Add regex for interpolator identifier

Fixes #222

Author: nicolasstucki

src/typescript/Scala.tmLanguage.ts

@@ -17,6 +17,7 @@ const idrest = `${letter}${letterOrDigit}*(?:(?<=_)${opchar}+)?`
 const idUpper = `${upperLetter}${letterOrDigit}*(?:(?<=_)${opchar}+)?`
 const idLower = `${lowerLetter}${letterOrDigit}*(?:(?<=_)${opchar}+)?`
 const plainid = `(?:${idrest}|${opchar}+)`
+const interpolatorid = `(?:${letter}${letterOrDigit}*(?:(?<=_)${opchar}+)?)`
 const backQuotedId = "`[^`]+`"
 const anyId = `(?:${plainid}|${backQuotedId})`
 const endOfLineMaybeWithComment = "(?=\\s*(//.*|/\\*(?!.*\\*/\\s*\\S.*).*)?$)"
@@ -365,7 +366,7 @@ export const scalaTmLanguage: TmLanguage = {
           }
         },
         {
-          begin: `\\b(${alphaId})(""")`,
+          begin: `\\b(${interpolatorid})(""")`,
           end: `(""")(?!")|\\$\n|(\\$[^\\$"_{${letterChars}])`,
           beginCaptures: {
             '1': {
@@ -456,7 +457,7 @@ export const scalaTmLanguage: TmLanguage = {
           }
         },
         {
-          begin: `\\b(${alphaId})(")`,
+          begin: `\\b(${interpolatorid})(")`,
           end: `(")|\\$\n|(\\$[^\\$"_{${letterChars}])`,
           beginCaptures: {
             '1': {

tests/unit/#222.test.scala

@@ -0,0 +1,33 @@
+// SYNTAX TEST "source.scala"
+
+   test"hello $name"
+// ^^^^ keyword.interpolation.scala
+//     ^ string.quoted.double.interpolated.scala punctuation.definition.string.begin.scala
+//      ^^^^^^ string.quoted.double.interpolated.scala
+//            ^ meta.template.expression.scala punctuation.definition.template-expression.begin.scala
+//             ^^^^ meta.template.expression.scala
+//                 ^ string.quoted.double.interpolated.scala punctuation.definition.string.end.scala
+
+   test1"hello $name"
+// ^^^^^ keyword.interpolation.scala
+//      ^ string.quoted.double.interpolated.scala punctuation.definition.string.begin.scala
+//       ^^^^^^ string.quoted.double.interpolated.scala
+//             ^ meta.template.expression.scala punctuation.definition.template-expression.begin.scala
+//              ^^^^ meta.template.expression.scala
+//                  ^ string.quoted.double.interpolated.scala punctuation.definition.string.end.scala
+
+   test1a"hello $name"
+// ^^^^^^ keyword.interpolation.scala
+//       ^ string.quoted.double.interpolated.scala punctuation.definition.string.begin.scala
+//        ^^^^^^ string.quoted.double.interpolated.scala
+//              ^ meta.template.expression.scala punctuation.definition.template-expression.begin.scala
+//               ^^^^ meta.template.expression.scala
+//                   ^ string.quoted.double.interpolated.scala punctuation.definition.string.end.scala
+
+   test_+"hello $name"
+// ^^^^^^ keyword.interpolation.scala
+//       ^ string.quoted.double.interpolated.scala punctuation.definition.string.begin.scala
+//        ^^^^^^ string.quoted.double.interpolated.scala
+//              ^ meta.template.expression.scala punctuation.definition.template-expression.begin.scala
+//               ^^^^ meta.template.expression.scala
+//                   ^ string.quoted.double.interpolated.scala punctuation.definition.string.end.scala