From e9645208d99091434c3f07e47842b421cc3bcc40 Mon Sep 17 00:00:00 2001
From: Mark <mark@betalupi.com>
Date: Sun, 9 Apr 2023 08:39:22 -0700
Subject: [PATCH] Improved unit printing

---
 src/quantity/quantity.rs            | 15 ++++++++-------
 src/quantity/scalar/f64base.rs      |  1 +
 src/quantity/scalar/floatbase.rs    |  1 +
 src/quantity/scalar/mod.rs          |  8 ++++++++
 src/quantity/scalar/rationalbase.rs |  1 +
 src/tokens/operator.rs              | 29 +++++++++++++++++++++++++++--
 6 files changed, 46 insertions(+), 9 deletions(-)

diff --git a/src/quantity/quantity.rs b/src/quantity/quantity.rs
index 90e3d7e..a4e0f14 100644
--- a/src/quantity/quantity.rs
+++ b/src/quantity/quantity.rs
@@ -25,12 +25,13 @@ pub struct Quantity {
 
 impl ToString for Quantity {
 	fn to_string(&self) -> String {
-		let mut n = self.v.to_string();
+		let n = self.v.to_string();
 		if self.unitless() { return n; }
 
-		n.push(' ');
-		n.push_str(&self.u.to_string());
-		return n;
+		let u = self.u.to_string();
+		if self.is_one() { return u; };
+
+		return format!("{n} {u}");
 	}
 }
 
@@ -75,9 +76,8 @@ impl Quantity {
 		});
 	}
 
-	pub fn add_unit(&mut self, ui: BaseUnit, pi: f64) {
-		self.u.insert(ui, pi)
-	}
+	pub fn insert_unit(&mut self, ui: BaseUnit, pi: f64) { self.u.insert(ui, pi) }
+	pub fn set_unit(&mut self, u: Unit) { self.u = u; }
 }
 
 
@@ -96,6 +96,7 @@ macro_rules! quant_foward {
 impl Quantity {
 
 	pub fn is_zero(&self) -> bool { self.v.is_zero() }
+	pub fn is_one(&self) -> bool { self.v.is_one() }
 	pub fn is_nan(&self) -> bool { self.v.is_nan() }
 	pub fn is_negative(&self) -> bool { self.v.is_negative() }
 	pub fn is_positive(&self) -> bool { self.v.is_positive() }
diff --git a/src/quantity/scalar/f64base.rs b/src/quantity/scalar/f64base.rs
index f672214..d272bdf 100644
--- a/src/quantity/scalar/f64base.rs
+++ b/src/quantity/scalar/f64base.rs
@@ -48,6 +48,7 @@ impl ScalarBase for F64Base {
 	foward!(fract);
 
 	fn is_zero(&self) -> bool {self.val == 0f64}
+	fn is_one(&self) -> bool {self.val == 1f64}
 	fn is_negative(&self) -> bool { self.val.is_sign_negative() }
 	fn is_positive(&self) -> bool { self.val.is_sign_positive() }
 
diff --git a/src/quantity/scalar/floatbase.rs b/src/quantity/scalar/floatbase.rs
index cb31f84..c588dc5 100644
--- a/src/quantity/scalar/floatbase.rs
+++ b/src/quantity/scalar/floatbase.rs
@@ -123,6 +123,7 @@ impl ScalarBase for FloatBase {
 	foward!(fract);
 
 	fn is_zero(&self) -> bool {self.val.is_zero()}
+	fn is_one(&self) -> bool {self.val == Float::with_val(FLOAT_PRECISION, 1)}
 	fn is_negative(&self) -> bool { self.val.is_sign_negative() }
 	fn is_positive(&self) -> bool { self.val.is_sign_positive() }
 
diff --git a/src/quantity/scalar/mod.rs b/src/quantity/scalar/mod.rs
index 4092860..22b7e9a 100644
--- a/src/quantity/scalar/mod.rs
+++ b/src/quantity/scalar/mod.rs
@@ -24,6 +24,7 @@ pub trait ScalarBase:
 	// Utility
 	fn fract(&self) -> Option<Self>;
 	fn is_zero(&self) -> bool;
+	fn is_one(&self) -> bool;
 	fn is_negative(&self) -> bool;
 	fn is_positive(&self) -> bool;
 
@@ -163,6 +164,13 @@ impl Scalar {
 		}
 	}
 
+	pub fn is_one(&self) -> bool {
+		match self {
+			Scalar::Rational{v} => v.is_one(),
+			Scalar::Float{v} => v.is_one(),
+		}
+	}
+
 	pub fn is_negative(&self) -> bool {
 		match self {
 			Scalar::Rational{v} => v.is_negative(),
diff --git a/src/quantity/scalar/rationalbase.rs b/src/quantity/scalar/rationalbase.rs
index df9d102..7c41107 100644
--- a/src/quantity/scalar/rationalbase.rs
+++ b/src/quantity/scalar/rationalbase.rs
@@ -110,6 +110,7 @@ impl ScalarBase for RationalBase {
 	}
 
 	fn is_zero(&self) -> bool {self.val == Rational::from((0,1))}
+	fn is_one(&self) -> bool {self.val == Rational::from((1,1))}
 	fn is_negative(&self) -> bool { self.val.clone().signum() == -1 }
 	fn is_positive(&self) -> bool { self.val.clone().signum() == 1 }
 
diff --git a/src/tokens/operator.rs b/src/tokens/operator.rs
index 1af5879..fca87e7 100644
--- a/src/tokens/operator.rs
+++ b/src/tokens/operator.rs
@@ -161,9 +161,34 @@ impl Operator {
 				let (b, div) = (b, div);
 
 				if div {
-					return format!("{} ÷ {}", self.add_parens_to_arg_strict(a), self.add_parens_to_arg_strict(b));
+					return format!("{} ÷ {}",
+						self.add_parens_to_arg_strict(a),
+						self.add_parens_to_arg_strict(b)
+					);
 				} else {
-					return format!("{} × {}", self.add_parens_to_arg_strict(a), self.add_parens_to_arg_strict(b));
+
+					// Ommit times sign when we have a number
+					// multiplied by a unit (like 10 m)
+					// Times sign should stay in all other cases.
+					let no_times = if let Token::Number(p) = b {
+						if let Token::Number(q) = a {
+							(!p.unitless() && p.is_one()) &&
+							!(!q.unitless() && p.is_one())
+						} else {false}
+					} else {false};
+
+					if no_times {
+						return format!("{} {}",
+							self.add_parens_to_arg_strict(a),
+							self.add_parens_to_arg_strict(b)
+						);
+					} else {
+						return format!("{} × {}",
+							self.add_parens_to_arg_strict(a),
+							self.add_parens_to_arg_strict(b)
+						);
+					}
+
 				}
 			},