Tau Programming Langugage

Tau is an experimental programming language created to explore how high-level langauge features can still allow fast numerical calculations. In particular, it will explore processor-level SIMD vectorization, aliasing guarantees (see Fortran or the restrict C keyword) and . It is a functional language using static, inferred typing. Programs can be compiled to an executable or run in a REPL environment, thanks to the LLVM compiler backend.

Because it is in a very early development stage, it is not reccommended for general use. Users should instead consider (depending on their needs) Julia, the C++ libraries Eigen or Armadillo, Python with Numpy, C, or Fortran.

Installation and Requirements

Tau requires that LLVM 3.7 be installed, which cannot be handled by setuptools. On Ubuntu based systems, this can be accomplished with the command sudo apt install llvm-3.7. The other requirements are Python packages listed in setup.py; setuptools will automatically install those requirements as needed. Download the source code directly or using git (command git clone https://github.com/dpthorngren/tau) and install it using setuptools python setup.py install --local (omit --local to install for all users). If all went well, you should be able to start Tau by typing tau into your terminal. See tau --help for usage information.

Syntax

The syntax is intentionally similar to Python, although many of the features are not fixed. Available types include Int, Real, Bool, and Array, with more planned. Here are a couple examples:

# Fibbonacci Numbers
def Int fibb(Int lim):
    a = 0
    b = 1
    temp = 0
    while a < lim:
        temp = a + b
        b = a
        a = temp
    a

# Compute pi inefficiently (Gregory-Leibniz Series)
def Real computePi(Int n):
    piApprox = 0.
    for i in range(n):
        piApprox += 4*(-1)**i / (2*i+1)
    piApprox

Development Status

Completed does not mean bug-free, unfortunately.

Completed Features:

• Int, Real, and Bool types
• if, while, and print
• Functions
• Simple Arrays
• Calling C standard library routines
• Implicit block ending (no more end statement)

To Do:

• More unit tests (never enough)
• Char, String types
• True for loops (current is placeholder)
• Proper import system
• Vectorized array operations
• Explicit return statement (no more returning last output)
• Encapsulation (classes, but perhaps not fully object-oriented)