diff --git a/.gitignore b/.gitignore
index d613bf7..45e325b 100644
--- a/.gitignore
+++ b/.gitignore
@@ -17,3 +17,5 @@ venv/
 .idea
 .venv
 tests/gen
+
+.claude
diff --git a/src/jsonata/functions.py b/src/jsonata/functions.py
index c3f29ad..d44b115 100644
--- a/src/jsonata/functions.py
+++ b/src/jsonata/functions.py
@@ -1836,7 +1836,8 @@ def each(obj: Optional[Mapping], func: Any) -> Optional[list]:
     #     
     @staticmethod
     def error(message: Optional[str]) -> NoReturn:
-        raise jexception.JException("D3137", -1, message if message is not None else "$error() function evaluated")
+        raise jexception.JException("D3137", -1,
+                                    message if message is not None else "$error() function evaluated")
 
     #
     #
@@ -1851,8 +1852,8 @@ def assert_fn(condition: Optional[bool], message: Optional[str]) -> None:
             raise jexception.JException("T0410", -1)
 
         if not condition:
-            raise jexception.JException("D3141", -1, "$assert() statement failed")
-            #                message: message || "$assert() statement failed"
+            raise jexception.JException("D3141", -1,
+                                        message if message is not None else "$assert() statement failed")
 
     #
     #
diff --git a/src/jsonata/jexception.py b/src/jsonata/jexception.py
index e0635d4..ab84242 100644
--- a/src/jsonata/jexception.py
+++ b/src/jsonata/jexception.py
@@ -105,6 +105,9 @@ def msg(error: str, location: int, arg1: Optional[Any], arg2: Optional[Any], det
 
         formatted = message
 
+        if formatted == "{{{message}}}":
+            return str(arg1)
+
         # Replace any {{var}} with format "{}"
         formatted = re.sub("\\{\\{\\w+\\}\\}", "{}", formatted)
 
diff --git a/src/jsonata/jsonata.py b/src/jsonata/jsonata.py
index 55476e0..ed99a66 100644
--- a/src/jsonata/jsonata.py
+++ b/src/jsonata/jsonata.py
@@ -469,7 +469,7 @@ def evaluate_tuple_step(self, expr: parser.Parser.Symbol, input: Optional[Sequen
         result.tuple_stream = True
         step_env = environment
         if tuple_bindings is None:
-            tuple_bindings = [{"@": item} for item in input if item is not None]
+            tuple_bindings = [{"@": item} for item in input]
 
         for tuple_binding in tuple_bindings:
             step_env = self.create_frame_from_tuple(environment, tuple_binding)
@@ -519,7 +519,7 @@ def evaluate_filter(self, predicate: Optional[Any], input: Optional[Any], enviro
             if index < 0:
                 # count in from end of array
                 index = len(input) + index
-            item = input[index] if index < len(input) else None
+            item = input[index] if 0 <= index < len(input) else None
             if item is not None:
                 if isinstance(item, list):
                     results = item
@@ -684,9 +684,6 @@ def evaluate_wildcard(self, expr: Optional[parser.Parser.Symbol], input: Optiona
                 if isinstance(value, list):
                     value = self.flatten(value, None)
                     results = functions.Functions.append(results, value)
-                elif isinstance(value, dict):
-                    # Call recursively do decompose the map
-                    results.extend(self.evaluate_wildcard(expr, value))
                 else:
                     results.append(value)
 
@@ -1475,7 +1472,14 @@ def apply_inner(self, proc: Optional[Any], args: Optional[Any], input: Optional[
             elif isinstance(proc, Jsonata.JLambda):
                 result = proc.call(input, validated_args)
             elif isinstance(proc, re.Pattern):
-                result = [s for s in validated_args if proc.search(s) is not None]
+                _res = []
+                for s in validated_args:
+                    if isinstance(s, str):
+                        _res.append(Jsonata._regex_closure(proc.finditer(s)))
+                if len(_res) == 1:
+                    result = _res[0]
+                else:
+                    result = _res
             else:
                 print("Proc not found " + str(proc))
                 raise jexception.JException("T1006", 0)
@@ -1489,6 +1493,19 @@ def apply_inner(self, proc: Optional[Any], args: Optional[Any], input: Optional[
             raise err
         return result
 
+    @staticmethod
+    def _regex_closure(iterator):
+        m = next(iterator, None)
+        if m is None:
+            return None
+        return {
+            "match": m.group(),
+            "start": m.start(),
+            "end": m.end(),
+            "groups": [m.group()],
+            "next": Jsonata.JLambda(lambda: Jsonata._regex_closure(iterator))
+        }
+
     #
     # Evaluate lambda against input data
     # @param {Object} expr - JSONata expression
diff --git a/src/jsonata/parser.py b/src/jsonata/parser.py
index d92a4c8..9385185 100644
--- a/src/jsonata/parser.py
+++ b/src/jsonata/parser.py
@@ -1047,7 +1047,8 @@ def process_ast(self, expr: Optional[Symbol]) -> Optional[Symbol]:
                 rest = self.process_ast(expr.rhs)
                 if (rest.type == "function" and rest.procedure.type == "path" and len(
                         rest.procedure.steps) == 1 and rest.procedure.steps[0].type == "name" and
-                        result.steps[-1].type == "function"):
+                        result.steps[-1].type == "function" and
+                        isinstance(rest.procedure.steps[0].value, Parser.Symbol)):
                     # next function in chain of functions - will override a thenable
                     result.steps[-1].next_function = rest.procedure.steps[0].value
                 if rest.type == "path":
diff --git a/src/jsonata/signature.py b/src/jsonata/signature.py
index 303a827..cd58c57 100644
--- a/src/jsonata/signature.py
+++ b/src/jsonata/signature.py
@@ -308,6 +308,7 @@ def validate(self, args: Any, context: Optional[Any]) -> Optional[Any]:
                             arg = args[arg_index] if arg_index < len(args) else None
                             validated_args.append(arg)
                             arg_index += 1
+                index += 1
             return validated_args
         self.throw_validation_error(args, supplied_sig, self.function_name)
 
diff --git a/src/jsonata/tokenizer.py b/src/jsonata/tokenizer.py
index 62027b7..0fad3db 100644
--- a/src/jsonata/tokenizer.py
+++ b/src/jsonata/tokenizer.py
@@ -137,7 +137,10 @@ def scan_regex(self) -> re.Pattern:
                 if pattern == "":
                     raise jexception.JException("S0301", self.position)
                 self.position += 1
-                current_char = self.path[self.position]
+                if self.position < self.length:
+                    current_char = self.path[self.position]
+                else:
+                    current_char = None
                 # flags
                 start = self.position
                 while current_char == 'i' or current_char == 'm':
diff --git a/src/jsonata/utils.py b/src/jsonata/utils.py
index eaab3e2..e886b18 100644
--- a/src/jsonata/utils.py
+++ b/src/jsonata/utils.py
@@ -74,11 +74,7 @@ def is_function(o: Optional[Any]) -> bool:
     @staticmethod
     def create_sequence(el: Optional[Any] = NONE) -> list:
         if el is not Utils.NONE:
-            if isinstance(el, list) and len(el) == 1:
-                sequence = Utils.JList(el)
-            else:
-                # This case does NOT exist in Javascript! Why?
-                sequence = Utils.JList([el])
+            sequence = Utils.JList([el])
         else:
             sequence = Utils.JList()
         sequence.sequence = True
diff --git a/tests/array_test.py b/tests/array_test.py
index d999c0a..1b01aae 100644
--- a/tests/array_test.py
+++ b/tests/array_test.py
@@ -1,7 +1,40 @@
 import jsonata
+import pytest
 
 
 class TestArray:
 
+    def test_negative_index(self):
+        expr = jsonata.Jsonata("item[-1]")
+        assert expr.evaluate({"item": []}) is None
+        expr = jsonata.Jsonata("$[-1]")
+        assert expr.evaluate([]) is None
+
     def test_array(self):
         assert jsonata.Jsonata("$.[{ }] ~> $reduce($append)").evaluate([True, True]) == [{}, {}]
+
+    def test_wildcard(self):
+        expr = jsonata.Jsonata("*")
+        assert expr.evaluate([{"x": 1}]) == {"x": 1}
+
+    def test_index(self):
+        expr = jsonata.Jsonata("($x:=['a','b']; $x#$i.$i)")
+        assert expr.evaluate(1) == [0, 1]
+        assert expr.evaluate(None) == [0, 1]
+
+    def test_wildcard_filter(self):
+        value1 = {"value": {"Name": "Cell1", "Product": "Product1"}}
+        value2 = {"value": {"Name": "Cell2", "Product": "Product2"}}
+        data = [value1, value2]
+
+        expression = jsonata.Jsonata("*[value.Product = 'Product1']")
+        assert expression.evaluate(data) == value1
+
+        expression2 = jsonata.Jsonata("**[value.Product = 'Product1']")
+        assert expression2.evaluate(data) == value1
+
+    def test_assert_custom_message(self):
+        expr = jsonata.Jsonata("$assert(false, 'custom error')")
+        with pytest.raises(jsonata.JException) as exc_info:
+            expr.evaluate(None)
+        assert "custom error" in str(exc_info.value)
diff --git a/tests/signature_test.py b/tests/signature_test.py
index 5a61532..53be04c 100644
--- a/tests/signature_test.py
+++ b/tests/signature_test.py
@@ -7,7 +7,7 @@ class TestSignature:
     def test_parameters_are_converted_to_arrays(self):
         expr = jsonata.Jsonata("$greet(1,null,3)")
         expr.register_function("greet", jsonata.Jsonata.JFunction(TestSignature.JFunctionCallable1(), "<a?a?a?a?:s>"))
-        assert expr.evaluate(None) == "[[1], [null], [3], [None]]"
+        assert expr.evaluate(None) == "[[1], None, [3], None]"
 
     class JFunctionCallable1(jsonata.Jsonata.JFunctionCallable):
 
@@ -30,3 +30,13 @@ class JFunctionCallable2(jsonata.Jsonata.JFunctionCallable):
 
         def call(self, input, args):
             return None
+
+    def test_var_arg_many(self):
+        expr = jsonata.Jsonata("$customArgs('test',[1,2,3,4],3)")
+        expr.register_function("customArgs", jsonata.Jsonata.JFunction(TestSignature.JFunctionCallable3(), "<sa<n>n:s>"))
+        assert expr.evaluate(None) == "['test', [1, 2, 3, 4], 3]"
+
+    class JFunctionCallable3(jsonata.Jsonata.JFunctionCallable):
+
+        def call(self, input, args):
+            return str(args)
diff --git a/tests/string_test.py b/tests/string_test.py
index 7eb4deb..76de5cb 100644
--- a/tests/string_test.py
+++ b/tests/string_test.py
@@ -42,6 +42,33 @@ def test_regex(self):
         assert (jsonata.Jsonata("($matcher := $eval('/^' & 'foo' & '/i'); $.$spread()[$.$keys() ~> $matcher])")
                 .evaluate({"foo": 1, "bar": 2}) == {"foo": 1})
 
+    def test_regex_literal(self):
+        expr = jsonata.Jsonata("/^test.*$/")
+        result = expr.evaluate(None)
+        assert result.pattern == "^test.*$"
+
+    def test_eval_regex(self):
+        expr = jsonata.Jsonata("$eval('/^test.*$/')")
+        result = expr.evaluate(None)
+        assert result.pattern == "^test.*$"
+
+    def test_eval_regex_check_answer_data(self):
+        expr = jsonata.Jsonata("(\n    $matcher := $eval('/l/');\n    ('Hello World' ~> $matcher);\n)")
+        result = expr.evaluate(None)
+        assert result["match"] == "l"
+        assert result["start"] == 2
+        assert result["end"] == 3
+        assert result["groups"] == ["l"]
+        assert callable(result["next"].function)
+
+    def test_eval_regex_call_next_and_check_result(self):
+        expr = jsonata.Jsonata("(\n    $matcher := $eval('/l/');\n    ('Hello World' ~> $matcher).next();\n)")
+        result = expr.evaluate(None)
+        assert result["match"] == "l"
+        assert result["start"] == 3
+        assert result["end"] == 4
+        assert result["groups"] == ["l"]
+
     #
     # Additional $split tests
     #   
@@ -84,6 +111,11 @@ def test_split(self):
         res = jsonata.Jsonata("$split('this.*.*is.*a.*test.*.*.*.*.*.*', /\\.\\*/, 8)").evaluate(None)
         assert res == ["this", "", "is", "a", "test", "", "", ""]
 
+    def test_fieldname_with_special_char(self):
+        expr = jsonata.Jsonata("$ ~> |$|{}|")
+        o = {"a\nb": "c\nd"}
+        assert expr.evaluate(o) == o
+
     def test_trim(self):
         assert jsonata.Jsonata("$trim(\"\n\")").evaluate(None) == ""
         assert jsonata.Jsonata("$trim(\" \")").evaluate(None) == ""