This program demonstrates how to make an interpreter for a programming language. It uses the "Gang of Four" Intepreter design pattern to implement a simple, Pascal-like language. It is written in C++ and compiles under Windows, Linux and MacOS.
- Linux and MacOS: type
make - Windows: use the Visual Studio project
interpreter <action> <filename>
Where action is /p to pretty-print or /e to execute
The grammar of the language is Pascal-like. Here is a sample program that prints the first 100 prime numbers.
This example is available in the "Samples" directory. You can run it by typing interpreter /e ../samples/compute_primes.txt (use backslashes for Windows)
primecount := 0
testprime := 1
while primecount < 100
begin
isprime := 1
factor := 2
while isprime and factor * factor < testprime + 1
begin
isprime := testprime mod factor <> 0
factor := factor + 1
end
if isprime = 1
begin
print testprime
primecount := primecount + 1
end
testprime := testprime + 1
end