Syntax detection

Recognizing patterns in what the user types, and translating that into editing actions. For example, auto-markdown.

Notion.so auto-markdown

Facebook mentions

Pros

• Fast. In the flow of typing.
• No visual clutter. It's invisible.
• Contextual. Your action will affect where you type.

Cons

• Not discoverable. It's not common knowledge than one can type Markdown in a rich-text editor.
• Becomes hard to remember. Outside the most basic ones, a lot of people cannot remember how make an image link in Markdown for example.
• Limited coverage. This is pretty limited in term of expressivity. Making a table in Markdown starts to get hard. The more complex the pattern, the harder it is to type and remember.
• Conflicts. Can conflict with plain text writing. How do you write "@something" if the @ is taken for mentions?