Move codespell:ignore check into Spellchecker

This makes the API automatically avoid some declared false-positives
that the command line tool would also filter.

codespell_lib/_codespell.py

@@ -59,7 +59,6 @@
     "(\\b(?:https?|[ts]?ftp|file|git|smb)://[^\\s]+(?=$|\\s)|"
     "\\b[\\w.%+-]+@[\\w.-]+\\b)"
 )
-inline_ignore_regex = re.compile(r"[^\w\s]\s?codespell:ignore\b(\s+(?P<words>[\w,]*))?")
 USAGE = """
 \t%prog [OPTIONS] [file1 file2 ... fileN]
 """
@@ -952,20 +951,10 @@ def parse_file(
         if not line or line in exclude_lines:
             continue
 
-        extra_words_to_ignore = set()
-        match = inline_ignore_regex.search(line)
-        if match:
-            extra_words_to_ignore = set(
-                filter(None, (match.group("words") or "").split(","))
-            )
-            if not extra_words_to_ignore:
-                continue
-
         fixed_words = set()
         asked_for = set()
 
-        issues = spellchecker.spellcheck_line(line, line_tokenizer, extra_words_to_ignore=extra_words_to_ignore)
-        for issue in issues:
+        for issue in spellchecker.spellcheck_line(line, line_tokenizer):
             misspelling = issue.misspelling
             word = issue.word
             lword = issue.lword

codespell_lib/spellchecker.py

@@ -21,6 +21,7 @@
 from typing import (
     Container,
     Dict,
+    FrozenSet,
     Generic,
     Iterable,
     Optional,
@@ -108,6 +109,8 @@
 
 _builtin_default_as_tuple = tuple(_builtin_default.split(","))
 
+_inline_ignore_regex = re.compile(r"[^\w\s]\s?codespell:ignore\b(\s+(?P<words>[\w,]*))?")
+
 
 class UnknownBuiltinDictionaryError(ValueError):
     def __init__(self, name: str) -> None:
@@ -173,12 +176,21 @@ def __init__(self) -> None:
         self._misspellings: Dict[str, Misspelling] = {}
         self.ignore_words_cased: Container[str] = frozenset()
 
+    def _parse_inline_ignore(self, line: str) -> Optional[FrozenSet[str]]:
+        inline_ignore_match = _inline_ignore_regex.search(line)
+        if inline_ignore_match:
+            words = frozenset(
+                filter(None, (inline_ignore_match.group("words") or "").split(","))
+            )
+            return words if words else None
+        return frozenset()
+
     def spellcheck_line(
         self,
         line: str,
         tokenizer: LineTokenizer[T_co],
         *,
-        extra_words_to_ignore: Container[str] = frozenset()
+        respect_inline_ignore: bool = True,
     ) -> Iterable[DetectedMisspelling[T_co]]:
         """Tokenize and spellcheck a line
 
@@ -187,12 +199,19 @@ def spellcheck_line(
 
         :param line: The line to spellcheck.
         :param tokenizer: A callable that will tokenize the line
-        :param extra_words_to_ignore: Extra words to ignore for this particular line
-          (such as content from a `codespell:ignore` comment)
+        :param respect_inline_ignore: Whether to check the line for
+           `codespell:ignore` instructions
+        :returns: An iterable of discovered typos.
         """
         misspellings = self._misspellings
         ignore_words_cased = self.ignore_words_cased
 
+        extra_words_to_ignore = (
+            self._parse_inline_ignore(line) if respect_inline_ignore else frozenset()
+        )
+        if extra_words_to_ignore is None:
+            return
+
         for token in tokenizer(line):
             word = token.group()
             if word in ignore_words_cased: