diff --git a/src/hcl/parser.py b/src/hcl/parser.py
index 2b07d04..834d9f7 100644
--- a/src/hcl/parser.py
+++ b/src/hcl/parser.py
@@ -330,7 +330,7 @@ def p_function_0(self, p):
             self.print_p(p)
 
         p[0] = p[1] + p[2] + self.flatten(p[3]) + p[4]
-
+        
     def p_function_1(self, p):
         '''
         function : IDENTIFIER LEFTPAREN listitems COMMA RIGHTPAREN
@@ -343,31 +343,11 @@ def p_function_1(self, p):
     def flatten(self, value):
         returnValue = ""
         if type(value) is dict:
-            returnValue += "{"
-            isFirstTime = True
-            for key in value:
-                if isFirstTime:
-                    isFirstTime = False
-                else:
-                    returnValue += ","
-                returnValue += key + ":" + self.flatten(value[key])
-            returnValue += "}"
+            returnValue = "{" + ",".join(key + ":" + self.flatten(value[key]) for key in value) + "}"
         elif type(value) is list:
-            isFirstTime = True
-            for v in value:
-                if isFirstTime:
-                    isFirstTime = False
-                else:
-                    returnValue += ","
-                returnValue += self.flatten(v)
+            returnValue = ",".join(self.flatten(v) for v in value)
         elif type(value) is tuple:
-            isFirstTime = True
-            for v in value:
-                if isFirstTime:
-                    isFirstTime = False
-                else:
-                    returnValue += ","
-                returnValue += self.flatten(v)
+            returnValue = " ".join(self.flatten(v) for v in value)
         else:
             returnValue = value
         return returnValue
@@ -400,13 +380,20 @@ def p_listitems_2(self, p):
                   | objectkey COMMA objectkey
                   | objectkey COMMA object
                   | objectkey COMMA list
-                  | objectkey COMMA IDENTIFIER ASTERISK_PERIOD IDENTIFIER
         '''
         if DEBUG:
             self.print_p(p)
         p[0] = [p[1], p[3]]
 
     def p_listitems_3(self, p):
+        '''
+        listitems : objectkey COMMA IDENTIFIER ASTERISK_PERIOD IDENTIFIER
+        '''
+        if DEBUG:
+            self.print_p(p)
+        p[0] = [p[1], p[3] + p[4] + p[5]]
+
+    def p_listitems_4(self, p):
         '''
         listitems : objectkey list
         '''
diff --git a/tests/fixtures/function.hcl b/tests/fixtures/function.hcl
new file mode 100644
index 0000000..c7c1ee5
--- /dev/null
+++ b/tests/fixtures/function.hcl
@@ -0,0 +1,7 @@
+data "resource" "object" {
+  vars = {
+    cluster_1         = join("\n", data.template_file.cluster_1.*.rendered)
+    cluster_2         = join("\n", data.template_file.cluster_2.*.rendered)
+    cluster_3         = format("name_%02d", count.index + 1)
+  }
+}
\ No newline at end of file
diff --git a/tests/fixtures/function.json b/tests/fixtures/function.json
new file mode 100644
index 0000000..6ccd8e9
--- /dev/null
+++ b/tests/fixtures/function.json
@@ -0,0 +1,13 @@
+{
+  "data": {
+    "resource": {
+      "object": {
+        "vars": {
+          "cluster_1": "join(\\n,data.template_file.cluster_1.*.rendered)",
+          "cluster_2": "join(\\n,data.template_file.cluster_2.*.rendered)",
+          "cluster_3": "format(name_%02d,count.index + 1)"
+        }
+      }
+    }
+  }
+}
\ No newline at end of file
diff --git a/tests/test_decoder.py b/tests/test_decoder.py
index 60fc071..d4ba6ce 100644
--- a/tests/test_decoder.py
+++ b/tests/test_decoder.py
@@ -23,6 +23,7 @@
     ('flat.hcl', None, {'foo': 'bar', 'Key': 7}),
     ('float.hcl', None, {'a': 1.02}),
     ('float.hcl', 'float.json', None),
+    ('function.hcl', 'function.json', None),
     ('multiline_bad.hcl', 'multiline.json', None),
     ('scientific.hcl', 'scientific.json', None),
     ('structure.hcl', 'structure_flat.json', None),
diff --git a/tests/test_load_dump.py b/tests/test_load_dump.py
new file mode 100644
index 0000000..5984541
--- /dev/null
+++ b/tests/test_load_dump.py
@@ -0,0 +1,99 @@
+#
+# These tests are taken from hcl/parse_test.go
+#
+
+from __future__ import print_function
+
+from os.path import join, dirname
+import hcl
+import json
+
+import pytest
+
+PARSE_FIXTURE_DIR = join(dirname(__file__), 'lex-fixtures')
+PARSE_FIXTURES = [
+    (
+        "assign_colon.hcl",
+        False,
+    ),
+    (
+        "comment.hcl",
+        False,
+    ),
+    (
+        "list_comma.hcl",
+        False,
+    ),
+    (
+        "list_of_maps.hcl",
+        False,
+    ),
+    (
+        "multiple.hcl",
+        False,
+    ),
+    (
+        "structure.hcl",
+        False,
+    ),
+    (
+        "structure_basic.hcl",
+        False,
+    ),
+    (
+        "structure_empty.hcl",
+        False,
+    ),
+    (
+        "complex.hcl",
+        False,
+    ),
+    (
+        "assign_deep.hcl",
+        False,
+    ),
+    (
+        "types.hcl",
+        False,
+    ),
+    (
+        "structure_comma.hcl",
+        False,
+    ),
+    (
+        "terraform0.12syntax.hcl",
+        False,
+    ),
+    (
+        "conditional_operator.hcl",
+        False,
+    ),
+]
+
+@pytest.mark.parametrize("hcl_fname,invalid", PARSE_FIXTURES)
+def test_parser_bytes(hcl_fname, invalid):
+    
+    with open(join(PARSE_FIXTURE_DIR, hcl_fname), 'rb') as fp:
+        
+        input = fp.read()
+        print(input)
+        
+        if not invalid:
+            hcl.loads(input)
+        else:
+            with pytest.raises(ValueError):
+                hcl.loads(input)
+                
+@pytest.mark.parametrize("hcl_fname,invalid", PARSE_FIXTURES)
+def test_parser_str(hcl_fname, invalid):
+    
+    with open(join(PARSE_FIXTURE_DIR, hcl_fname), 'r') as fp:
+        
+        input = fp.read()
+        print(input)
+        
+        if not invalid:
+            hcl.loads(input)
+        else:
+            with pytest.raises(ValueError):
+                hcl.loads(input)