Handle case where Word(min > 1) (fixes #502)

CHANGES

@@ -15,6 +15,8 @@ Version 3.2.0 will also discontinue support for Python versions 3.6 and 3.7.
 
 Version 3.1.1 - (in development)
 --------------------------------
+- Fixed bug in Word(min), reported by Ricardo Coccioli, good catch! (Issue #502)
+
 - Fixed bug in bad exception messages raised by Forward expressions. PR submitted
   by Kyle Sunden, thanks for your patience and collaboration on this (#493).
 

pyparsing/__init__.py

@@ -121,7 +121,7 @@ def __repr__(self):
 
 
 __version_info__ = version_info(3, 1, 1, "final", 1)
-__version_time__ = "29 Jul 2023 08:18 UTC"
+__version_time__ = "29 Jul 2023 09:56 UTC"
 __version__ = __version_info__.__version__
 __versionTime__ = __version_time__
 __author__ = "Paul McGuire <ptmcg.gm+pyparsing@gmail.com>"

pyparsing/core.py

@@ -1079,7 +1079,9 @@ def enable_left_recursion(
         ParserElement._left_recursion_enabled = True
 
     @staticmethod
-    def enable_packrat(cache_size_limit: Union[int, None] = 128, *, force: bool = False) -> None:
+    def enable_packrat(
+        cache_size_limit: Union[int, None] = 128, *, force: bool = False
+    ) -> None:
         """
         Enables "packrat" parsing, which adds memoizing to the parsing logic.
         Repeated parse attempts at the same string location (which happens
@@ -2879,7 +2881,7 @@ def __init__(
                 re_leading_fragment = f"[{_collapse_string_to_ranges(self.initChars)}]"
 
             if self.bodyChars == self.initChars:
-                if max == 0:
+                if max == 0 and self.minLen == 1:
                     repeat = "+"
                 elif max == 1:
                     repeat = ""

tests/test_unit.py

@@ -5221,6 +5221,50 @@ def testWordMinMaxExactArgs(self):
                     ["A1234567890"[:exarg]],
                 )
 
+    def testWordMin(self):
+        # failing tests
+        for min_val in range(2, 5):
+            with self.subTest(min_val=min_val):
+                wd = pp.Word("a", min=min_val)
+                print(min_val, wd.reString)
+                with self.assertRaisesParseException():
+                    wd.parse_string("a")
+
+        # passing tests
+        for min_val in range(2, 5):
+            with self.subTest(min_val=min_val):
+                wd = pp.Word("a", min=min_val)
+                test_string = "a" * min_val
+                self.assertParseAndCheckList(
+                    wd,
+                    test_string,
+                    [test_string],
+                    msg=f"Word(min={min_val}) failed",
+                    verbose=True,
+                )
+
+    def testWordExact(self):
+        # failing tests
+        for exact_val in range(2, 5):
+            with self.subTest(exact_val=exact_val):
+                wd = pp.Word("a", exact=exact_val)
+                print(exact_val, wd.reString)
+                with self.assertRaisesParseException():
+                    wd.parse_string("a")
+
+        # passing tests
+        for exact_val in range(2, 5):
+            with self.subTest(exact_val=exact_val):
+                wd = pp.Word("a", exact=exact_val)
+                test_string = "a" * exact_val
+                self.assertParseAndCheckList(
+                    wd,
+                    test_string,
+                    [test_string],
+                    msg=f"Word(exact={exact_val}) failed",
+                    verbose=True,
+                )
+
     def testInvalidMinMaxArgs(self):
         with self.assertRaises(ValueError):
             wd = pp.Word(min=2, max=1)
@@ -9915,8 +9959,10 @@ def testForwardReferenceException(self):
         text = pp.Word(pp.alphas)
         text.setName("text")
         fail = pp.Regex(r"\\[A-Za-z]*")("name")
+
         def parse_fail(s, loc, toks):
             raise pp.ParseFatalException(s, loc, f"Unknown symbol: {toks['name']}")
+
         fail.set_parse_action(parse_fail)
         token <<= num | text | fail