Add support for Ballerina language (#1196)

languages.json

@@ -133,6 +133,14 @@
       "shebangs": ["#!/bin/awk -f"],
       "extensions": ["awk"]
     },
+    "Ballerina": {
+      "line_comment": ["//", "#"],
+      "quotes": [
+        ["\\\"", "\\\""],
+        ["`", "`"]
+      ],
+      "extensions": ["bal"]
+    },
     "Bash": {
       "name": "BASH",
       "shebangs": ["#!/bin/bash"],

tests/data/ballerina.bal

@@ -0,0 +1,40 @@
+// 40 lines 29 code 6 comments 5 blanks
+
+# Returns Bob's response to someone talking to him.
+#
+# + input - whatever is said to Bob
+# + return - Bob's response
+public function hey(string input) returns string {
+    string trimmed = input.trim();
+    boolean silent = isSilence(trimmed);
+    boolean asking = isQuestion(trimmed);
+    boolean yelling = isYelling(trimmed);
+
+    match [silent, yelling, asking] {
+        [true, _, _] => {
+            return "Fine. Be that way!";
+        }
+        [_, true, true] => {
+            return "Calm down, I know what I'm doing!";
+        }
+        [_, true, false] => {
+            return "Whoa, chill out!";
+        }
+        [_, false, true] => {
+            return "Sure.";
+        }
+        _ => {
+            return "Whatever.";
+        }
+    }
+}
+
+isolated function isSilence(string input) returns boolean => input.length() == 0;
+
+isolated function isQuestion(string input) returns boolean => input.endsWith("?");
+
+function isYelling(string input) returns boolean {
+    // contains an uppercase letter and does not contain a lowercase letter
+    return input.includesMatch(re `\p{Lu}`)
+        && !input.includesMatch(re `\p{Ll}`);
+}