jonghough/tokamak

mini DSL language built with F# + FParsec

Tokamak

Advanced Fusion Reactor

Tokamak DSL

Tokamak DSL is a Domain Specific Language for .NET, written with FParsec parser combinator library.

Purpose

Tokamak can be embedded in .NET / mono applications (using .NET framework ~4.0+).

Evaluation

Expressions are evaluated right to left, with no operator precedence. Parentheses are used to evaluate subexpressions before the outer expression.

DataTypes

• Integer - corresponds to int64
• Floating - corresponds to double
• Literal - corresponds to string
• Bool - bool
• Array - This is an array of expressions, which may be datatypes or other expressions that can be evaluated to a datatype.

Functions

Functions are declared using function keyword followed by the function name, the parameters, the function body, and is terminated using the end keyword.

example

function fib(n)
  if n <= 1 then 1
  else
    n * fib(n-1)
  end
end

Array creation

Array declarations are simple:

myArray = 0$10 

This will create an array [0,1,...,9]. The contents of the array can be modified arbitrarily:

myArray[0] = 5.5

Controls

Tokamak has while-loops and for-loops, as well as if-elif-else blocks.

while loops

a = 0
ctr = "a"
while a < 10 do 
  a = a + 1
  ctr = ctr+"a" 
end

will produce the string aaaaaaaaaa.

for loops

function iseven(n) (n%2) = 0 end

arr = 0$100

for i in 0$100 do
  arr[i] = iseven(i)
end

arr

if-elseif-else control

a = 0$100
m0 = 0
m1 = 0
m2 = 0
for i in a do
  if 0 = i%3 then
    m0 = m0 + 1
  elseif 1 = i%3 then
    m1 = m1 + 1
  else m2 = m2 + 1
  end
end