From 8b101d67c4408c1191dd0bb1ace2b9bc50b37553 Mon Sep 17 00:00:00 2001
From: David Nevado <david@davidnevado.xyz>
Date: Sat, 12 Mar 2022 15:46:43 +0100
Subject: [PATCH] Add `Coordinates` constructor

---
 src/arithmetic/curves.rs | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/src/arithmetic/curves.rs b/src/arithmetic/curves.rs
index ca94e58..44eced6 100644
--- a/src/arithmetic/curves.rs
+++ b/src/arithmetic/curves.rs
@@ -140,6 +140,11 @@ pub struct Coordinates<C: CurveAffine> {
 
 #[cfg(feature = "alloc")]
 impl<C: CurveAffine> Coordinates<C> {
+    /// Obtains a `Coordinates` value given $(x, y)$, failing if it is not on the curve.
+    pub fn from_xy(x: C::Base, y: C::Base) -> CtOption<Self> {
+        // We use CurveAffine::from_xy to validate the coordinates.
+        C::from_xy(x, y).map(|_| Coordinates { x, y })
+    }
     /// Returns the x-coordinate.
     ///
     /// Equivalent to `Coordinates::u`.