Avoid unnecessary scientific notation

CHANGELOG.md

@@ -3,6 +3,8 @@
 ## Next
 - Remove the `degrees` keyword which referred to `celcius` by default
 - Remove the `default_degrees` argument from `eval()` and `lex()`. Not necessary now that the `degrees` keyword is removed
+- Fix trigonometry imprecision
+- Fix unnecessary scientific notation
 
 ## 1.9.3 - 2023 sep 20
 - Fix negative unary `-` always having higher precedence than `^`. This resulted in `-3^2` returning `9` instead of `-9`

src/lib.rs

@@ -65,11 +65,18 @@ impl Number {
 	pub const fn new(value: d128, unit: Unit) -> Number {
 		Number { value, unit }
 	}
+	pub fn get_simplified_value(&self) -> d128 {
+		// The order here matters, reduce must be first
+		// sin(pi) results in 0E-32, but .reduce() changes is to 0
+		let mut value = self.value.reduce();
+		// 0.2/0.01 results in 2E+1, but adding 0 changes it to 20
+		value = value + d128!(0);
+		value
+	}
 }
 impl Display for Number {
 	fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
-		// 0.2/0.01 results in 2E+1, but if we add zero it becomes 20
+		let value = self.get_simplified_value();
-		let value = self.value + d128!(0);
 		let word = match self.value == d128!(1) {
 			true => self.unit.singular(),
 			false => self.unit.plural(),
@@ -290,6 +297,12 @@ mod tests {
 		eval(input, true, false).unwrap()
 	}
 
+	#[test]
+	fn test_simplify() {
+		assert_eq!(&default_eval("sin(pi)").to_string(), "0");
+		assert_eq!(&default_eval("0.2/0.01").to_string(), "20");
+	}
+
 	#[test]
 	fn test_evaluations() {
 		assert_eq!(default_eval("-2(-3)"), Number::new(d128!(6), Unit::NoUnit));