Support for replace with regexp

This PR addresses issues schibsted#346 and schibsted#347.

core/src/main/java/com/schibsted/spt/data/jslt/impl/BuiltinFunctions.java

@@ -104,6 +104,7 @@ public class BuiltinFunctions {
     functions.put("from-json", new BuiltinFunctions.FromJson());
     functions.put("to-json", new BuiltinFunctions.ToJson());
     functions.put("replace", new BuiltinFunctions.Replace());
+    functions.put("replace-regexp", new BuiltinFunctions.ReplaceRegexp());
     functions.put("trim", new BuiltinFunctions.Trim());
     functions.put("uuid", new BuiltinFunctions.Uuid());
 
@@ -961,6 +962,32 @@ else if (pos < string.length())
     }
   }
 
+  // ===== REPLACE-REGEXP
+
+  public static class ReplaceRegexp extends AbstractRegexpFunction {
+
+    public ReplaceRegexp() {
+      super("replace-regexp", 3, 3);
+    }
+
+    public JsonNode call(JsonNode input, JsonNode[] arguments) {
+      int args = null == arguments ? 0 : arguments.length;
+      if (args != 3) {
+        throw new JsltException("ReplaceRegexp requires 3 arguments, only " + args + " provided!");
+      }
+
+      String string = NodeUtils.toString(arguments[0], true);
+      if (string == null)
+        return NullNode.instance;
+
+      String regexp = NodeUtils.toString(arguments[1], false);
+      String replacement = NodeUtils.toString(arguments[2], false);
+      String result = !string.matches(regexp) ? string : string.replaceAll(regexp, replacement);
+
+      return new TextNode(result);
+    }
+  }
+
   // ===== TRIM
 
   public static class Trim extends AbstractFunction {

core/src/test/resources/function-tests.json

@@ -1127,6 +1127,16 @@
       "input" : "\"some text\"",
       "output": "\"\""
    },
+   {
+      "query": "replace-regexp(., \"([0-9][0-9][0-9][0-9])-([0-9][0-9])-([0-9][0-9])\", \"$2/$3/$1\")",
+      "input" : "\"2019-12-31\"",
+      "output": "\"12/31/2019\""
+   },
+   {
+      "query": "replace-regexp(., \"(?<year>[0-9][0-9][0-9][0-9])-(?<month>[0-9][0-9])-(?<day>[0-9][0-9])\", \"${day}.${month}.${year}\")",
+      "input" : "\"2019-12-31\"",
+      "output": "\"31.12.2019\""
+   },
    {
       "query": "trim(.)",
       "input" : "\"some text\"",