beastbrook / arith-dsl

A simple arithmetic (external) DSL implemented in Scala

Arithmetic DSL

Compiling/Running

In order to compile and run the code, you need to install 'sbt'.

You can run the main file using the following command:

sbt run

Step 1

At this step, we implement the AST and parser for a simple arithmetic DSL with the following constructs:

1. addition, 2) substraction, and 3) a constant value.

Step 2

At this step, we define an interpreter for the DSL we have defined in the previous step.

Step 3

At this step, we extend the DSL with the following constructs: 4) multiplication, and 5) division.

Note how the AST, the parser, and the interpreter are modified to reflect the changes to the DSL.

Step 4

At this step, the DSL supports the definition of a (constant) variable. To define a variable we use the following syntax:

let x = e1 in e2

in which we initialize the variable named x with the expression e1. This variable can be used in the expression e2.

As an example, in the following program:

let x = 2 * 3 in x * 4

the variable x is initialized with the expression 2 * 3. This variable is then used in the expression x * 4. This program is evaluated to 24 in the run time.

Step 5

Finally, we add a C code generator for this DSL.