Add support for kdl files

languages.json

@@ -918,6 +918,14 @@
       "quotes": [["\\\"", "\\\""], ["'", "'"]],
       "extensions": ["kak"]
     },
+    "KDL": {
+      "nested": true,
+      "line_comment": ["//"],
+      "multi_line_comments": [["/*", "*/"]],
+      "extensions": ["kdl"],
+      "quotes": [["\\\"", "\\\""], ["\\\"\\\"\\\"", "\\\"\\\"\\\""]],
+      "verbatim_quotes": [["#\\\"", "\\\"#"], ["#\\\"\\\"\\\"", "\\\"\\\"\\\"#"]]
+    },
     "Kotlin": {
       "line_comment": ["//"],
       "multi_line_comments": [["/*", "*/"]],

tests/data/kdl.kdl

@@ -0,0 +1,36 @@
+package {
+  name my-pkg
+  version "1.2.3"
+
+  dependencies {
+    // Nodes can have standalone values as well as
+    // key/value pairs.
+    lodash "^3.2.1" optional=#true alias=underscore
+  }
+
+  scripts {
+    // "Raw" and dedented multi-line strings are supported.
+    message """
+      hello
+      world
+      """
+    build #"""
+      echo "foo"
+      node -c "console.log('hello, world!');"
+      echo "foo" > some-file.txt
+      """#
+  }
+
+  // `\` breaks up a single node across multiple lines.
+  the-matrix 1 2 3 \
+             4 5 6 \
+             7 8 9
+
+  // "Slashdash" comments operate at the node level,
+  // with just `/-`.
+  /-this-is-commented {
+    this entire node {
+      is gone
+    }
+  }
+}