If you find yourself repeatedly type some similar-structured text in Vim/Nvim, you need to ask yourself if there is a better way to do it.

Snippet is a good way to insert structured text: you just need to type the trigger word and press the trigger key, then you have the whole text ready for you to edit. For example, when I am writing my blog post, I use meta as the trigger to generate the post front matter info.

Ultisnips is a good tool to automate text insertion, an it can increase your efficiency dramatically. For how to configure ultisnips for Neovim, refer to this post. In the following, I would like to show several cases of using snippet to improve my efficiency.

Generate debian change log file signature

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I saw a post on stackExchange that some one want to insert debian change file signature of the format:

-- Alexis Wilke <alexis@example.com>  Tue, 26 May 2020 18:00:09 -0800

Each time when he writes this signature, only the date changes. The date is also in standard format. This is good case to show how we can save our time with snippet.

We need create a file named debchangelog.snippets in our custom snippet directory and add the following snippet into it:

snippet debsig "debian change log signature" w
-- Alexis Wilke <alexis@example.com>  `!v strftime('%a, %d %b %Y %X %z')`
endsnippet

The backticked text use the interpolation feature of Ultisnips. !v means to use Vim language interpolation, and it should be followed by valid Vim script expressions, like the one given above.

After adding this snippet, when you open a debian changelog file¹, type debsig and press the trigger key, it will be expanded to the signature automatically.

Generate main function template for Python

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If a Python module can be imported and run as standard alone script, it is often a good practice to use the following template:

def main():
    # the main function logic here


if __name__ == "__main__":
    main()

It is cumbersome and time-wasting to type this every time we create a file. Let’s create a snippet for it. In the file python.snippet under your custom snippet directory, add the following snippet:

snippet main "Main function boilerplate" b
def main():
    $0


if __name__ == "__main__":
    main()
endsnippet

When you create a Python source file, type main and press trigger, the file template will be created automatically for you.

Insert center-aligned image in Markdown

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The default Markdown syntax for image can not align the image or set the image display size. We can use the raw HTML tag to achieve this:

<p align="center">
<img src="image_url" width="800">
</p>

To avoid typing these HTML tags every time, we can add the following image snippet to the file markdown.snippet under our custom snippet directory:

snippet img "Aligned image using HTML tag"
<p align="center">
<img src="${1:URL}" width="${2:800}">
</p>
$0
endsnippet

Then we can use img to trigger the image snippet. You can then press the forward jump and backward jump shortcut for Ultisnips to jump back and forth between the predefined stop positions to insert URL and adjust the image display size.