Auto generate readme (#100)

* Auto generate readme provided by @KinglittleQ

auto-generate-readme.py

@@ -0,0 +1,89 @@
+from pathlib import Path
+
+
+class MarkdownParser():
+
+    def __init__(self, text):
+        self.text = text
+        self.lines = text.split('\n')
+
+    def title(self):
+        return self.lines[0].split(' ')[1]
+
+    def header(self, name, level, include_header=False):
+        start = False
+        end = False
+        content = []
+        mark = '#' * level
+        for line in self.lines:
+            if start and not end:
+                end |= (f'{mark} ' in line[:(level + 1)]) and (not f'{mark} {name}' in line)
+                if end:
+                    start = False
+                else:
+                    content.append(line)
+            else:
+                start = (f'{mark} {name}' in line)
+                if start:
+                    end = False
+                    if include_header:
+                        content.append(line)
+
+        content = '\n'.join(content)
+        return content
+
+    def overview(self):
+        overview = self.header('Overview', 2)
+        overview = overview.split('\n')
+        overview = '\n'.join(overview[1:])  # remove the first line
+        return overview
+
+    def features(self):
+        return self.header('C++', 2, True)
+
+
+def combine(text, parsers):
+    overview = ''
+    features = ''
+    title = ''
+    for p in parsers:
+        title += p.title().replace('C++', '') + '/'
+        overview += p.overview() + '\n'
+        features += p.features() + '\n'
+
+    title = title[:-1]
+    overview = overview.replace('README.md#', '#')
+    features = features.replace('README.md#', '#')
+
+    text = text.replace('# C++\n', f'# C++{title}\n')
+    text = text.replace(f'<!-- overview -->', overview)
+    text = text.replace(f'<!-- features -->', features)
+
+    return text
+
+
+def main():
+    src_dir = Path(__file__).parent
+    parsers = []
+
+    srcs = list(src_dir.glob('CPP*.md'))
+    srcs.sort(reverse=True)
+    for file in srcs:
+        with open(file, 'r') as fp:
+            text = fp.read()
+        p = MarkdownParser(text)
+        parsers.append(p)
+
+    template_file = src_dir / 'readme-template.md'
+    with open(template_file, 'r') as fp:
+        text = fp.read()
+
+    text = combine(text, parsers)
+
+    readme_file = src_dir / 'README.md'
+    with open(readme_file, 'w') as fp:
+        fp.write(text)
+
+
+if __name__ == '__main__':
+    main()