Support arbitrary amount of numbers multiplied together

src/units.rs

@@ -92,8 +92,8 @@ pub(crate) enum Unit {
     /// Unspecified unit
     None,
 
-    /// Two units multiplied together
+    /// Units multiplied together
-    Mul(Box<Unit>, Box<Unit>),
+    Mul(Vec<Unit>),
     /// A unit divided by another
     Div(Box<Unit>, Box<Unit>),
 }
@@ -228,7 +228,15 @@ impl Into<String> for Unit {
             Unit::X => "x",
             Unit::Fr => "fr",
             Unit::None => "",
-            Unit::Mul(l, r) => return format!("{}*{}", l, r),
+            Unit::Mul(u) => {
+                return format!(
+                    "{}",
+                    u.into_iter()
+                        .map(|x| x.to_string())
+                        .collect::<Vec<String>>()
+                        .join("*")
+                )
+            }
             Unit::Div(l, r) => return format!("{}/{}", l, r),
             Unit::Unknown(ref s) => s,
         }
@@ -276,7 +284,14 @@ impl fmt::Display for Unit {
             Unit::Fr => write!(f, "fr"),
             Unit::Unknown(s) => write!(f, "{}", s),
             Unit::None => write!(f, ""),
-            Unit::Mul(l, r) => write!(f, "{}*{}", l, r),
+            Unit::Mul(u) => write!(
+                f,
+                "{}",
+                u.into_iter()
+                    .map(|x| x.to_string())
+                    .collect::<Vec<String>>()
+                    .join("*")
+            ),
             Unit::Div(l, r) => write!(f, "{}/{}", l, r),
         }
     }

src/value/ops.rs

@@ -204,10 +204,20 @@ impl Mul for Value {
                         Value::Dimension(num * num2, unit2)
                     } else if unit2 == Unit::None {
                         Value::Dimension(num * num2, unit)
+                    } else if let Unit::Mul(mut u) = unit {
+                        u.push(unit2);
+                        Value::Dimension(num * num2, Unit::Mul(u))
+                    } else if let Unit::Mul(u2) = unit2 {
+                        let mut u = vec![unit];
+                        u.extend(u2);
+                        Value::Dimension(num * num2, Unit::Mul(u))
                     } else {
-                        Value::Dimension(num * num2, Unit::Mul(Box::new(unit), Box::new(unit2)))
+                        Value::Dimension(num * num2, Unit::Mul(vec![unit, unit2]))
                     }
                 }
+                Self::BinaryOp(..) | Self::Paren(..) => {
+                    return Self::Dimension(num, unit) * other.eval()?
+                }
                 _ => {
                     return Err(
                         format!("Undefined operation \"{}{} * {}\".", num, unit, other).into(),
@@ -219,6 +229,7 @@ impl Mul for Value {
         })
     }
 }
+
 impl Div for Value {
     type Output = SassResult<Self>;
 

tests/units.rs

@@ -34,3 +34,13 @@ test!(
     "a {\n  color: unit(1px*1px);\n}\n",
     "a {\n  color: \"px*px\";\n}\n"
 );
+test!(
+    unit_fn_unit_times_unit_times_unit,
+    "a {\n  color: unit(1px * 1rad * 1em);\n}\n",
+    "a {\n  color: \"px*rad*em\";\n}\n"
+);
+test!(
+    unit_none_times_none_times_none,
+    "a {\n  color: 1 * 1 * 1;\n}\n",
+    "a {\n  color: 1;\n}\n"
+);