LogoVM

LogoVM is an abstract stack machine, loosely inspired by JavaVM, designed to provide a simple runtime environment to teach the design and implementation of compilers.

The initial design of the LogoVM, and where its name came from, was to aid in the implementation of a Logo compiler, during a one semester undergraduate course, so it provides some higher level functions for drawing lines, or controlling a drawing cursor.

To achieve the original goal, all computation is done using a stack, using a small set of low-level instructions. There is also a "high level" heap memory, where data is stored as full objects, and not bytes, meaning that if a huge string is on the first heap slot, the second heap slot may hold and integer, and the third heap slot may have a float value. A runtime environment that allows easy implementation of turtle graphics is also provided.

A specification of the LogoVM can be found on docs/specs.md.

Usage

To run a program simply call logovm <program>.

Check logovm -h for available options.

Installation

You may install the logovm package through pip:

pip install logovm

Some extra options are available:

• graphic: add support for graphic output (using pillow)
• test: add dependencies for running automated tests
• lint: add dependencies to ensure minimum code quality
• dev: an alias that include lint and test

For example, when implementing a feature for LogoVM, you would use:

(virt_env) [repo/logovm] $ pip -e install .[dev]

It is strongly suggested that you use a Python virtual environment.