From 70b1b2266d9d7ffead9ba764dd9a1c24cb24c191 Mon Sep 17 00:00:00 2001
From: pantonshire <tom@tomandtally.co.uk>
Date: Wed, 16 Aug 2023 09:34:13 +0100
Subject: [PATCH] pre-written fold functions for convenience

---
 src/fold.rs | 61 +++++++++++++++++++++++++++++++++++++++++++++++++++++
 src/lib.rs  | 20 ++----------------
 2 files changed, 63 insertions(+), 18 deletions(-)
 create mode 100644 src/fold.rs

diff --git a/src/fold.rs b/src/fold.rs
new file mode 100644
index 0000000..2bfc315
--- /dev/null
+++ b/src/fold.rs
@@ -0,0 +1,61 @@
+//! Pre-written fold functions which can be passed to [`Debouncer::new`](crate::Debouncer::new) to
+//! specify how raw events should be combined into a single debounced event.
+
+/// A fold function which combines events of type `T` into a `Vec<T>` by pushing them.
+/// 
+/// ```
+/// # fn main() -> Result<(), Box<dyn std::error::Error>> {
+/// # use treacle::{Debouncer, fold::fold_vec_push};
+/// use std::{time::Duration, thread};
+/// 
+/// let (debouncer, rx) = Debouncer::new(
+///     Duration::from_millis(100),
+///     fold_vec_push::<u32>
+/// )?;
+///
+/// debouncer.debounce(4);
+/// debouncer.debounce(5);
+///
+/// thread::sleep(Duration::from_millis(150));
+/// debouncer.debounce(3);
+/// debouncer.debounce(2);
+/// debouncer.debounce(1);
+///
+/// assert_eq!(rx.recv().unwrap(), vec![4, 5]);
+/// assert_eq!(rx.recv().unwrap(), vec![3, 2, 1]);
+/// # Ok(())
+/// # }
+/// ```
+pub fn fold_vec_push<T>(acc: Option<Vec<T>>, e: T) -> Vec<T> {
+    let mut acc = acc.unwrap_or_default();
+    acc.push(e);
+    acc
+}
+
+/// A fold function which discards all raw event data. Useful when you are just interested in the
+/// existence of events and not any data associated with them.
+/// 
+/// ```
+/// # fn main() -> Result<(), Box<dyn std::error::Error>> {
+/// # use treacle::{Debouncer, fold::fold_unit};
+/// use std::{time::Duration, thread};
+/// 
+/// let (debouncer, rx) = Debouncer::new(
+///     Duration::from_millis(100),
+///     fold_unit::<u32>
+/// )?;
+///
+/// debouncer.debounce(4);
+/// debouncer.debounce(5);
+///
+/// thread::sleep(Duration::from_millis(150));
+/// debouncer.debounce(3);
+/// debouncer.debounce(2);
+/// debouncer.debounce(1);
+///
+/// assert_eq!(rx.recv().unwrap(), ());
+/// assert_eq!(rx.recv().unwrap(), ());
+/// # Ok(())
+/// # }
+/// ```
+pub fn fold_unit<T>(_acc: Option<()>, _e: T) {}
diff --git a/src/lib.rs b/src/lib.rs
index c92718b..0e58337 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -1,3 +1,5 @@
+pub mod fold;
+
 use std::{
     sync::{Arc, Mutex, Condvar, mpsc},
     time::Duration,
@@ -166,24 +168,6 @@ where
     }
 }
 
-// impl<T> Debouncer<Vec<T>> {
-//     #[inline]
-//     pub fn debounce_push(&self, event_data: T) {
-//         self.debounce(event_data, |acc, event_data| {
-//             let mut acc = acc.unwrap_or_default();
-//             acc.push(event_data);
-//             acc
-//         });
-//     }
-// }
-
-// impl Debouncer<()> {
-//     #[inline]
-//     pub fn debounce_unit(&self) {
-//         self.debounce((), |_acc, _event_data| ());
-//     }
-// }
-
 impl<RawEvent, DebouncedEvent, FoldFn> Drop for Debouncer<RawEvent, DebouncedEvent, FoldFn> {
     fn drop(&mut self) {
         self.controller.notify_shutdown();