Does an interpreter produce machine code

compilerinterpreters

I study the topics of compilers and interpreters intensively. I want to check if my base understanding is right, so let's assume the following:

I have a language called "Foobish" and its keywords are

<OUTPUT> 'TEXT', <Number_of_Repeats>;

So if I want to print to the console 10 times, I would write

OUTPUT 'Hello World', 10;

Hello World.foobish-file.

Now I write an interpreter in the language of my choice – C# in this case:

using System;

namespace FoobishInterpreter
{
    internal class Program
    {
        private static void Main(string[] args)
        {
            analyseAndTokenize(Hello World.foobish-file)//Pseudocode
            int repeats = Token[1];
            string outputString = Token[0];
            for (var i = 0; i < repeats; i++)
            {
                Console.WriteLine(outputString);
            }
        }
    }
}

On a very easy interpreter level, the interpreter would analyze the script-file, etc. and execute the foobish-language in the way of the interpreter's implementation.

Would a compiler create machine language which runs on the physical hardware directly?

So an interpreter doesn't produce machine language, but does a compiler do it for its input?

Do I have any misunderstandings in the basic way how compilers and interpreters work?

Best Answer

The terms "interpreter" and "compiler" are much more fuzzy than they used to be. Many years ago it was more common for compilers to produce machine code to be executed later, while interpreters more or less "executed" the source code directly. So those two terms were well understood back then.

But today there are many variations on the use of "compiler" and "interpreter." For example, VB6 "compiles" to byte code (a form of Intermediate Language), which is then "interpreted" by the VB Runtime. A similar process takes place in C#, which produces CIL that is then executed by a Just-In-Time Compiler (JIT) which, in the old days, would have been thought of as an interpreter. You can "freeze-dry" the output of the JIT into an actual binary executable by using NGen.exe, the product of which would have been the result of a compiler in the old days.

So the answer to your question is not nearly as straightforward as it once was.

Further Reading
Compilers vs. Interpreters on Wikipedia

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