bundle: update (2026-01-18)

extensions/botbox3000/deps/tinycss2/nth.py

@@ -0,0 +1,100 @@
+import re
+
+from .parser import _next_significant, _to_token_iterator
+
+
+def parse_nth(input):
+    """Parse `<An+B> <https://drafts.csswg.org/css-syntax-3/#anb>`_,
+    as found in `:nth-child()
+    <https://drafts.csswg.org/selectors/#nth-child-pseudo>`_
+    and related Selector pseudo-classes.
+
+    Although tinycss2 does not include a full Selector parser,
+    this bit of syntax is included as it is particularly tricky to define
+    on top of a CSS tokenizer.
+
+    :type input: :obj:`str` or :term:`iterable`
+    :param input: A string or an iterable of :term:`component values`.
+    :returns:
+        A ``(a, b)`` tuple of integers, or :obj:`None` if the input is invalid.
+
+    """
+    tokens = _to_token_iterator(input, skip_comments=True)
+    token = _next_significant(tokens)
+    if token is None:
+        return
+    token_type = token.type
+    if token_type == 'number' and token.is_integer:
+        return parse_end(tokens, 0, token.int_value)
+    elif token_type == 'dimension' and token.is_integer:
+        unit = token.lower_unit
+        if unit == 'n':
+            return parse_b(tokens, token.int_value)
+        elif unit == 'n-':
+            return parse_signless_b(tokens, token.int_value, -1)
+        else:
+            match = N_DASH_DIGITS_RE.match(unit)
+            if match:
+                return parse_end(tokens, token.int_value, int(match.group(1)))
+    elif token_type == 'ident':
+        ident = token.lower_value
+        if ident == 'even':
+            return parse_end(tokens, 2, 0)
+        elif ident == 'odd':
+            return parse_end(tokens, 2, 1)
+        elif ident == 'n':
+            return parse_b(tokens, 1)
+        elif ident == '-n':
+            return parse_b(tokens, -1)
+        elif ident == 'n-':
+            return parse_signless_b(tokens, 1, -1)
+        elif ident == '-n-':
+            return parse_signless_b(tokens, -1, -1)
+        elif ident[0] == '-':
+            match = N_DASH_DIGITS_RE.match(ident[1:])
+            if match:
+                return parse_end(tokens, -1, int(match.group(1)))
+        else:
+            match = N_DASH_DIGITS_RE.match(ident)
+            if match:
+                return parse_end(tokens, 1, int(match.group(1)))
+    elif token == '+':
+        token = next(tokens)  # Whitespace after an initial '+' is invalid.
+        if token.type == 'ident':
+            ident = token.lower_value
+            if ident == 'n':
+                return parse_b(tokens, 1)
+            elif ident == 'n-':
+                return parse_signless_b(tokens, 1, -1)
+            else:
+                match = N_DASH_DIGITS_RE.match(ident)
+                if match:
+                    return parse_end(tokens, 1, int(match.group(1)))
+
+
+def parse_b(tokens, a):
+    token = _next_significant(tokens)
+    if token is None:
+        return (a, 0)
+    elif token == '+':
+        return parse_signless_b(tokens, a, 1)
+    elif token == '-':
+        return parse_signless_b(tokens, a, -1)
+    elif (token.type == 'number' and token.is_integer and
+          token.representation[0] in '-+'):
+        return parse_end(tokens, a, token.int_value)
+
+
+def parse_signless_b(tokens, a, b_sign):
+    token = _next_significant(tokens)
+    if (token.type == 'number' and token.is_integer and
+            token.representation[0] not in '-+'):
+        return parse_end(tokens, a, b_sign * token.int_value)
+
+
+def parse_end(tokens, a, b):
+    if _next_significant(tokens) is None:
+        return (a, b)
+
+
+N_DASH_DIGITS_RE = re.compile('^n(-[0-9]+)$')