fix: apply proper types to function arguments (#17)

Author: TomAFrench

src/lib.nr

@@ -61,7 +61,7 @@ where
  **/
 pub fn sort_extended<T, let N: u32>(
     input: [T; N],
-    sortfn: fn(T, T) -> bool,
+    sortfn: unconstrained fn(T, T) -> bool,
     sortfn_assert: fn(T, T) -> (),
 ) -> [T; N]
 where
@@ -82,7 +82,7 @@ pub struct SortResult<T, let N: u32> {
 }
 pub fn sort_advanced<T, let N: u32>(
     input: [T; N],
-    sortfn: fn(T, T) -> bool,
+    sortfn: unconstrained fn(T, T) -> bool,
     sortfn_assert: fn(T, T) -> (),
 ) -> SortResult<T, N>
 where
@@ -107,6 +107,10 @@ mod test {
         a <= b
     }
 
+    unconstrained fn __sort_u32(a: u32, b: u32) -> bool {
+        a <= b
+    }
+
     // unconditional_lt will cost fewer constraints than the `<=` operator
     // as we do not need to constrain the case where `a > b`, and assign a boolean variable to the result
     fn unconditional_lt(_a: u32, _b: u32) {
@@ -141,7 +145,7 @@ mod test {
     fn test_sort_extended() {
         let mut arr: [u32; 7] = [3, 6, 8, 10, 1, 2, 1];
 
-        let sorted = sort_extended(arr, sort_u32, unconditional_lt);
+        let sorted = sort_extended(arr, __sort_u32, unconditional_lt);
 
         let expected: [u32; 7] = [1, 1, 2, 3, 6, 8, 10];
         assert(sorted == expected);

src/quicksort/quicksort_explicit.nr

@@ -14,7 +14,7 @@ unconstrained fn partition<T, let N: u32>(
     arr: &mut [T; N],
     low: u32,
     high: u32,
-    sortfn: fn(T, T) -> bool,
+    sortfn: unconstrained fn(T, T) -> bool,
 ) -> u32 {
     let pivot = high;
     let mut i = low;
@@ -32,7 +32,7 @@ unconstrained fn quicksort_recursive<T, let N: u32>(
     arr: &mut [T; N],
     low: u32,
     high: u32,
-    sortfn: fn(T, T) -> bool,
+    sortfn: unconstrained fn(T, T) -> bool,
 ) {
     if low < high {
         let pivot_index = partition(arr, low, high, sortfn);
@@ -43,7 +43,10 @@ unconstrained fn quicksort_recursive<T, let N: u32>(
     }
 }
 
-pub unconstrained fn quicksort<T, let N: u32>(_arr: [T; N], sortfn: fn(T, T) -> bool) -> [T; N] {
+pub unconstrained fn quicksort<T, let N: u32>(
+    _arr: [T; N],
+    sortfn: unconstrained fn(T, T) -> bool,
+) -> [T; N] {
     let mut arr: [T; N] = _arr;
     if arr.len() <= 1 {} else {
         quicksort_recursive(&mut arr, 0, arr.len() - 1, sortfn);