Emacs

Clojure Journey III – Emacs for Beginners Course

Posted on by Otavio Valadares

On my last post I talked about why I chose Spacemacs to be my text editor while coding Clojure, installed it and made a nice first setup. In this post I’ll talk about some workflows/commands that I think is important to have a great and smooth coding.

This post probably will be one of these posts that keep opened in your browser and you read it everytime that you need to remember something.

Neotree

First let’s talk about our tree explorer, on the last post I installed the neotree that is similar to NERDTree(from vim), and started to using it.

The first thing that I did was to bind the open/close of it to F8 key with the fallowing code:

(global-set-key [f8] 'neotree-toggle)

Now just press F8 and your neotree will open.

Opening neotree

To navigate inside Neotree just use your moving keys (arrow keys or HJKL), if you have any question about it, you can just type ? and a nice window will be displayed with everything that you may need:

Neotree help page

And this image saved me from writing at least 500 words, this image has everything that you will need related to Neotree.

If you don’t want to open neotree with F8 you can open by pressing SPC + f + t.

Window

Split windows is a common move to every programmer, to split is easy, just press ESC to go back to visual mode (if not already), and press: SPC + w + / to split vertically or SPC + w + - to split horizontally, where SPC is your space key. If you don’t want to use SPC, M-m + number will work too.

M-<letter> stand for alt + m

Spliting Emacs Window

To navigate between window is simple, just press SPC and the number of the window that you want to go, like SPC + 2 to go to window 2. But how to know the window number?

Spacemacs window numberr

If you’re using spacemacs, your window number will be displayed by default on the bottom left corner of your window, as the pink arrows of the image is pointing. The current window will always be in different color (as the example, window 2).

Opening/Searching Files

Open using neotree

If you want to open a file inside a window, the easiest way is to open using Neotree, just go to the window that you want to have a file opened, open your neotree, navigate to the file and open it.

Opening file by Neotree
Project search aka Ctrl + P

But if you don’t want to search for the file in your neotree, you want something more like the famous ctrl + p command from other text editors? In spacemacs with helm (the setup that I’m using), it’s very simple, just type: SPC + p + f and a window will open, just write the name that you’re searching for, and press ENTER to open in the current window.

Searching for a file using spacemacs and helm projectile

Buffers

Now we know how to manage our windows, is time to understand and manage buffers! Technically… Windows displays emacs buffers!

Everything that you open inside emacs resides on what is called “buffer”, every code, really everything! And the plot is, if you close your file/window with the traditional :q! (if you use vim mode), this code isn’t close at all, the buffer still alive!

Too see your buffers just type C-c + b and a window will open with a list of all buffers.

C-c stands for ctrl + c.

List buffers

But this window is not very useful…If we want to open a buffer the best way is to use the buffer search (similar to the file search that we see previously), just press C-x + b and you’ll have a full interactive search for buffers:

Helm buffers find

Just search for the wanted buffer and press enter to open it. If you use C-c + o it will open in a splitted window. (If you just want to open in the current window, just type enter)

Search on spacemacs bufferr

A nice shortcut is to press SPC + tab to change to the last buffer!

All the buffers keep alive, ok! But how do we kill them? Just press C-x + k select the buffer and press enter!

Search on project

To search for a pattern across all the project is very easy, just type: SPC + / and start writing your pattern:

Global search spacemacs

If you press C-c + o like in other commands, it will open in a splitted window.

Replace

It has a nice built-in way to do search/replace inside project too, it ‘s simple, SPC + p + R (pay attention on capitalized R) . After this it will ask for a pattern to replace, and what to replace, after this it will open a window with the first match, press y if you want to replace and n if no. Do this for all matches.

Search and replace

Search for commands

Emacs comes with a global commands search, just type M-x` and write what you’re searching for.

OFF: Themes

If you want to install more themes is very easy! You can install a layer names themes-megapack (If you don’t know how to install layers read my last post) and you’ll have more than 100 themes to choose.

OFF: Games inside editor

Emacs comes with some games installed, just open the global search with M-x and write the name of one of the games, like, tetris!

Tetris on emacs

Remember: With great power comes great responsibility.

Conclusions

This is a short and beginner-friendly emacs tutorial with all flows that I think is important to get started in a new text editor.

I hope I haven’t forgotten anything important to get started with it.

On the next posts related to Clojure, I’ll be using my spacemacs as my text editor, I’m loving to use it and I want that everyone that trries to start using it, have a great experience too.

Final thought

If you have any questions that I can help you with, please ask! Send an email (otaviopvaladares at gmail.com), pm me on my Twitter or comment on this post!

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Clojure Journey II – Chose a editor

Posted on by Otavio Valadares

My second step through my journey to learn Clojure is to setup my text editor or IDE. I’m not a evangelist of any text editor or IDE, so I started to search for what people usually use or is best to use while coding Clojure. After few minutes and several posts around the internet, I noticed the four most indicated tools:

I started to try each one.. First I removed Cursive + IntelliJ from my options because cursive is a paid plugin, and I didn’t tried it at all. Then I tried to install Nightcode, it looks amazing, but I don’t like to use IDEs, is my personal option and in a few cases I chose to use IDEs (Java and Go).

Update: @tanrax made a great comment in this post saying that Cursive plugin is free for open source contributors and students, if you’re one, check it!

Now I have two rivals text editors and I need to chose one. I started to take a look at fireplace plugin to vim, because I use my neovim on 80% of my hours of coding, but after installed it, I faced problems when trying to fix them.

Finally I decided to take a look at Emacs (Yes, it was my last option), I never tried it before because it looks scary at the first time. I’m learning a new language, why don’t learn a new editor? I give a chance to emacs and…. It looks amazing!

In this post I’ll describe my setup and how to use emacs to development with Clojure.

Emacs or Spacemacs?

If you already use emacs and have your custom setup you can skip this part aand use your setup.

But what about those who don’t use emacs?

Emacs or Spacemacs is a long discussion, and I don’t want to get on one side now. Simplifying, spacemacs is a “comunity-driven emacs” and it comes with a lot of configuration already made. If you chose to proceed with emacs you’ll spend a time searching for plugins and custom setups that are already done or easy done with space.

As I am a beginner user with emacs, I decided to proceed with spacemacs.

Installing Emacs

Before install spacemacs, first we need emacs installed.

To install emacs is very simple and they have a nice webpage with all the links needed. As a GNU/Linux user I just downloaded the tarball file of version 27.1, extracted it and compiled/installed it from the source using the traditional ./configure, make and make install. After this emacs is installed! 

$ emacs --version
GNU Emacs 27.1
Copyright (C) 2020 Free Software Foundation, Inc.
GNU Emacs comes with ABSOLUTELY NO WARRANTY.
You may redistribute copies of GNU Emacs
under the terms of the GNU General Public License.
For more information about these matters, see the file 
named COPYING.

If you have any trouble, you can see the INSTALL file that come with.

Installing spacemacs

Spacemacs have a beautiful website that need to be checked, but it has a nice README on github too.

As the date of this post, install spacemacs is very easy, just clone it in the correct directory:

git clone https://github.com/syl20bnr/spacemacs ~/.emacs.d

After this if you start your emacs, it should open spacemacs, and it will start to self setup. It will ask you some questions, but I chose the default one for every question, and selected the vim mode, to use vim bindings inside emacs. It helped me a lot, because I’m used to use vim.

Custom setup

Now you have a file named .spacemacs on your user directory, and this file is your configuration file, similar to other text editors.

The first thing that I noticed when I started it for the first time was the size of the font, it looks very small on my monitor. To change this is easy, open your .spacemacs file (Using your spacemacs, right?), and change your size:

dotspacemacs-default-font '("Source Code Pro"
                               :size 19
                               :weight normal
                               :width normal
                               :powerline-scale 1.1)

After this next time that you open spacemacs, your text size will be better.

Other thing that I missed from vim/nvim was the famous NERDTree plugin that is a file system explorer. Fortunately I found a layer named Neotree that is basically the same thing.

To install it is simple, as the documentation says, just add the layer name neotree to the dotspacemacs-configuration-layers list.

dotspacemacs-configuration-layers
   '(
     helm
     emacs-lisp
     neotree
     )

And if you want to open the tree pressing one ke, you can paste the fallowing code inside your config file:

(global-set-key [f8] 'neotree-toggle)

And if you like to have a system explorer looking like the vim’s one, just put this in your config file:

(setq neo-theme 'nerd)

And not, just reload your emacs:

The the only thing missing in our editor now is the Clojure support, and to install it is simple, just go to the same place where you installed the neotree layer, and write “clojure”, re-open your editor, and it’s done! The Clojure support for emacs is amazing and we’lll see in the next post!

What is spacemacs layers?

The first thing to clarify is that layers is a concept from spacemacs and not from emacs.

A layer can be defined as a collection of packages and it’s configuration required to make them work well with spacemacs and each other. You can easily find a open-source layer for almost everything that you’ll need (almost), but of course, you can make private layers too.

To install a layer is easy, just follow the same steps of this post: Add its name to dotspacemacs-configuration-layers list. You can check it’s documentation to learn how to use them.

Conclusions

In this post I chose my text editor that I’ll use when coding Clojure. On the next post we’ll talk about CIDER, The Clojure Interactive Development Environment for Emacs! And spoiler: It’s amazing.

Final thought

If you have any questions that I can help you with, please ask! Send an email (otaviopvaladares@gmail.com), pm me on my Twitter or comment on this post!