From 6b0eb7608d06fbfce663e4775196cfd3c7bae643 Mon Sep 17 00:00:00 2001
From: Jason Volk <jason@zemos.net>
Date: Thu, 31 Oct 2024 07:33:16 +0000
Subject: [PATCH] add Filter extension to Result
Signed-off-by: Jason Volk <jason@zemos.net>
---
src/core/utils/result.rs | 5 +++--
src/core/utils/result/filter.rs | 21 +++++++++++++++++++++
2 files changed, 24 insertions(+), 2 deletions(-)
create mode 100644 src/core/utils/result/filter.rs
diff --git a/src/core/utils/result.rs b/src/core/utils/result.rs
index 9a60d19e..fb1b7b95 100644
--- a/src/core/utils/result.rs
+++ b/src/core/utils/result.rs
@@ -1,4 +1,5 @@
mod debug_inspect;
+mod filter;
mod flat_ok;
mod into_is_ok;
mod log_debug_err;
@@ -8,8 +9,8 @@ mod not_found;
mod unwrap_infallible;
pub use self::{
- debug_inspect::DebugInspect, flat_ok::FlatOk, into_is_ok::IntoIsOk, log_debug_err::LogDebugErr, log_err::LogErr,
- map_expect::MapExpect, not_found::NotFound, unwrap_infallible::UnwrapInfallible,
+ debug_inspect::DebugInspect, filter::Filter, flat_ok::FlatOk, into_is_ok::IntoIsOk, log_debug_err::LogDebugErr,
+ log_err::LogErr, map_expect::MapExpect, not_found::NotFound, unwrap_infallible::UnwrapInfallible,
};
pub type Result<T = (), E = crate::Error> = std::result::Result<T, E>;
diff --git a/src/core/utils/result/filter.rs b/src/core/utils/result/filter.rs
new file mode 100644
index 00000000..f11d3632
--- /dev/null
+++ b/src/core/utils/result/filter.rs
@@ -0,0 +1,21 @@
+use super::Result;
+
+pub trait Filter<T, E> {
+ /// Similar to Option::filter
+ #[must_use]
+ fn filter<P, U>(self, predicate: P) -> Self
+ where
+ P: FnOnce(&T) -> Result<(), U>,
+ E: From<U>;
+}
+
+impl<T, E> Filter<T, E> for Result<T, E> {
+ #[inline]
+ fn filter<P, U>(self, predicate: P) -> Self
+ where
+ P: FnOnce(&T) -> Result<(), U>,
+ E: From<U>,
+ {
+ self.and_then(move |t| predicate(&t).map(move |()| t).map_err(Into::into))
+ }
+}