,7 +45,10 @@ fn test_advance() {
     }
 
     let result = get_machine(&conn, &door, false).expect("Failed to fetch door");
-    let expected = DoorState::Locked { code: 4567, attempts: 2 };
+    let expected = DoorState::Locked {
+        code: 4567,
+        attempts: 2,
+    };
 
     assert_eq!(result, expected, "Advanced door state should match");
 }
diff --git a/users/tazjin/keys.nix b/users/tazjin/keys/default.nix
index 1713ff8e91..1713ff8e91 100644
--- a/users/tazjin/keys.nix
+++ b/users/tazjin/keys/default.nix
diff --git a/users/tazjin/rlox/src/bytecode/compiler.rs b/users/tazjin/rlox/src/bytecode/compiler.rs
index 3e8a80653f..89584f19d7 100644
--- a/users/tazjin/rlox/src/bytecode/compiler.rs
+++ b/users/tazjin/rlox/src/bytecode/compiler.rs
@@ -63,9 +63,11 @@ enum Precedence {
     Equality,   // == !=
     Comparison, // < > <= >=
     Term,       // + -
-    Factor,     // * /
-    Unary,      // ! -
-    Call,       // . ()
+    Factor,     //
+    // 
+    // * /
+    Unary, // ! -
+    Call,  // . ()
     Primary,
 }
 
@@ -78,11 +80,7 @@ struct ParseRule<T: Iterator<Item = Token>> {
 }
 
 impl<T: Iterator<Item = Token>> ParseRule<T> {
-    fn new(
-        prefix: Option<ParseFn<T>>,
-        infix: Option<ParseFn<T>>,
-        precedence: Precedence,
-    ) -> Self {
+    fn new(prefix: Option<ParseFn<T>>, infix: Option<ParseFn<T>>, precedence: Precedence) -> Self {
         ParseRule {
             prefix,
             infix,
@@ -105,18 +103,16 @@ impl Precedence {
             Precedence::Factor => Precedence::Unary,
             Precedence::Unary => Precedence::Call,
             Precedence::Call => Precedence::Primary,
-            Precedence::Primary => panic!(
-                "invalid parser state: no higher precedence than Primary"
-            ),
+            Precedence::Primary => {
+                panic!("invalid parser state: no higher precedence than Primary")
+            }
         }
     }
 }
 
 fn rule_for<T: Iterator<Item = Token>>(token: &TokenKind) -> ParseRule<T> {
     match token {
-        TokenKind::LeftParen => {
-            ParseRule::new(Some(Compiler::grouping), None, Precedence::None)
-        }
+        TokenKind::LeftParen => ParseRule::new(Some(Compiler::grouping), None, Precedence::None),
 
         TokenKind::Minus => ParseRule::new(
             Some(Compiler::unary),
@@ -124,57 +120,33 @@ fn rule_for<T: Iterator<Item = Token>>(token: &TokenKind) -> ParseRule<T> {
             Precedence::Term,
         ),
 
-        TokenKind::Plus => {
-            ParseRule::new(None, Some(Compiler::binary), Precedence::Term)
-        }
+        TokenKind::Plus => ParseRule::new(None, Some(Compiler::binary), Precedence::Term),
 
-        TokenKind::Slash => {
-            ParseRule::new(None, Some(Compiler::binary), Precedence::Factor)
-        }
+        TokenKind::Slash => ParseRule::new(None, Some(Compiler::binary), Precedence::Factor),
 
-        TokenKind::Star => {
-            ParseRule::new(None, Some(Compiler::binary), Precedence::Factor)
-        }
+        TokenKind::Star => ParseRule::new(None, Some(Compiler::binary), Precedence::Factor),
 
-        TokenKind::Number(_) => {
-            ParseRule::new(Some(Compiler::number), None, Precedence::None)
-        }
+        TokenKind::Number(_) => ParseRule::new(Some(Compiler::number), None, Precedence::None),
 
-        TokenKind::True => {
-            ParseRule::new(Some(Compiler::literal), None, Precedence::None)
-        }
+        TokenKind::True => ParseRule::new(Some(Compiler::literal), None, Precedence::None),
 
-        TokenKind::False => {
-            ParseRule::new(Some(Compiler::literal), None, Precedence::None)
-        }
+        TokenKind::False => ParseRule::new(Some(Compiler::literal), None, Precedence::None),
 
-        TokenKind::Nil => {
-            ParseRule::new(Some(Compiler::literal), None, Precedence::None)
-        }
+        TokenKind::Nil => ParseRule::new(Some(Compiler::literal), None, Precedence::None),
 
-        TokenKind::Bang => {
-            ParseRule::new(Some(Compiler::unary), None, Precedence::None)
-        }
+        TokenKind::Bang => ParseRule::new(Some(Compiler::unary), None, Precedence::None),
 
-        TokenKind::BangEqual => {
-            ParseRule::new(None, Some(Compiler::binary), Precedence::Equality)
-        }
+        TokenKind::BangEqual => ParseRule::new(None, Some(Compiler::binary), Precedence::Equality),
 
-        TokenKind::EqualEqual => {
-            ParseRule::new(None, Some(Compiler::binary), Precedence::Equality)
-        }
+        TokenKind::EqualEqual => ParseRule::new(None, Some(Compiler::binary), Precedence::Equality),
 
-        TokenKind::Greater => {
-            ParseRule::new(None, Some(Compiler::binary), Precedence::Comparison)
-        }
+        TokenKind::Greater => ParseRule::new(None, Some(Compiler::binary), Precedence::Comparison),
 
         TokenKind::GreaterEqual => {
             ParseRule::new(None, Some(Compiler::binary), Precedence::Comparison)
         }
 
-        TokenKind::Less => {
-            ParseRule::new(None, Some(Compiler::binary), Precedence::Comparison)
-        }
+        TokenKind::Less => ParseRule::new(None, Some(Compiler::binary), Precedence::Comparison),
 
         TokenKind::LessEqual => {
             ParseRule::new(None, Some(Compiler::binary), Precedence::Comparison)
@@ -184,9 +156,7 @@ fn rule_for<T: Iterator<Item = Token>>(token: &TokenKind) -> ParseRule<T> {
             ParseRule::new(Some(Compiler::variable), None, Precedence::None)
         }
 
-        TokenKind::String(_) => {
-            ParseRule::new(Some(Compiler::string), None, Precedence::None)
-        }
+        TokenKind::String(_) => ParseRule::new(Some(Compiler::string), None, Precedence::None),
 
         _ => ParseRule::new(None, None, Precedence::None),
     }
@@ -236,9 +206,7 @@ impl<T: Iterator<Item = Token>> Compiler<T> {
 
     fn define_variable(&mut self, var: Option<ConstantIdx>) -> LoxResult<()> {
         if self.locals.scope_depth == 0 {
-            self.emit_op(OpCode::OpDefineGlobal(
-                var.expect("should be global"),
-            ));
+            self.emit_op(OpCode::OpDefineGlobal(var.expect("should be global")));
         } else {
             self.locals
                 .locals
@@ -305,9 +273,7 @@ impl<T: Iterator<Item = Token>> Compiler<T> {
     }
 
     fn block(&mut self) -> LoxResult<()> {
-        while !self.check(&TokenKind::RightBrace)
-            && !self.check(&TokenKind::Eof)
-        {
+        while !self.check(&TokenKind::RightBrace) && !self.check(&TokenKind::Eof) {
             self.declaration()?;
         }
 
@@ -712,9 +678,8 @@ impl<T: Iterator<Item = Token>> Compiler<T> {
 
 pub fn compile(code: &str) -> Result<(Interner, Chunk), Vec<Error>> {
     let chars = code.chars().collect::<Vec<char>>();
-    let tokens = scanner::scan(&chars).map_err(|errors| {
-        errors.into_iter().map(Into::into).collect::<Vec<Error>>()
-    })?;
+    let tokens = scanner::scan(&chars)
+        .map_err(|errors| errors.into_iter().map(Into::into).collect::<Vec<Error>>())?;
 
     let mut compiler = Compiler {
         tokens: tokens.into_iter().peekable(),
diff --git a/users/tazjin/rlox/src/bytecode/mod.rs b/users/tazjin/rlox/src/bytecode/mod.rs
index c6f3a737ae..117f17824a 100644
--- a/users/tazjin/rlox/src/bytecode/mod.rs
+++ b/users/tazjin/rlox/src/bytecode/mod.rs
@@ -23,10 +23,7 @@ impl crate::Lox for Interpreter {
         Interpreter {}
     }
 
-    fn interpret(
-        &mut self,
-        code: String,
-    ) -> Result<Self::Value, Vec<Self::Error>> {
+    fn interpret(&mut self, code: String) -> Result<Self::Value, Vec<Self::Error>> {
         let (strings, chunk) = compiler::compile(&code)?;
         vm::interpret(strings, chunk).map_err(|e| vec![e])
     }
diff --git a/users/tazjin/rlox/src/bytecode/vm.rs b/users/tazjin/rlox/src/bytecode/vm.rs
index d287ec7cb8..30ffebc79c 100644
--- a/users/tazjin/rlox/src/bytecode/vm.rs
+++ b/users/tazjin/rlox/src/bytecode/vm.rs
@@ -118,12 +118,7 @@ impl VM {
 
                 OpCode::OpNegate => {
                     let v = self.pop();
-                    with_type!(
-                        self,
-                        v,
-                        Value::Number(num),
-                        self.push(Value::Number(-num))
-                    );
+                    with_type!(self, v, Value::Number(num), self.push(Value::Number(-num)));
                 }
 
                 OpCode::OpSubtract => binary_op!(self, Number, -),
@@ -141,15 +136,18 @@ impl VM {
                             self.push(Value::String(new_s.into()));
                         }
 
-                        (Value::Number(n_a), Value::Number(n_b)) =>
-                            self.push(Value::Number(n_a + n_b)),
+                        (Value::Number(n_a), Value::Number(n_b)) => {
+                            self.push(Value::Number(n_a + n_b))
+                        }
 
-                        _ => return Err(Error {
-                            line: self.chunk.get_line(self.ip - 1),
-                            kind: ErrorKind::TypeError(
-                                "'+' operator only works on strings and numbers".into()
-                            ),
-                        })
+                        _ => {
+                            return Err(Error {
+                                line: self.chunk.get_line(self.ip - 1),
+                                kind: ErrorKind::TypeError(
+                                    "'+' operator only works on strings and numbers".into(),
+                                ),
+                            })
+                        }
                     }
                 }
 
@@ -205,8 +203,7 @@ impl VM {
                         self.stack.len() > local_idx.0,
                         "stack is not currently large enough for local"
                     );
-                    self.stack[local_idx.0] =
-                        self.stack.last().unwrap().clone();
+                    self.stack[local_idx.0] = self.stack.last().unwrap().clone();
                 }
 
                 OpCode::OpJumpPlaceholder(_) => {
@@ -255,9 +252,7 @@ impl VM {
     fn print_value(&self, val: Value) -> String {
         match val {
             Value::String(LoxString::Heap(s)) => s,
-            Value::String(LoxString::Interned(id)) => {
-                self.strings.lookup(id).into()
-            }
+            Value::String(LoxString::Interned(id)) => self.strings.lookup(id).into(),
             _ => format!("{:?}", val),
         }
     }
diff --git a/users/tazjin/rlox/src/main.rs b/users/tazjin/rlox/src/main.rs
index 2d8cf4f354..ee61ae01a1 100644
--- a/users/tazjin/rlox/src/main.rs
+++ b/users/tazjin/rlox/src/main.rs
@@ -1,8 +1,5 @@
-use std::env;
-use std::fs;
-use std::io;
 use std::io::Write;
-use std::process;
+use std::{env, fs, io, process};
 
 mod bytecode;
 mod scanner;
@@ -15,10 +12,7 @@ pub trait Lox {
     type Error: std::fmt::Display;
 
     fn create() -> Self;
-    fn interpret(
-        &mut self,
-        source: String,
-    ) -> Result<Self::Value, Vec<Self::Error>>;
+    fn interpret(&mut self, source: String) -> Result<Self::Value, Vec<Self::Error>>;
 }
 
 fn main() {
@@ -29,9 +23,7 @@ fn main() {
     }
 
     match env::var("LOX_INTERPRETER").as_ref().map(String::as_str) {
-        Ok("treewalk") => {
-            pick::<treewalk::interpreter::Interpreter>(args.nth(1))
-        }
+        Ok("treewalk") => pick::<treewalk::interpreter::Interpreter>(args.nth(1)),
         _ => pick::<bytecode::Interpreter>(args.nth(1)),
     }
 }
@@ -46,8 +38,7 @@ fn pick<I: Lox>(file_arg: Option<String>) {
 
 // Run Lox code from a file and print results to stdout
 fn run_file<I: Lox>(file: &str) {
-    let contents =
-        fs::read_to_string(file).expect("failed to read the input file");
+    let contents = fs::read_to_string(file).expect("failed to read the input file");
     let mut lox = I::create();
     run(&mut lox, contents);
 }
diff --git a/users/tazjin/rlox/src/scanner.rs b/users/tazjin/rlox/src/scanner.rs
index 4e8f07b61f..314b56d6d3 100644
--- a/users/tazjin/rlox/src/scanner.rs
+++ b/users/tazjin/rlox/src/scanner.rs
@@ -106,15 +106,9 @@ impl<'a> Scanner<'a> {
 
             // possible multi-character tokens
             '!' => self.add_if_next('=', TokenKind::BangEqual, TokenKind::Bang),
-            '=' => {
-                self.add_if_next('=', TokenKind::EqualEqual, TokenKind::Equal)
-            }
+            '=' => self.add_if_next('=', TokenKind::EqualEqual, TokenKind::Equal),
             '<' => self.add_if_next('=', TokenKind::LessEqual, TokenKind::Less),
-            '>' => self.add_if_next(
-                '=',
-                TokenKind::GreaterEqual,
-                TokenKind::Greater,
-            ),
+            '>' => self.add_if_next('=', TokenKind::GreaterEqual, TokenKind::Greater),
 
             '/' => {
                 // support comments until EOL by discarding characters
@@ -234,8 +228,7 @@ impl<'a> Scanner<'a> {
             self.advance();
         }
 
-        let ident: String =
-            self.source[self.start..self.current].iter().collect();
+        let ident: String = self.source[self.start..self.current].iter().collect();
 
         // Determine whether this is an identifier, or a keyword:
         let token_kind = match ident.as_str() {
diff --git a/users/tazjin/rlox/src/treewalk/interpreter.rs b/users/tazjin/rlox/src/treewalk/interpreter.rs
index d9fe336616..3285775bbe 100644
--- a/users/tazjin/rlox/src/treewalk/interpreter.rs
+++ b/users/tazjin/rlox/src/treewalk/interpreter.rs
@@ -34,11 +34,7 @@ impl Callable {
         }
     }
 
-    fn call(
-        &self,
-        lox: &mut Interpreter,
-        args: Vec<Value>,
-    ) -> Result<Value, Error> {
+    fn call(&self, lox: &mut Interpreter, args: Vec<Value>) -> Result<Value, Error> {
         match self {
             Callable::Builtin(builtin) => builtin.call(args),
 
@@ -50,10 +46,8 @@ impl Callable {
                     fn_env.define(param, value)?;
                 }
 
-                let result = lox.interpret_block_with_env(
-                    Some(Rc::new(RwLock::new(fn_env))),
-                    &func.body,
-                );
+                let result =
+                    lox.interpret_block_with_env(Some(Rc::new(RwLock::new(fn_env))), &func.body);
 
                 match result {
                     // extract returned values if applicable
@@ -109,22 +103,13 @@ pub struct Environment {
 }
 
 impl Environment {
-    fn define(
-        &mut self,
-        name: &scanner::Token,
-        value: Value,
-    ) -> Result<(), Error> {
+    fn define(&mut self, name: &scanner::Token, value: Value) -> Result<(), Error> {
         let ident = identifier_str(name)?;
         self.values.insert(ident.into(), value);
         Ok(())
     }
 
-    fn get(
-        &self,
-        ident: &str,
-        line: usize,
-        depth: usize,
-    ) -> Result<Value, Error> {
+    fn get(&self, ident: &str, line: usize, depth: usize) -> Result<Value, Error> {
         if depth > 0 {
             match &self.enclosing {
                 None => {
@@ -137,9 +122,7 @@ impl Environment {
                     })
                 }
                 Some(parent) => {
-                    let env = parent
-                        .read()
-                        .expect("fatal: environment lock poisoned");
+                    let env = parent.read().expect("fatal: environment lock poisoned");
                     return env.get(ident, line, depth - 1);
                 }
             }
@@ -154,11 +137,7 @@ impl Environment {
             })
     }
 
-    fn assign(
-        &mut self,
-        name: &scanner::Token,
-        value: Value,
-    ) -> Result<(), Error> {
+    fn assign(&mut self, name: &scanner::Token, value: Value) -> Result<(), Error> {
         let ident = identifier_str(name)?;
 
         match self.values.get_mut(ident) {
@@ -242,22 +221,14 @@ impl Lox for Interpreter {
 
 impl Interpreter {
     // Environment modification helpers
-    fn define_var(
-        &mut self,
-        name: &scanner::Token,
-        value: Value,
-    ) -> Result<(), Error> {
+    fn define_var(&mut self, name: &scanner::Token, value: Value) -> Result<(), Error> {
         self.env
             .write()
             .expect("environment lock is poisoned")
             .define(name, value)
     }
 
-    fn assign_var(
-        &mut self,
-        name: &scanner::Token,
-        value: Value,
-    ) -> Result<(), Error> {
+    fn assign_var(&mut self, name: &scanner::Token, value: Value) -> Result<(), Error> {
         self.env
             .write()
             .expect("environment lock is poisoned")
@@ -271,11 +242,10 @@ impl Interpreter {
             kind: ErrorKind::UndefinedVariable(ident.into()),
         })?;
 
-        self.env.read().expect("environment lock is poisoned").get(
-            ident,
-            var.name.line,
-            depth,
-        )
+        self.env
+            .read()
+            .expect("environment lock is poisoned")
+            .get(ident, var.name.line, depth)
     }
 
     /// Interpret the block in the supplied environment. If no
@@ -324,16 +294,10 @@ impl Interpreter {
                 Value::Literal(Literal::String(output))
             }
             Statement::Var(var) => return self.interpret_var(var),
-            Statement::Block(block) => {
-                return self.interpret_block_with_env(None, block)
-            }
+            Statement::Block(block) => return self.interpret_block_with_env(None, block),
             Statement::If(if_stmt) => return self.interpret_if(if_stmt),
-            Statement::While(while_stmt) => {
-                return self.interpret_while(while_stmt)
-            }
-            Statement::Function(func) => {
-                return self.interpret_function(func.clone())
-            }
+            Statement::While(while_stmt) => return self.interpret_while(while_stmt),
+            Statement::Function(func) => return self.interpret_function(func.clone()),
             Statement::Return(ret) => {
                 return Err(Error {
                     line: 0,
@@ -348,9 +312,7 @@ impl Interpreter {
     fn interpret_var(&mut self, var: &parser::Var) -> Result<Value, Error> {
         let init = var.initialiser.as_ref().ok_or_else(|| Error {
             line: var.name.line,
-            kind: ErrorKind::InternalError(
-                "missing variable initialiser".into(),
-            ),
+            kind: ErrorKind::InternalError("missing variable initialiser".into()),
         })?;
         let value = self.eval(init)?;
         self.define_var(&var.name, value.clone())?;
@@ -369,10 +331,7 @@ impl Interpreter {
         }
     }
 
-    fn interpret_while(
-        &mut self,
-        stmt: &parser::While,
-    ) -> Result<Value, Error> {
+    fn interpret_while(&mut self, stmt: &parser::While) -> Result<Value, Error> {
         let mut value = Value::Literal(Literal::Nil);
         while eval_truthy(&self.eval(&stmt.condition)?) {
             value = self.interpret_stmt(&stmt.body)?;
@@ -381,10 +340,7 @@ impl Interpreter {
         Ok(value)
     }
 
-    fn interpret_function(
-        &mut self,
-        func: Rc<parser::Function>,
-    ) -> Result<Value, Error> {
+    fn interpret_function(&mut self, func: Rc<parser::Function>) -> Result<Value, Error> {
         let name = func.name.clone();
         let value = Value::Callable(Callable::Function {
             func,
@@ -414,9 +370,7 @@ impl Interpreter {
             (TokenKind::Minus, Value::Literal(Literal::Number(num))) => {
                 Ok(Literal::Number(-num).into())
             }
-            (TokenKind::Bang, right) => {
-                Ok(Literal::Boolean(!eval_truthy(&right)).into())
-            }
+            (TokenKind::Bang, right) => Ok(Literal::Boolean(!eval_truthy(&right)).into()),
 
             (op, right) => Err(Error {
                 line: expr.operator.line,
@@ -478,10 +432,7 @@ impl Interpreter {
         Ok(value)
     }
 
-    fn eval_logical(
-        &mut self,
-        logical: &parser::Logical,
-    ) -> Result<Value, Error> {
+    fn eval_logical(&mut self, logical: &parser::Logical) -> Result<Value, Error> {
         let left = eval_truthy(&self.eval(&logical.left)?);
         let right = eval_truthy(&self.eval(&logical.right)?);
 
@@ -490,10 +441,7 @@ impl Interpreter {
             TokenKind::Or => Ok(Literal::Boolean(left || right).into()),
             kind => Err(Error {
                 line: logical.operator.line,
-                kind: ErrorKind::InternalError(format!(
-                    "Invalid logical operator: {:?}",
-                    kind
-                )),
+                kind: ErrorKind::InternalError(format!("Invalid logical operator: {:?}", kind)),
             }),
         }
     }
@@ -504,10 +452,7 @@ impl Interpreter {
             Value::Literal(v) => {
                 return Err(Error {
                     line: call.paren.line,
-                    kind: ErrorKind::RuntimeError(format!(
-                        "not callable: {:?}",
-                        v
-                    )),
+                    kind: ErrorKind::RuntimeError(format!("not callable: {:?}", v)),
                 })
             }
         };
@@ -546,10 +491,7 @@ fn eval_truthy(lit: &Value) -> bool {
     }
 }
 
-fn set_enclosing_env(
-    this: &RwLock<Environment>,
-    parent: Rc<RwLock<Environment>>,
-) {
+fn set_enclosing_env(this: &RwLock<Environment>, parent: Rc<RwLock<Environment>>) {
     this.write()
         .expect("environment lock is poisoned")
         .enclosing = Some(parent);
diff --git a/users/tazjin/rlox/src/treewalk/parser.rs b/users/tazjin/rlox/src/treewalk/parser.rs
index 003cc34b46..5794b42d15 100644
--- a/users/tazjin/rlox/src/treewalk/parser.rs
+++ b/users/tazjin/rlox/src/treewalk/parser.rs
@@ -124,56 +124,54 @@ pub enum Statement {
 
 // Parser
 
-/*
-program        → declaration* EOF ;
-
-declaration    → funDecl
-               | varDecl
-               | statement ;
-
-funDecl        → "fun" function ;
-function       → IDENTIFIER "(" parameters? ")" block ;
-parameters     → IDENTIFIER ( "," IDENTIFIER )* ;
-
-
-statement      → exprStmt
-               | forStmt
-               | ifStmt
-               | printStmt
-               | returnStmt
-               | whileStmt
-               | block ;
-
-forStmt        → "for" "(" ( varDecl | exprStmt | ";" )
-                 expression? ";"
-                 expression? ")" statement ;
-
-returnStmt     → "return" expression? ";" ;
-
-whileStmt      → "while" "(" expression ")" statement ;
-
-exprStmt       → expression ";" ;
-
-ifStmt         → "if" "(" expression ")" statement
-               ( "else" statement )? ;
-
-printStmt      → "print" expression ";" ;
-
-expression     → assignment ;
-assignment     → IDENTIFIER "=" assignment
-               | logic_or ;
-logic_or       → logic_and ( "or" logic_and )* ;
-logic_and      → equality ( "and" equality )* ;
-equality       → comparison ( ( "!=" | "==" ) comparison )* ;
-comparison     → term ( ( ">" | ">=" | "<" | "<=" ) term )* ;
-term           → factor ( ( "-" | "+" ) factor )* ;
-factor         → unary ( ( "/" | "*" ) unary )* ;
-unary          → ( "!" | "-" ) unary | call ;
-call           → primary ( "(" arguments? ")" )* ;
-arguments      → expression ( "," expression )* ;
-primary        → NUMBER | STRING | "true" | "false" | "nil"
-               | "(" expression ")" ;
-*/
+// program        → declaration* EOF ;
+//
+// declaration    → funDecl
+// | varDecl
+// | statement ;
+//
+// funDecl        → "fun" function ;
+// function       → IDENTIFIER "(" parameters? ")" block ;
+// parameters     → IDENTIFIER ( "," IDENTIFIER )* ;
+//
+//
+// statement      → exprStmt
+// | forStmt
+// | ifStmt
+// | printStmt
+// | returnStmt
+// | whileStmt
+// | block ;
+//
+// forStmt        → "for" "(" ( varDecl | exprStmt | ";" )
+// expression? ";"
+// expression? ")" statement ;
+//
+// returnStmt     → "return" expression? ";" ;
+//
+// whileStmt      → "while" "(" expression ")" statement ;
+//
+// exprStmt       → expression ";" ;
+//
+// ifStmt         → "if" "(" expression ")" statement
+// ( "else" statement )? ;
+//
+// printStmt      → "print" expression ";" ;
+//
+// expression     → assignment ;
+// assignment     → IDENTIFIER "=" assignment
+// | logic_or ;
+// logic_or       → logic_and ( "or" logic_and )* ;
+// logic_and      → equality ( "and" equality )* ;
+// equality       → comparison ( ( "!=" | "==" ) comparison )* ;
+// comparison     → term ( ( ">" | ">=" | "<" | "<=" ) term )* ;
+// term           → factor ( ( "-" | "+" ) factor )* ;
+// factor         → unary ( ( "/" | "*" ) unary )* ;
+// unary          → ( "!" | "-" ) unary | call ;
+// call           → primary ( "(" arguments? ")" )* ;
+// arguments      → expression ( "," expression )* ;
+// primary        → NUMBER | STRING | "true" | "false" | "nil"
+// | "(" expression ")" ;
 
 struct Parser {
     tokens: Vec<Token>,
@@ -213,9 +211,7 @@ impl Parser {
                 if params.len() >= 255 {
                     return Err(Error {
                         line: self.peek().line,
-                        kind: ErrorKind::InternalError(
-                            "255 parameter limit exceeded.".into(),
-                        ),
+                        kind: ErrorKind::InternalError("255 parameter limit exceeded.".into()),
                     });
                 }
 
@@ -429,10 +425,7 @@ impl Parser {
 
             return Err(Error {
                 line: equals.line,
-                kind: ErrorKind::InvalidAssignmentTarget(format!(
-                    "{:?}",
-                    equals
-                )),
+                kind: ErrorKind::InvalidAssignmentTarget(format!("{:?}", equals)),
             });
         }
 
@@ -495,9 +488,7 @@ impl Parser {
     }
 
     fn unary(&mut self) -> ExprResult {
-        if self.match_token(&TokenKind::Bang)
-            || self.match_token(&TokenKind::Minus)
-        {
+        if self.match_token(&TokenKind::Bang) || self.match_token(&TokenKind::Minus) {
             return Ok(Expr::Unary(Unary {
                 operator: self.previous().clone(),
                 right: Box::new(self.unary()?),
@@ -557,10 +548,7 @@ impl Parser {
 
             TokenKind::LeftParen => {
                 let expr = self.expression()?;
-                self.consume(
-                    &TokenKind::RightParen,
-                    ErrorKind::UnmatchedParens,
-                )?;
+                self.consume(&TokenKind::RightParen, ErrorKind::UnmatchedParens)?;
                 return Ok(Expr::Grouping(Grouping(Box::new(expr))));
             }
 
@@ -632,11 +620,7 @@ impl Parser {
         &self.tokens[self.current - 1]
     }
 
-    fn consume(
-        &mut self,
-        kind: &TokenKind,
-        err: ErrorKind,
-    ) -> Result<Token, Error> {
+    fn consume(&mut self, kind: &TokenKind, err: ErrorKind) -> Result<Token, Error> {
         if self.check_token(kind) {
             return Ok(self.advance());
         }
diff --git a/users/tazjin/rlox/src/treewalk/resolver.rs b/users/tazjin/rlox/src/treewalk/resolver.rs
index 8231ce5a9e..3d12973aa0 100644
--- a/users/tazjin/rlox/src/treewalk/resolver.rs
+++ b/users/tazjin/rlox/src/treewalk/resolver.rs
@@ -56,13 +56,14 @@ impl<'a> Resolver<'a> {
                 // The resolver does not clone references, so unless
                 // the interpreter is called before the resolver this
                 // case should never happen.
-                None => return Err(Error {
-                    line: 0,
-                    kind: ErrorKind::InternalError(
-                        "multiple function references before interpretation"
-                            .into(),
-                    ),
-                }),
+                None => {
+                    return Err(Error {
+                        line: 0,
+                        kind: ErrorKind::InternalError(
+                            "multiple function references before interpretation".into(),
+                        ),
+                    })
+                }
             },
         }
     }
@@ -79,10 +80,7 @@ impl<'a> Resolver<'a> {
         Ok(())
     }
 
-    fn resolve_function(
-        &mut self,
-        func: &'a mut parser::Function,
-    ) -> Result<(), Error> {
+    fn resolve_function(&mut self, func: &'a mut parser::Function) -> Result<(), Error> {
         self.declare(&func.name.lexeme);
         self.define(&func.name.lexeme);
 
@@ -123,17 +121,13 @@ impl<'a> Resolver<'a> {
         }
     }
 
-    fn resolve_variable(
-        &mut self,
-        var: &'a mut parser::Variable,
-    ) -> Result<(), Error> {
+    fn resolve_variable(&mut self, var: &'a mut parser::Variable) -> Result<(), Error> {
         if let Some(scope) = self.scopes.last_mut() {
             if let Some(false) = scope.get(var.name.lexeme.as_str()) {
                 return Err(Error {
                     line: var.name.line,
                     kind: ErrorKind::StaticError(
-                        "can't read local variable in its own initialiser"
-                            .into(),
+                        "can't read local variable in its own initialiser".into(),
                     ),
                 });
             }
@@ -143,10 +137,7 @@ impl<'a> Resolver<'a> {
         Ok(())
     }
 
-    fn resolve_assign(
-        &mut self,
-        assign: &'a mut parser::Assign,
-    ) -> Result<(), Error> {
+    fn resolve_assign(&mut self, assign: &'a mut parser::Assign) -> Result<(), Error> {
         self.resolve_expr(&mut assign.value)?;
         assign.depth = self.resolve_local(&assign.name);
         Ok(())
@@ -162,10 +153,7 @@ impl<'a> Resolver<'a> {
         None
     }
 
-    fn resolve_call(
-        &mut self,
-        call: &'a mut parser::Call,
-    ) -> Result<(), Error> {
+    fn resolve_call(&mut self, call: &'a mut parser::Call) -> Result<(), Error> {
         self.resolve_expr(&mut call.callee)?;
 
         for arg in call.args.iter_mut() {
@@ -198,10 +186,7 @@ impl<'a> Resolver<'a> {
     }
 }
 
-pub fn resolve(
-    globals: &[String],
-    block: &mut parser::Block,
-) -> Result<(), Error> {
+pub fn resolve(globals: &[String], block: &mut parser::Block) -> Result<(), Error> {
     let mut resolver: Resolver = Default::default();
 
     // Scope for static globals only starts, never ends.
diff --git a/users/tazjin/rustfmt.toml b/users/tazjin/rustfmt.toml
new file mode 100644
index 0000000000..0c719dcfec
--- /dev/null
+++ b/users/tazjin/rustfmt.toml
@@ -0,0 +1,22 @@
+edition = "2021"
+newline_style = "Unix"
+
+# Default code with is 100 characters, comments should follow
+# suit.
+wrap_comments = true
+
+# The default of this option creates hard-to-read nesting of
+# conditionals, turn it off.
+combine_control_expr = false
+
+# Group imports by module, but no higher. This avoids hard-to-read
+# nested use statements.
+imports_granularity = "Module"
+
+# Avoid vertical visual clutter by unnecessarily exploding
+# block-like arguments.
+overflow_delimited_expr = true
+
+# Miscellaneous
+format_code_in_doc_comments = true
+normalize_comments = true