Implement addition between colors and idents

src/builtin/color.rs

@@ -1,5 +1,4 @@
 use std::collections::BTreeMap;
-use std::convert::TryInto;
 
 use num_bigint::BigInt;
 

src/value/ops.rs

@@ -24,7 +24,14 @@ impl Add for Value {
                 _ => todo!(),
             },
             // Self::List(..) => todo!(),
-            // Self::Color(..) => todo!(),
+            Self::Color(c) => match other {
+                Self::Ident(s, QuoteKind::Double) | Self::Ident(s, QuoteKind::Single) => {
+                    Value::Ident(format!("{}{}", c, s), QuoteKind::Double)
+                }
+                Self::Null => Value::Ident(c.to_string(), QuoteKind::None),
+                Self::Color(..) => todo!("figure out if it's possible to add colors"),
+                _ => Value::Ident(format!("{}{}", c, other), QuoteKind::None),
+            }
             // Self::BinaryOp(..) => todo!(),
             // Self::Paren(..) => todo!(),
             Self::Ident(s1, quotes1) => match other {
@@ -52,6 +59,13 @@ impl Add for Value {
                     };
                     Value::Ident(s1, quotes)
                 }
+                Self::Color(c) => {
+                    let quotes = match quotes1 {
+                        QuoteKind::Double | QuoteKind::Single => QuoteKind::Double,
+                        QuoteKind::None => QuoteKind::None,
+                    };
+                    Value::Ident(format!("{}{}", s1, c), quotes)
+                }
                 _ => todo!(),
             },
             _ => todo!(),

tests/color.rs

@@ -116,3 +116,23 @@ test!(
     "a {\n  color: hsla($hue: 193, $saturation: 67%, $luminance: 99, $alpha: .6);\n}\n",
     "a {\n  color: rgba(251, 253, 254, 0.6);\n}\n"
 );
+test!(
+    color_plus_ident,
+    "a {\n  color: red + foo;\n}\n",
+    "a {\n  color: redfoo;\n}\n"
+);
+test!(
+    ident_plus_color,
+    "a {\n  color: foo + red;\n}\n",
+    "a {\n  color: foored;\n}\n"
+);
+test!(
+    color_minus_ident,
+    "a {\n  color: red - foo;\n}\n",
+    "a {\n  color: red-foo;\n}\n"
+);
+test!(
+    ident_minus_color,
+    "a {\n  color: foo - red;\n}\n",
+    "a {\n  color: foo-red;\n}\n"
+);