COMP 212: Functional Programming

Zoom link

Any class zoom events will be in this meeting.

Help Sessions

Sunday evening (Timothy Stephenson), 7:30pm-9pm, Exley 109
Monday afternoon (Dan Licata), 2:50pm-4:30pm, Exley 72
Monday evening (Daniel Goldelman, Eric Sakkas), 7:30pm-9pm, Exley 121 (Oct 3, Nov 21: ESC184 (Woodhead Lounge))
Tuesday afternoon (Dan Licata), 1:20pm-2:40pm, Exley 150
Tuesday evening (Timothy Stephenson, Eric Sakkas), 7:30pm-9pm, 109
Thursday evening (Jocelyn Wang), 7:10-9pm, Exley 113

Labs

Lab 1: Wednesday, 1:20pm-2:40pm, Exley 638
Lab 2: Wednesday, 2:50pm-4:10pm, Exley 103 (ST Lab)

Handouts

Common recurrences

SML

To install smlnj:

Mac OS

These directions worked on Mac OS Catalina/Big Sur/Monterey.

Start the Terminal application by selecting it from your Applications folder or by typing Terminal into Spotlight.
If you are on the latest MacOS (Catalina, Big Sur, Monterey) and don't have strong preferences about what unix shell you use, run
```
	chsh -s /bin/bash
	
```
(then type your mac password and hit enter when prompted) to switch your default shell to BASH from the new default of zsh. If you do have strong preferences about using zsh, then you will need to add the equivalent of the lines below setting your PATH and smlnj alias to your zsh startup files.
Close the terminal and then open a new one.
In the terminal, run
```
          xcode-select --install 
```
Run the installer that pops up if one does; otherwise you already have the command line tools installed.
Install the Homebrew package manager according to the directions on that page. I.e. copy the script into the Terminal and run it. At the end of the installation, it might (maybe only on Apple Silicon computers?) tell you two lines to run in the terminal, like
```
          echo 'eval $(/opt/homebrew/bin/brew shellenv)' >> /Users/$USER/.bash_profile
          eval $(/opt/homebrew/bin/brew shellenv)
        
```
If it does, please do that. This sets some necessary environment variables, which point homebrew to the right location on your system. The location of the brew executable might be different than above on some systems (e.g. it might be /usr/local/bin/brew instead).
In the terminal, run
```
brew install rlwrap
```
.
In the terminal, run
```
brew install smlnj
```
.

In the terminal, run

echo 'export PATH="/usr/local/smlnj/bin:${PATH}"' >> ~/.bash_profile

In the terminal, run

echo 'alias smlnj="rlwrap sml"' >> ~/.bash_profile

Close and restart the terminal and you should be able to run smlnj to start SML.

Work arounds:

If you get an error that rlwrap is not found, on some versions of MacOS the problem is that homebrew isn't getting added to your bash path correctly. You can fix this with
```
echo 'export PATH="/opt/homebrew/bin:${PATH}"' >> ~/.bash_profile
       
```
and then starting a new terminal shell.
If when installing Homebrew you get an error fatal: Could not resolve HEAD to a revision, then running
```
         git -C $(brew --repository homebrew/core) checkout master
       
```
fixed this for one student.
If SML installed via homebrew but rlwrap is broken, you can try installing just rlwrap via macports:
1. Install MacPorts. Note: even though it says you need to install XCode, you probably don't (tested on Mojave). Then, in Terminal (to open Terminal, go to Applications/Utilities), run
```
sudo /opt/local/bin/port install rlwrap
```
  rlwrap is a utility that lets you use the left/right arrow keys to move around and use the up/down arrows to go through lines you have previously typed.
2. In the terminal, run
```
echo 'export PATH="/opt/local/bin:${PATH}"' >> ~/.bash_profile
        
```
3. Start a new terminal.
If that fails, you can try alternate directions that don't use homebrew.

Windows

These directions were tested on Windows 10. If you have an earlier version and this doesn't work, here are some old directions that might work.

Use this installer.
Install the VSCode editor and run SML in its terminal according to the directions below.
If you get an error that sml.bat is not found, first try restarting VSCode. If that doesn't fix it, run PowerShell as an administrator and execute this command to add SMLNJ to your path (assuming SML is installed in the default location):
```
       [Environment]::SetEnvironmentVariable("PATH", $Env:PATH + ";C:\Program Files (x86)\SMLNJ\bin", [EnvironmentVariableTarget]::Machine)
       
```
And then restart VSCode.

Text Editor

On a Mac, we recommend Atom or VSCode or Sublime Text or GNU emacs for editing SML source files. Atom and VSCode allow you to run a terminal inside of the editor, so you can run smlnj in there. emacs has a special mode for running SML code, but is less new-user-friendly. For Sublime, you can only run SML code from the separate Terminal application. On Windows, we recommend VSCode. You could instead use Atom if you want, but I don't know how to run SMLNJ inside of atom on windows, so you would have to run it in a separate PowerShell window.

VSCode

Install VSCode and start it.
On the left-hand side, you should see an icon that looks like three squares with one square sticking out. This is the place to install extensions. Install the following two extensions:
- vscode-better-sml
- Tomorrow and Tomorrow Night Theme from Microsoft. Click on this extension, and use the Set Color Theme button at the top to select one of the themes if it doesn't already prompt you to do so.
This should make colorful syntax highlighting work for SML code.
Create a folder for your COMP 212 work and select it via Open Folder... (Windows) or Add folder to Workspace... (Mac). You should put the .sml files you download from the course web site into this folder.
You can start a terminal in VSCode by using the Terminal / New Terminal menu option.
Type smlnj (Mac) or sml (Windows) to start SML.

Atom

Install Atom.
Install the language-sml package by going to Prefrences/Settings, choosing the Install tab, and then typing it in to the search box at the top.
You can run smlnj in the built-in Mac Terminal application, but you want a terminal in Atom, you can install the platformio-ide-terminal package. Then, you can start a terminal by going to Packages / platformio-ide-terminal / New Terminal...

Sublime Text

Sublime Text is available here; get version 4.

More specifically:

Download the installer for your operating system. On Windows, follow the instructions in the installer. On Mac, navigate to your downloads and open the .dmg file. A pop-up containing your local Applications folder and a Sublime Text application file. Drag the Sublime Text file into the Applications folder.
On Windows, you can open Sublime Text through the Start Menu. On Mac, you can open Sublime Text in one of three ways:
- Finder: Open a new Finder window, navigate to your Applications folder (it should be listed in the left-hand column) and double-click on Sublime Text.
- Terminal: In terminal, enter “cd /Applications ; open Sublime\ Text.app/“.
- Launchpad: Open Launchpad and search for Sublime Text.
You may want to put a shortcut to Sublime Text on your desktop/in your Dock.
Install Package Control: Go to the Tools menu, click on Command Pallet, and then type Install Package Control.
To get syntax highlighting, install the "SML (Standard ML)" package:
1. Press on Tools > Command Palette in the menu bar and search for “install package”, then press enter with Package Control: Install Package.
2. Search for “SML (Standard ML)” and press enter to install.
To use SML highlighting, you may now navigate to View > Syntax > SML.

Emacs

If you have Linux, you almost certainly have emacs installed. For Mac and Windows get:

To install SML syntax highlighting:

Make a software directory in your home directory (to do this in the terminal, run mkdir ~/software/).
Download sml-mode.tar and unzip it in your software directory (to find it outside the terminal, your software directory will be in software in your home directory on a Mac or in C:\cygwin\users\YOURNAME\software on Windows). This will create a directory ~/software/sml-mode-3.3-custom.
Open Emacs, type Control-x Control-f to open a file, and then edit the line at the bottom of the screen to
```
        Find file: ~/.emacs
```
and press enter. This is your emacs startup file.
Copy the the contents of dotemacs-win.txt (Windows) or dotemacs-mac.txt (Mac) into this file. On Windows, you will need to edit the first line, replacing YOURNAME with your Cygwin user name. NOTE: The windows file is untested; let me know if you have problems.
Save, close, and restart emacs.
When you open emacs again and open a file.sml, it will now color the syntax. Also, you can run SML inside emacs as follows:
- Control-c Control-b: load the current emacs buffer into the SML repl.
- Control-c Control-s: pop up a separate window with the SML repl.

Some emacs resources:

Start with this tutorial on getting started with emacs
To exit emacs, type Control-X, then Control-C. A prompt may appear asking you about saving any changes you made; if this happens, you will need to answer it before exiting.
The emacs wiki is the omnibus resource for emacs usage
Wikipedia has an article on the general history and culture of emacs, for the curious.

Vim

If you used vim in COMP 211 and like it, we recommend this sml mode.