chore: Add missing pub fn docs for Fp

src/fp.rs

@@ -170,6 +170,7 @@ impl Fp {
         R
     }
 
+    /// Checks if a value is equal to zero in constant time.
     pub fn is_zero(&self) -> Choice {
         self.ct_eq(&Fp::zero())
     }
@@ -321,12 +322,14 @@ impl Fp {
     }
 
     #[inline]
+    /// Performs the square root of an element in constant time.
+    ///
+    /// NOTE:
+    /// We use Shank's method, as p = 3 (mod 4). This means
+    /// we only need to exponentiate by (p+1)/4. This only
+    /// works for elements that are actually quadratic residue,
+    /// so we check that we got the correct result at the end.
     pub fn sqrt(&self) -> CtOption<Self> {
-        // We use Shank's method, as p = 3 (mod 4). This means
-        // we only need to exponentiate by (p+1)/4. This only
-        // works for elements that are actually quadratic residue,
-        // so we check that we got the correct result at the end.
-
         let sqrt = self.pow_vartime(&[
             0xee7f_bfff_ffff_eaab,
             0x07aa_ffff_ac54_ffff,
@@ -379,6 +382,7 @@ impl Fp {
     }
 
     #[inline]
+    /// Performs constant time addition of two elements.
     pub const fn add(&self, rhs: &Fp) -> Fp {
         let (d0, carry) = adc(self.0[0], rhs.0[0], 0);
         let (d1, carry) = adc(self.0[1], rhs.0[1], carry);
@@ -393,6 +397,7 @@ impl Fp {
     }
 
     #[inline]
+    /// Performs constant time negation of an element.
     pub const fn neg(&self) -> Fp {
         let (d0, borrow) = sbb(MODULUS[0], self.0[0], 0);
         let (d1, borrow) = sbb(MODULUS[1], self.0[1], borrow);
@@ -418,6 +423,7 @@ impl Fp {
     }
 
     #[inline]
+    /// Performs constant time subtraction of two elements.
     pub const fn sub(&self, rhs: &Fp) -> Fp {
         (&rhs.neg()).add(self)
     }
@@ -562,6 +568,7 @@ impl Fp {
     }
 
     #[inline]
+    /// Performs constant time multiplication of two elements.
     pub const fn mul(&self, rhs: &Fp) -> Fp {
         let (t0, carry) = mac(0, self.0[0], rhs.0[0], 0);
         let (t1, carry) = mac(0, self.0[0], rhs.0[1], carry);