Because the code used in this book varies quite a bit, the steps needed to run it also vary. I'll list the general steps here (e.g. for JavaScript code, or Opa). More specific steps are found in each directory.
The directories are named according to how they occur in the book. For example, a JavaScript example that is in the "Composition and Modularity" section will be listed in the code examples under:
01/composition_and_modularity/composition.js
These are instructions to make sure the code that you're running is set up correctly. In most cases this will mean that you've installed the compiler and can compile and test the code.
I have made an effort to include a Makefile to help build any source code. If the relevant compilers are installed, just switching to the directory and running:
make
should build everything.
To run the JavaScript tests:
npm install
npm test
Be sure you have the Opa compiler installed. Installation instructions are found on the main Opalang site: http://opalang.org/.
Once you have a working Opa compiler, you can build an Opa program and then run it like this:
opa filename.opa
./filename.js
The Haskell code can be built using the Stack tool. Then just change into the appropriate directory and run:
stack build
stack exec <project_name>
to run the program.
Elm has a pre-built package for Mac OS X. You can find this on the website: http://elm-lang.org/Install.elm. For me this was as easy as just installing the package.
Once installed, you can build programs with elm-make (when there's not a Makefile):
elm-make Main.elm --output=main.html