Market

This is a multi-agent prototype to show a market modeled in Soda.

Where to start

Steps to run the example :

1. To run these steps, you need to install:
   • a. Scala 3
   • b. sbt (if you need to build the binaries)
   • c. Java (to execute JAR files)
   • d. Lean 4 (to verify the proofs)
   • e. Soda (to translate the examples)
2. Get the Soda translator binary by either doing the following:
   • a. download the Linux binary from releases
   • b. or clone the Soda repository and compile it, by either:
     • i. run bash makeall.sh, from a Linux compatible environment
     • ii. or run sbt to get an executable JAR file as indicated in the Soda release notes. The command itself is described in build and the file is release. To execute a JAR file, you need a Java environment installed, and you need to run java -jar filename.jar, for a JAR file named filename.jar.
   • c. make sure that the binary file soda is reachable from the command line, for example by updating the environment variable PATH.
3. Once you got the binary translator, go to an empty directory and try soda manual. It will output a piece of code with many examples, but most importantly, this mini-manual is a “Hello, World!” program itself. Write soda manual > Manual.soda and you get the manual.
4. To compile this project, run bash makeall.sh, from a Bash terminal. It creates a file named market and copies the example example0.yaml to the project root directory.
5. Try running ./market example0.yaml > example0Output.yaml, and modify its values, to test how it works. The supported operations are:
   • deposit user amount : declare a user account if necessary, and put money into the account;
   • assign item user : declare an item if necessary, and define its owner;
   • price item amount : define the price of an item, or hide it if its price is 0;
   • sell item user : exchange an item and its price between a buyer and a seller.
6. Try running the test instance generator with ./testInstanceGen 8000 13000 21000 > testExample.yaml. This creates an instance of a market with 8000 users, 13000 items, and 21000 transactions.
7. Try running the market with the test instance ./market testExample.yaml > testExampleOutput.yaml.
8. To translate the Soda files into Scala and Lean, and then compile the Lean files, run bash update.sh.
9. You can edit the Soda files with IntelliJ and compile them with the soda binary.
10. You can see and verify the Lean translations with Visual Studio Code. The translated files are in directory Soda, and in particular the package core.
11. The Bash script tester.sh tests the market with synthetic data. It requires to have market and testInstanceGen reachable in the path.

How to learn Soda

Soda is a functional language intended to be easy to learn and to read. However, writing purely functional style requires some practice, as some things are different from the imperative style. In addition, Soda includes an object-oriented notation to align it with mainstream object-oriented programming languages, and to make its notation familiar to users acquainted to those languages. For more details about Soda, see the Soda manual.

To get familiar with the verification possibilities, a good way to start proving theorems in Lean is to follow the tutorials at the Lean Game Server, like the Natural Number Game.

Build

The project can be built with sbt with sbt clean compile test package assembly

A Linux binary can be created with the script makeall.sh.

More detailed information can be found in the release notes.

Author

Julian Alfredo Mendez