From 2c55167dd026da4fbeb5f3216ee5eecb232b6280 Mon Sep 17 00:00:00 2001
From: Celestino Amoroso <celestino.amoroso@gmail.com>
Date: Thu, 2 May 2024 11:04:20 +0200
Subject: [PATCH] operator-fraction.go: the constructor newFraction() does call
 simplifyIntegers() on the num e den

---
 operator-fraction.go | 36 ++++++++++++++++++++++--------------
 1 file changed, 22 insertions(+), 14 deletions(-)

diff --git a/operator-fraction.go b/operator-fraction.go
index 6119179..86d9357 100644
--- a/operator-fraction.go
+++ b/operator-fraction.go
@@ -16,10 +16,11 @@ type fraction struct {
 }
 
 func newFraction(num, den int64) *fraction {
-	if den < 0 {
+	/*	if den < 0 {
 		den = -den
 		num = -num
-	}
+	}*/
+	num, den = simplifyIntegers(num, den)
 	return &fraction{num, den}
 }
 
@@ -145,12 +146,12 @@ func lcm(a, b int64) (l int64) {
 
 func sumFract(f1, f2 *fraction) (sum *fraction) {
 	m := lcm(f1.den, f2.den)
-	sum = &fraction{f1.num*(m/f1.den) + f2.num*(m/f2.den), m}
+	sum = newFraction(f1.num*(m/f1.den) + f2.num*(m/f2.den), m)
 	return
 }
 
 func mulFract(f1, f2 *fraction) (prod *fraction) {
-	prod = &fraction{f1.num * f2.num, f1.den * f2.den}
+	prod = newFraction(f1.num * f2.num, f1.den * f2.den)
 	return
 }
 
@@ -239,23 +240,30 @@ func divAnyFract(af1, af2 any) (quot any, err error) {
 	return
 }
 
-func simplifyFraction(f *fraction) any {
-	return simplifyIntegers(f.num, f.den)
+func simplifyFraction(f *fraction) (v any) {
+	f.num, f.den = simplifyIntegers(f.num, f.den)
+	if f.den == 1 {
+		v = f.num
+	} else {
+		v = &fraction{f.num, f.den}
+	}
+	return v
 }
 
-func simplifyIntegers(num, den int64) (v any) {
+func simplifyIntegers(num, den int64) (a, b int64) {
+	if num == 0 {
+		return 0, 1
+	}
+	if den == 0 {
+		panic("fraction with denominator == 0")
+	}
 	if den < 0 {
 		den = -den
 		num = -num
 	}
 	g := gcd(num, den)
-	num = num / g
-	den = den / g
-	if den == 1 {
-		v = num
-	} else {
-		v = &fraction{num, den}
-	}
+	a = num / g
+	b = den / g
 	return
 }