From 074f2bf662cef5a8c71131c3d4395b913af733eb Mon Sep 17 00:00:00 2001
From: Timothy Warren <twarren@nabancard.com>
Date: Mon, 24 Feb 2020 13:49:09 -0500
Subject: [PATCH] Update docs, more tests

---
 benches/stock_functions.rs | 10 +++--
 src/lib.rs                 | 77 ++++++++++++++++++++++----------------
 src/num.rs                 |  2 +
 tests/fractions.rs         |  6 +++
 4 files changed, 58 insertions(+), 37 deletions(-)

diff --git a/benches/stock_functions.rs b/benches/stock_functions.rs
index f920b18..5314200 100644
--- a/benches/stock_functions.rs
+++ b/benches/stock_functions.rs
@@ -53,11 +53,13 @@ fn bench_gcd(c: &mut Criterion) {
 
     for input in [(small_1, small), (med_1, med), (max_1, max)].iter() {
         let param = format!("{},{}", input.0, input.1);
-        group.bench_with_input(BenchmarkId::new("Binary", &param), input, |b, input| {
-            b.iter(|| u128::gcd(black_box(input.0), black_box(input.1)))
+        group.bench_with_input(BenchmarkId::new("Binary", &param), input, |bench, input| {
+            let (a, b) = input;
+            bench.iter(|| u128::gcd(black_box(*a), black_box(*b)))
         });
-        group.bench_with_input(BenchmarkId::new("Euclid", &param), input, |b, input| {
-            b.iter(|| u128::e_gcd(black_box(input.0), black_box(input.1)))
+        group.bench_with_input(BenchmarkId::new("Euclid", &param), input, |bench, input| {
+            let (a, b) = input;
+            bench.iter(|| u128::e_gcd(black_box(*a), black_box(*b)))
         });
     }
     group.finish();
diff --git a/src/lib.rs b/src/lib.rs
index d36cee8..36a4d84 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -9,19 +9,19 @@ pub mod num;
 pub mod rational;
 
 /// Calculate a number in the fibonacci sequence,
-/// using a lookup table for better worst-case performance.
+/// using recursion and a lookup table
 ///
 /// Can calculate up to 186 using native unsigned 128 bit integers.
 ///
 /// Example:
 /// ```rust
-/// use rusty_numbers::fibonacci;
+/// use rusty_numbers::mem_fibonacci;
 ///
-/// let valid = fibonacci(45); // Some(1134903170)
-/// # assert_eq!(1134903170, fibonacci(45).unwrap());
+/// let valid = mem_fibonacci(45); // Some(1134903170)
+/// # assert_eq!(1134903170, mem_fibonacci(45).unwrap());
 /// # assert!(valid.is_some());
 ///
-/// let invalid = fibonacci(187); // None
+/// let invalid = mem_fibonacci(187); // None
 /// # assert!(invalid.is_none());
 /// ```
 #[inline]
@@ -31,34 +31,34 @@ pub fn mem_fibonacci(n: usize) -> Option<u128> {
     table[1] = 1;
     table[2] = 1;
 
-    _mem_fibonacci(n, &mut table)
-}
-
-/// Actual calculating function for `fibonacci`
-#[inline]
-fn _mem_fibonacci(n: usize, table: &mut [u128]) -> Option<u128> {
-    if n < 2 {
-        // The first values are predefined.
-        return Some(table[n]);
-    }
-
-    if n > 186 {
-        return None;
-    }
-
-    match table[n] {
-        // The lookup array starts out zeroed, so a zero
-        // is a not yet calculated value
-        0 => {
-            let a = _mem_fibonacci(n - 1, table)?;
-            let b = _mem_fibonacci(n - 2, table)?;
-
-            table[n] = a + b;
-
-            Some(table[n])
+    /// Actual calculating function for `fibonacci`
+    #[inline]
+    fn f(n: usize, table: &mut [u128]) -> Option<u128> {
+        if n < 2 {
+            // The first values are predefined.
+            return Some(table[n]);
+        }
+
+        if n > 186 {
+            return None;
+        }
+
+        match table[n] {
+            // The lookup array starts out zeroed, so a zero
+            // is a not yet calculated value
+            0 => {
+                let a = f(n - 1, table)?;
+                let b = f(n - 2, table)?;
+
+                table[n] = a + b;
+
+                Some(table[n])
+            }
+            x => Some(x),
         }
-        x => Some(x),
     }
+
+    f(n, &mut table)
 }
 
 /// Calculate a number in the fibonacci sequence,
@@ -82,9 +82,20 @@ pub fn rec_fibonacci(n: usize) -> Option<u128> {
 }
 
 /// Calculate a number in the fibonacci sequence,
-/// using iteration
 ///
-/// Can calculate up to 186
+/// Can calculate up to 186 using native unsigned 128 bit integers.
+///
+/// Example:
+/// ```rust
+/// use rusty_numbers::fibonacci;
+///
+/// let valid = fibonacci(45); // Some(1134903170)
+/// # assert_eq!(1134903170, fibonacci(45).unwrap());
+/// # assert!(valid.is_some());
+///
+/// let invalid = fibonacci(187); // None
+/// # assert!(invalid.is_none());
+/// ```
 #[inline]
 pub fn fibonacci(n: usize) -> Option<u128> {
     let mut a: u128 = 0;
diff --git a/src/num.rs b/src/num.rs
index 1b554b8..8039452 100644
--- a/src/num.rs
+++ b/src/num.rs
@@ -91,6 +91,8 @@ pub trait Int:
 
     /// Returns a tuple of the subtraction along with a boolean indicating whether an arithmetic
     /// overflow would occur. If an overflow would have occurred then the wrapped value is returned.
+    ///
+    /// The wrapped value is the amount less than the minimum value as a positive number
     fn left_overflowing_sub(self, rhs: Self) -> (Self, bool);
 
     /// Convert to an unsigned number
diff --git a/tests/fractions.rs b/tests/fractions.rs
index f7eef4f..4a93a67 100644
--- a/tests/fractions.rs
+++ b/tests/fractions.rs
@@ -1,6 +1,7 @@
 #![cfg_attr(tarpaulin, skip)]
 
 use rusty_numbers::frac;
+use rusty_numbers::rational::Frac;
 
 #[test]
 fn mul_test() {
@@ -64,6 +65,11 @@ fn zero_denom() {
     frac!(1 / 0);
 }
 
+#[test]
+fn fraction_reducing() {
+    assert_eq!(frac!(1u8/2), Frac::new_unreduced(48u8, 96u8).reduce());
+}
+
 #[test]
 fn op_assign() {
     // Addition