rust: Fix clippy warnings

crates/eko/src/lib.rs

@@ -1,12 +1,14 @@
 //! Interface to the eko Python package.
 
-use ekore;
 use ekore::harmonics::cache::Cache;
 use std::ffi::c_void;
 
 mod mellin;
 
 /// QCD intergration kernel inside quad.
+///
+/// # Safety
+/// This is the connection from Python, so we don't know what is on the other side.
 #[no_mangle]
 pub unsafe extern "C" fn rust_quad_ker_qcd(u: f64, rargs: *mut c_void) -> f64 {
     let args = *(rargs as *mut QuadQCDargs);
@@ -23,11 +25,11 @@ pub unsafe extern "C" fn rust_quad_ker_qcd(u: f64, rargs: *mut c_void) -> f64 {
             &mut c,
             args.nf,
         );
-        for k in 0..args.order_qcd {
-            for l in 0..2 {
-                for m in 0..2 {
-                    re.push(res[k][l][m].re);
-                    im.push(res[k][l][m].im);
+        for gamma_s in res.iter().take(args.order_qcd) {
+            for col in gamma_s.iter().take(2) {
+                for el in col.iter().take(2) {
+                    re.push(el.re);
+                    im.push(el.im);
                 }
             }
         }
@@ -38,9 +40,9 @@ pub unsafe extern "C" fn rust_quad_ker_qcd(u: f64, rargs: *mut c_void) -> f64 {
             &mut c,
             args.nf,
         );
-        for j in 0..args.order_qcd {
-            re.push(res[j].re);
-            im.push(res[j].im);
+        for el in res.iter().take(args.order_qcd) {
+            re.push(el.re);
+            im.push(el.im);
         }
     }
     // pass on
@@ -127,7 +129,10 @@ pub struct QuadQCDargs {
     pub is_threshold: bool,
 }
 
-/// empty placeholder function for python callback
+/// Empty placeholder function for python callback.
+///
+/// # Safety
+/// This is the connection back to Python, so we don't know what is on the other side.
 pub unsafe extern "C" fn my_py(
     _re_gamma: *const f64,
     _im_gamma: *const f64,
@@ -161,6 +166,9 @@ pub unsafe extern "C" fn my_py(
 ///
 /// This is required to make the arguments part of the API, otherwise it won't be added to the compiled
 /// package (since it does not appear in the signature of `quad_ker_qcd`).
+///
+/// # Safety
+/// This is the connection from and back to Python, so we don't know what is on the other side.
 #[no_mangle]
 pub unsafe extern "C" fn empty_qcd_args() -> QuadQCDargs {
     QuadQCDargs {

crates/ekore/src/harmonics/cache.rs

@@ -33,8 +33,8 @@ impl Cache {
     pub fn get(&mut self, k: K) -> Complex<f64> {
         let val = self.m.get(&k);
         // already there?
-        if val.is_some() {
-            return *val.unwrap();
+        if let Some(value) = val {
+            return *value;
         }
         // compute new
         let val = match k {

crates/ekore/src/harmonics/polygamma.rs

@@ -3,6 +3,7 @@
 use num::{complex::Complex, Zero};
 use std::f64::consts::PI;
 
+#[allow(clippy::excessive_precision, clippy::assign_op_pattern)]
 /// Compute the polygamma functions $\psi_k(z)$.
 ///
 /// Reimplementation of ``WPSIPG`` (C317) in [CERNlib](http://cernlib.web.cern.ch/cernlib/) given by [[KOLBIG1972221]][crate::bib::KOLBIG1972221].

crates/ekore/src/harmonics/w1.rs

@@ -7,5 +7,5 @@ use crate::harmonics::polygamma::cern_polygamma;
 /// $$S_1(N) = \sum\limits_{j=1}^N \frac 1 j = \psi_0(N+1)+\gamma_E$$
 /// with $\psi_0(N)$ the digamma function and $\gamma_E$ the Euler-Mascheroni constant.
 pub fn S1(N: Complex<f64>) -> Complex<f64> {
-    cern_polygamma(N + 1.0, 0) + 0.5772156649015328606065120
+    cern_polygamma(N + 1.0, 0) + 0.577_215_664_901_532_9
 }