feat(languages): pkl (#9515)

* feat(languages): pkl

Add [pkl](https://github.com/apple/pkl) language.
Official documentation: https://pkl-lang.org/

* remove branch indent

3 files changed, 232 insertions, 0 deletions

diff --git a/runtime/queries/pkl/highlights.scm b/runtime/queries/pkl/highlights.scm
new file mode 100644
index 00000000..501c9485
--- /dev/null
+++ b/runtime/queries/pkl/highlights.scm
@@ -0,0 +1,179 @@
+; Copyright © 2024 Apple Inc. and the Pkl project authors. All rights reserved.
+;
+; Licensed under the Apache License, Version 2.0 (the "License");
+; you may not use this file except in compliance with the License.
+; You may obtain a copy of the License at
+;
+;     https://www.apache.org/licenses/LICENSE-2.0
+;
+; Unless required by applicable law or agreed to in writing, software
+; distributed under the License is distributed on an "AS IS" BASIS,
+; WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+; See the License for the specific language governing permissions and
+; limitations under the License.
+
+; this definition is imprecise in that 
+; * any qualified or unqualified call to a method named "Regex" is considered a regex
+; * string delimiters are considered part of the regex
+
+; Operators
+
+[
+  "??"
+  "@"
+  "="
+  "<"
+  ">"
+  "!"
+  "=="
+  "!="
+  "<="
+  ">="
+  "&&"
+  "||"
+  "+"
+  "-"
+  "**"
+  "*"
+  "/"
+  "~/"
+  "%"
+  "|>"
+] @keyword.operator
+
+[
+  "?"
+  "|"
+  "->"
+] @operator.type
+
+[
+  ","
+  ":"
+  "."
+  "?."
+] @punctuation.delimiter
+
+[
+  "("
+  ")"
+  "]"
+  "{"
+  "}"
+  ; "[" @punctuation.bracket TODO: FIGURE OUT HOW TO REFER TO CUSTOM TOKENS
+] @punctuation.bracket
+
+; Keywords
+
+[
+  "abstract"
+  "amends"
+  "as"
+  "class"
+  "extends"
+  "external"
+  "function"
+  "hidden"
+  "import"
+  "import*"
+  "in"
+  "let"
+  "local"
+  "module"
+  "new"
+  "open"
+  "out"
+  "typealias"
+  "when"
+] @keyword
+
+[
+  "if"
+  "is"
+  "else"
+] @keyword.control.conditional
+
+[
+  "for"
+] @keyword.control.repeat
+
+(importExpr "import" @keyword.control.import)
+(importGlobExpr "import*" @keyword.control.import)
+
+"read" @function.builtin
+"read?" @function.builtin
+"read*" @function.builtin
+"throw" @function.builtin
+"trace" @function.builtin
+
+(moduleExpr "module" @type.builtin)
+"nothing" @type.builtin
+"unknown" @type.builtin
+
+(outerExpr) @variable.builtin
+"super" @variable.builtin
+(thisExpr) @variable.builtin
+
+[
+  (falseLiteral)
+  (nullLiteral)
+  (trueLiteral)
+] @constant.builtin
+
+; Literals
+
+(stringConstant) @string
+(slStringLiteral) @string
+(mlStringLiteral) @string
+
+(escapeSequence) @constent.character.escape
+
+(intLiteral) @constant.numeric.integer
+(floatLiteral) @constant.numeric.float
+
+(interpolationExpr
+  "\\(" @punctuation.special
+  ")" @punctuation.special) @embedded
+
+(interpolationExpr
+ "\\#(" @punctuation.special
+ ")" @punctuation.special) @embedded
+
+(interpolationExpr
+  "\\##(" @punctuation.special
+  ")" @punctuation.special) @embedded
+
+(lineComment) @comment
+(blockComment) @comment
+(docComment) @comment
+
+; Identifiers
+
+(classProperty (identifier) @variable.other.member)
+(objectProperty (identifier) @variable.other.member)
+
+(parameterList (typedIdentifier (identifier) @variable.parameter))
+(objectBodyParameters (typedIdentifier (identifier) @variable.parameter))
+
+(identifier) @variable
+
+; Method definitions
+
+(classMethod (methodHeader (identifier)) @function.method)
+(objectMethod (methodHeader (identifier)) @function.method)
+
+; Method calls
+
+(methodCallExpr
+  (identifier) @function.method)
+
+; Types
+
+(clazz (identifier) @type)
+(typeAlias (identifier) @type)
+((identifier) @type
+ (match? @type "^[A-Z]"))
+
+(typeArgumentList
+  "<" @punctuation.bracket
+  ">" @punctuation.bracket)
diff --git a/runtime/queries/pkl/indents.scm b/runtime/queries/pkl/indents.scm
new file mode 100644
index 00000000..d2a9be1a
--- /dev/null
+++ b/runtime/queries/pkl/indents.scm
@@ -0,0 +1,23 @@
+; Copyright © 2024 Apple Inc. and the Pkl project authors. All rights reserved.
+;
+; Licensed under the Apache License, Version 2.0 (the "License");
+; you may not use this file except in compliance with the License.
+; You may obtain a copy of the License at
+;
+;     https://www.apache.org/licenses/LICENSE-2.0
+;
+; Unless required by applicable law or agreed to in writing, software
+; distributed under the License is distributed on an "AS IS" BASIS,
+; WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+; See the License for the specific language governing permissions and
+; limitations under the License.
+
+; this definition is imprecise in that 
+; * any qualified or unqualified call to a method named "Regex" is considered a regex
+; * string delimiters are considered part of the regex
+[
+  (objectBody)
+  (classBody)
+  (ifExpr)
+  (mlStringLiteral) ; This isn't perfect; newlines are too indented but it's better than if omitted.
+] @indent
diff --git a/runtime/queries/pkl/injections.scm b/runtime/queries/pkl/injections.scm
new file mode 100644
index 00000000..15867f35
--- /dev/null
+++ b/runtime/queries/pkl/injections.scm
@@ -0,0 +1,30 @@
+; Copyright © 2024 Apple Inc. and the Pkl project authors. All rights reserved.
+;
+; Licensed under the Apache License, Version 2.0 (the "License");
+; you may not use this file except in compliance with the License.
+; You may obtain a copy of the License at
+;
+;     https://www.apache.org/licenses/LICENSE-2.0
+;
+; Unless required by applicable law or agreed to in writing, software
+; distributed under the License is distributed on an "AS IS" BASIS,
+; WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+; See the License for the specific language governing permissions and
+; limitations under the License.
+
+; this definition is imprecise in that 
+; * any qualified or unqualified call to a method named "Regex" is considered a regex
+; * string delimiters are considered part of the regex
+(
+  ((methodCallExpr (identifier) @methodName (argumentList (slStringLiteral) @injection.content))
+    (#set! injection.language "regex"))
+  (eq? @methodName "Regex"))
+ 
+((lineComment) @injection.content
+ (#set! injection.language "comment"))
+
+((blockComment) @injection.content
+ (#set! injection.language "comment"))
+
+((docComment) @injection.content
+ (#set! injection.language "markdown"))