Macro in Vim

Introduction

Today, I wanted to change some parts of my code that had a repetitive sequence of actions. So, I thought it was a good idea to use macro in vim. Macro gives you the ability to record a sequence of actions and then repeat them as many times as you want.

My use-case

I had a code like below:

report["train"]["loss"] = metrics["loss"]
report["train"]["accuracy"] = metrics["accuracy"]
report["train"]["precision"] = metrics["precision"]
report["train"]["recall"] = metrics["recall"]
report["train"]["f1"] = metrics["f1"]

I wanted to change it to the code below:

report["train"]["loss"].append(metrics["loss"])
report["train"]["accuracy"].append(metrics["accuracy"])
report["train"]["precision"].append(metrics["precision"])
report["train"]["recall"].append(metrics["recall"])
report["train"]["f1"].append(metrics["f1"])

So what I did was, I started recording my macro by pressing these keys:

qa

• q: starts the recording
• a: the register that I write to

First thing that I am going to do is to go to the start of the line using ^. Then, I find the first space using f followed by a space ( ). After that, I press v and repeat the finding by pressing ;. Now, I have = selected. Then, I press s to delete them and enter the insert mode. Next, I type .append( and press Esc to enter the normal mode. After that, I type $ to go to the end of the line and type ). Then, I press j to go to the next line. And that is my macro. Now, if I type: :reg a, I would have something like below:

Type Name Content
c  "a   ^f v;s.append(^[$a)^[j

• c: stands for change
• "a: means register is saved in a
• ^f v;s.append(^[$a)^[j: is the sequence that we just did

To make the change, I only need to press @a to apply the changes that I want. Also, if I want, I can do 4@a for the 4 remaining lines that I have.

Final thoughts

Macro in vim is a powerful tool to do a sequence of events repetitively. I really enjoy using vim and I am planning to learn it better. But not going to lie, I think the AI assistants are going to replace these parts of vim very soon.