serene-simple/src/main/java/serene/simple/Main.java

package serene.simple;

import java.io.IOException;
import java.io.InputStreamReader;
import java.util.Scanner;
import java.io.BufferedReader;
import java.io.ByteArrayInputStream;
import java.io.Console;
import java.io.FileInputStream;


public class Main {
    public static void main(String[] args) throws IOException {
        if (args.length == 0) {
            startRepl();
            return;
        }
        runSerene(args[0]);
    }

    private static void startRepl() throws IOException {
        Scope rootScope = Scope.getRootScope();

        Console console = System.console();

        System.out.println("Serene 'simple' v0.1.0");
        while(true) {
            String inputData = console.readLine("serene-> ");

            if (inputData == null) break;

            ByteArrayInputStream inputStream = new ByteArrayInputStream(inputData.getBytes());
            ListNode<Node> nodes = Reader.read(inputStream);

            try {
                Object result = ListNode.EMPTY;
                for (Node n : nodes) {
                    result = n.eval(rootScope);
                }

                if (result != ListNode.EMPTY) {
                    System.out.print(";; ");
                    System.out.println(result);
                }
            }
            catch(Exception e) {
                System.out.println("Error: ");
                e.printStackTrace(System.out);
            }

        }
    }

    private static void runSerene(String filePath) throws IOException {
        Scope rootScope = Scope.getRootScope();

        ListNode<Node> nodes = Reader.read(new FileInputStream(filePath));

        for (Node n : nodes) {
            n.eval(rootScope);
        }
    }
}