aichaos#87 Enlarge syntax check coverage to cover empty pipes

hungtu · hungtu · commit b5722d0fa310 · 2017-06-01T12:49:23.000+02:00
diff --git a/rivescript/parser.py b/rivescript/parser.py
@@ -549,6 +549,7 @@ def check_syntax(self, cmd, line):
             #   - Entirely lowercase
             #   - No symbols except: ( | ) [ ] * _ # @ { } < > =
             #   - All brackets should be matched
+            #   - No empty option with pipe such as ||, [|, |], (|, |) and whitespace between
             parens = 0  # Open parenthesis
             square = 0  # Open square brackets
             curly  = 0  # Open curly brackets
@@ -583,6 +584,11 @@ def check_syntax(self, cmd, line):
             elif angle != 0:
                 return "Unmatched angle brackets"
 
+            # Check for empty pipe
+            search = re.search(RE.empty_pipe, line)
+            if search:
+                return "Piped arrays can't include blank entries"
+
             # In UTF-8 mode, most symbols are allowed.
             if self.utf8:
                 search = re.search(RE.utf8_trig, line)
diff --git a/rivescript/regexp.py b/rivescript/regexp.py
@@ -48,3 +48,4 @@ class RE(object):
     placeholder = re.compile(r'\x00(\d+)\x00')
     zero_star   = re.compile(r'^\*$')
     optionals   = re.compile(r'\[(.+?)\]')
+    empty_pipe   = re.compile(r'\|\s*\||\[\s*\||\|\s*\]|\(\s*\||\|\s*\)')  # ||, [|, |], (|, |)
