Introduce new semantic highlight token for format specifier

Author: ltentrup

crates/ra_ide/src/snapshots/highlight_injection.html

@@ -20,6 +20,7 @@
 .macro              { color: #94BFF3; }
 .module             { color: #AFD8AF; }
 .variable           { color: #DCDCCC; }
+.format_specifier   { color: #CC696B; }
 .mutable            { text-decoration: underline; }
 
 .keyword            { color: #F0DFAF; font-weight: bold; }

crates/ra_ide/src/snapshots/highlight_strings.html

@@ -20,6 +20,7 @@
 .macro              { color: #94BFF3; }
 .module             { color: #AFD8AF; }
 .variable           { color: #DCDCCC; }
+.format_specifier   { color: #CC696B; }
 .mutable            { text-decoration: underline; }
 
 .keyword            { color: #F0DFAF; font-weight: bold; }

crates/ra_ide/src/snapshots/highlighting.html

@@ -20,6 +20,7 @@
 .macro              { color: #94BFF3; }
 .module             { color: #AFD8AF; }
 .variable           { color: #DCDCCC; }
+.format_specifier   { color: #CC696B; }
 .mutable            { text-decoration: underline; }
 
 .keyword            { color: #F0DFAF; font-weight: bold; }

crates/ra_ide/src/snapshots/rainbow_highlighting.html

@@ -290,7 +290,7 @@ fn highlight_format_specifier(kind: FormatSpecifier) -> Option<HighlightTag> {
         | FormatSpecifier::DollarSign
         | FormatSpecifier::Dot
         | FormatSpecifier::Asterisk
-        | FormatSpecifier::QuestionMark => HighlightTag::Attribute,
+        | FormatSpecifier::QuestionMark => HighlightTag::FormatSpecifier,
         FormatSpecifier::Integer | FormatSpecifier::Zero => HighlightTag::NumericLiteral,
         FormatSpecifier::Identifier => HighlightTag::Local,
     })

crates/ra_ide/src/syntax_highlighting.rs

@@ -79,6 +79,7 @@ pre                 { color: #DCDCCC; background: #3F3F3F; font-size: 22px; padd
 .macro              { color: #94BFF3; }
 .module             { color: #AFD8AF; }
 .variable           { color: #DCDCCC; }
+.format_specifier   { color: #CC696B; }
 .mutable            { text-decoration: underline; }
 
 .keyword            { color: #F0DFAF; font-weight: bold; }

crates/ra_ide/src/syntax_highlighting/html.rs

@@ -39,6 +39,7 @@ pub enum HighlightTag {
     Union,
     Local,
     UnresolvedReference,
+    FormatSpecifier,
 }
 
 #[derive(Clone, Copy, Debug, PartialEq, Eq, Hash, PartialOrd, Ord)]
@@ -81,6 +82,7 @@ impl HighlightTag {
             HighlightTag::Union => "union",
             HighlightTag::Local => "variable",
             HighlightTag::UnresolvedReference => "unresolved_reference",
+            HighlightTag::FormatSpecifier => "format_specifier",
         }
     }
 }

crates/ra_ide/src/syntax_highlighting/tags.rs

@@ -25,7 +25,8 @@ use crate::{
     Result,
 };
 use semantic_tokens::{
-    ATTRIBUTE, BUILTIN_TYPE, ENUM_MEMBER, LIFETIME, TYPE_ALIAS, UNION, UNRESOLVED_REFERENCE,
+    ATTRIBUTE, BUILTIN_TYPE, ENUM_MEMBER, FORMAT_SPECIFIER, LIFETIME, TYPE_ALIAS, UNION,
+    UNRESOLVED_REFERENCE,
 };
 
 pub trait Conv {
@@ -381,6 +382,7 @@ impl Conv for Highlight {
             HighlightTag::Attribute => ATTRIBUTE,
             HighlightTag::Keyword => SemanticTokenType::KEYWORD,
             HighlightTag::UnresolvedReference => UNRESOLVED_REFERENCE,
+            HighlightTag::FormatSpecifier => FORMAT_SPECIFIER,
         };
 
         for modifier in self.modifiers.iter() {

crates/rust-analyzer/src/conv.rs

@@ -12,6 +12,7 @@ pub(crate) const TYPE_ALIAS: SemanticTokenType = SemanticTokenType::new("typeAli
 pub(crate) const UNION: SemanticTokenType = SemanticTokenType::new("union");
 pub(crate) const UNRESOLVED_REFERENCE: SemanticTokenType =
     SemanticTokenType::new("unresolvedReference");
+pub(crate) const FORMAT_SPECIFIER: SemanticTokenType = SemanticTokenType::new("formatSpecifier");
 
 pub(crate) const CONSTANT: SemanticTokenModifier = SemanticTokenModifier::new("constant");
 pub(crate) const CONTROL_FLOW: SemanticTokenModifier = SemanticTokenModifier::new("controlFlow");
@@ -46,6 +47,7 @@ pub(crate) const SUPPORTED_TYPES: &[SemanticTokenType] = &[
     TYPE_ALIAS,
     UNION,
     UNRESOLVED_REFERENCE,
+    FORMAT_SPECIFIER,
 ];
 
 pub(crate) const SUPPORTED_MODIFIERS: &[SemanticTokenModifier] = &[