refactor how & is handled in values

src/selector/mod.rs

@@ -2,12 +2,14 @@ use std::fmt::{self, Display, Write};
 
 use peekmore::{PeekMore, PeekMoreIterator};
 
+use crate::common::{Brackets, ListSeparator, QuoteKind};
 use crate::error::SassResult;
 use crate::scope::Scope;
 use crate::utils::{
     devour_whitespace, eat_comment, eat_ident_no_interpolation, parse_interpolation,
     read_until_closing_paren, read_until_newline, IsWhitespace,
 };
+use crate::value::Value;
 use crate::Token;
 
 use attribute::Attribute;
@@ -25,6 +27,44 @@ struct SelectorPart {
     pub contains_super_selector: bool,
 }
 
+impl SelectorPart {
+    pub fn into_value(&self) -> Value {
+        let mut kinds = Vec::new();
+        let mut this_kind = Vec::new();
+        for kind in &self.inner {
+            match kind {
+                SelectorKind::Whitespace => {
+                    if !this_kind.is_empty() {
+                        kinds.push(SelectorPart {
+                            inner: std::mem::take(&mut this_kind),
+                            is_invisible: false,
+                            has_newline: false,
+                            contains_super_selector: false,
+                        });
+                    }
+                }
+                v => this_kind.push(v.clone()),
+            }
+        }
+        if !this_kind.is_empty() {
+            kinds.push(SelectorPart {
+                inner: std::mem::take(&mut this_kind),
+                is_invisible: false,
+                has_newline: false,
+                contains_super_selector: false,
+            });
+        }
+        Value::List(
+            kinds
+                .iter()
+                .map(|s| Value::Ident(s.to_string(), QuoteKind::None))
+                .collect(),
+            ListSeparator::Space,
+            Brackets::None,
+        )
+    }
+}
+
 impl Display for SelectorPart {
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
         let mut iter = self.inner.iter().peekmore();
@@ -562,4 +602,12 @@ impl Selector {
     pub fn contains_super_selector(&self) -> bool {
         self.0.iter().any(|s| s.contains_super_selector)
     }
+
+    pub fn into_value(&self) -> Value {
+        Value::List(
+            self.0.iter().map(SelectorPart::into_value).collect(),
+            ListSeparator::Comma,
+            Brackets::None,
+        )
+    }
 }

src/value/parse.rs

@@ -670,7 +670,7 @@ impl Value {
             '&' => {
                 let span = toks.next().unwrap().pos();
                 Ok(IntermediateValue::Value(Spanned {
-                    node: Value::Ident(super_selector.to_string(), QuoteKind::None),
+                    node: super_selector.into_value(),
                     span,
                 }))
             }

tests/selectors.rs

@@ -427,3 +427,83 @@ test!(
     ":not(%b) {x: y}",
     "* {\n  x: y;\n}\n"
 );
+test!(
+    interpolated_super_selector_in_style,
+    "a {\n  color: #{&};\n}\n",
+    "a {\n  color: a;\n}\n"
+);
+test!(
+    interpolated_super_selector_in_style_symbols,
+    "* .a #b:foo() {\n  color: #{&};\n}\n",
+    "* .a #b:foo() {\n  color: * .a #b:foo();\n}\n"
+);
+test!(
+    uninterpolated_super_selector,
+    "* .a #b:foo() {\n  color: &;\n}\n",
+    "* .a #b:foo() {\n  color: * .a #b:foo();\n}\n"
+);
+test!(
+    interpolated_super_selector_in_selector_and_style,
+    "a {\n  b #{&} {\n    color: &;\n  }\n}\n",
+    "a b a {\n  color: a b a;\n}\n"
+);
+test!(
+    super_selector_treated_as_list,
+    "a, b {\n  color: type-of(&);\n}\n",
+    "a, b {\n  color: list;\n}\n"
+);
+test!(
+    length_of_comma_separated_super_selector,
+    "a, b {\n  color: length(&);\n}\n",
+    "a, b {\n  color: 2;\n}\n"
+);
+test!(
+    nth_1_of_comma_separated_super_selector,
+    "a, b {\n  color: nth(&, 1);\n}\n",
+    "a, b {\n  color: a;\n}\n"
+);
+test!(
+    nth_2_of_comma_separated_super_selector,
+    "a, b {\n  color: nth(&, 2);\n}\n",
+    "a, b {\n  color: b;\n}\n"
+);
+test!(
+    length_of_space_separated_super_selector,
+    "a b {\n  color: length(&);\n}\n",
+    "a b {\n  color: 1;\n}\n"
+);
+test!(
+    nth_1_of_space_separated_super_selector,
+    "a b {\n  color: nth(&, 1);\n}\n",
+    "a b {\n  color: a b;\n}\n"
+);
+test!(
+    length_of_comma_separated_super_selector_has_compound,
+    "a:foo, b {\n  color: length(&);\n}\n",
+    "a:foo, b {\n  color: 2;\n}\n"
+);
+test!(
+    nth_1_of_comma_separated_super_selector_has_compound,
+    "a:foo, b {\n  color: nth(&, 1);\n}\n",
+    "a:foo, b {\n  color: a:foo;\n}\n"
+);
+test!(
+    length_of_space_separated_super_selector_has_compound,
+    "a:foo b {\n  color: length(&);\n}\n",
+    "a:foo b {\n  color: 1;\n}\n"
+);
+test!(
+    nth_1_of_space_separated_super_selector_has_compound,
+    "a:foo b {\n  color: nth(&, 1);\n}\n",
+    "a:foo b {\n  color: a:foo b;\n}\n"
+);
+test!(
+    length_super_selector_placeholder,
+    "a, %b {\n  color: length(&);\n}\n",
+    "a {\n  color: 2;\n}\n"
+);
+test!(
+    nth_2_super_selector_placeholder,
+    "a, %b {\n  color: nth(&, 2);\n}\n",
+    "a {\n  color: %b;\n}\n"
+);

tests/styles.rs

@@ -155,26 +155,6 @@ test!(
     styles_after_quoted,
     "a {\n  color: \"red\";\n  color: blue;\n}\n"
 );
-test!(
-    interpolated_super_selector_in_style,
-    "a {\n  color: #{&};\n}\n",
-    "a {\n  color: a;\n}\n"
-);
-test!(
-    interpolated_super_selector_in_style_symbols,
-    "* .a #b:foo() {\n  color: #{&};\n}\n",
-    "* .a #b:foo() {\n  color: * .a #b:foo();\n}\n"
-);
-test!(
-    uninterpolated_super_selector,
-    "* .a #b:foo() {\n  color: &;\n}\n",
-    "* .a #b:foo() {\n  color: * .a #b:foo();\n}\n"
-);
-test!(
-    interpolated_super_selector_in_selector_and_style,
-    "a {\n  b #{&} {\n    color: &;\n  }\n}\n",
-    "a b a {\n  color: a b a;\n}\n"
-);
 test!(
     emits_leading_whitespace,
     "a {\n  color: unquote(\" foo\");\n}\n",