1. TUBE TYPE: This may be one, two, or three alphanumerics or symbols.
管型：这可能是一个，两个或三个字母，数字或符号。
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2. By default, it matches only sequences of "keyword" characters (alphanumerics and underscore), and it has no deep sense of context beyond matching what's immediately to the left of the cursor.
3. By default, it matches only sequences of "keyword" characters (alphanumerics and underscore), and it has no deep sense of context beyond matching what's immediately to the left of the cursor.
