Add actions (#4)

generate_toc.py

@@ -0,0 +1,118 @@
+import dataclasses
+import re
+import sys
+from typing import List
+
+
+@dataclasses.dataclass()
+class Header:
+    name: str
+    level: int
+
+    @property
+    def slug(self):
+        text = self.name.replace(' ', '-')
+        # single chars that are removed
+        text = re.sub(r'[`~!@#$%^&*()+=<>?,./:;"\'|{}\[\]\\–—]', '', text)
+        # CJK punctuations that are removed
+        text = re.sub(r'[　。？！，、；：“”【】（）〔〕［］﹃﹄“”‘’﹁﹂—…－～《》〈〉「」]', '', text)
+        return text
+
+
+class TOCMaker:
+    def __init__(
+            self,
+            *,
+            max_depth=6,
+            link_prefix='',
+            indentation_size=2,
+            list_bullets=('-', '*', '+', '-'),
+            header_class=Header,
+    ):
+        self.max_depth = max_depth
+        self.link_prefix = link_prefix
+        self.indentation_size = indentation_size
+        self.list_bullets = list_bullets
+        self.header_class = header_class
+
+    def make(self, text):
+        headers = self._collect_headers(text)
+        return self._make_toc(headers)
+
+    def make_from_file(self, fp):
+        return self.make(fp.read())
+
+    def _collect_headers(self, text):
+        headers = []
+
+        code_blocks = 0
+        for line in text.splitlines():
+            line = line.strip()
+            code_blocks += line.count('```') % 2
+            if code_blocks % 2 == 0 and line.startswith('#'):
+                header = self._parse_header_from_line(line)
+                if header.level <= self.max_depth:
+                    headers.append(self._parse_header_from_line(line))
+
+        return headers
+
+    def _make_toc(self, headers: List[Header]):
+        toc = []
+        for header in headers:
+            indentation = ' ' * ((header.level - 1) * self.indentation_size)
+            bullet = self._get_bullet(header.level)
+            toc.append(f'{indentation}{bullet} [{header.name}]({self.link_prefix}#{header.slug})')
+        return '\n'.join(toc)
+
+    def _get_bullet(self, level):
+        if level > len(self.list_bullets):
+            return self.list_bullets[-1]
+        return self.list_bullets[level - 1]
+
+    def _parse_header_from_line(self, line):
+        level = 0
+        name = ''
+        for char in line:
+            if char == '#':
+                level += 1
+            else:
+                name = line[level + 1:].strip()
+                break
+
+        return self.header_class(
+            name=name,
+            level=level
+        )
+
+
+def paste_after(delimiter, content, text):
+    result = []
+    for line in text.splitlines():
+        if line.strip() != delimiter:
+            result.append(line)
+        else:
+            result.append(f'{delimiter}\n')
+            result.append(f'{content}\n')
+            return '\n'.join(result)
+
+    raise ValueError(f"Can't find delimiter '{delimiter}'")
+
+
+if __name__ == '__main__':
+    with open('questions.md') as fp:
+        maker = TOCMaker(link_prefix='questions.md/')
+        toc = maker.make_from_file(fp)
+
+    with open('README.md', 'r') as fp:
+        original = fp.read()
+        changed = paste_after('<!-- toc -->', toc, original)
+
+    if '--check' in sys.argv:
+        if original != changed:
+            print('Error')
+            sys.exit(1)
+    else:
+        with open('README.md', 'w') as fp:
+            fp.write(changed)
+
+    print('Done')