add python like cli interface

1 files changed, 22 insertions, 6 deletions

diff --git a/Calculator.java b/Calculator.java
index 7070c87..c43ca9f 100644
--- a/Calculator.java
+++ b/Calculator.java
@@ -1,14 +1,30 @@
+import java.util.Scanner;
+
 public class Calculator {
     public static void main(String[] args) {
-        GFrame frame = new GFrame("Calculator");
-        String expr = "(84 / 4 * 3 - 9) * 2 + 1 / 5"; // 108.2
+        // String expr = "(84 / 4 * 3 - 9) * 2 + 1 / 5"; // 108.2
+        String expr = new String(" ");
+        Scanner sc = new Scanner(System.in);
         Parser p;
+
         if (args.length == 0) {
-            p = new Parser(expr);
+            new GFrame("Calculator");
         } else {
-            p = new Parser(args[0]);
+            if (args[0].equals("-n")) {
+                System.out.println("Type \"exit\" or Ctrl+C to exit.");
+                while (true) {
+                    System.out.print(">>> ");
+                    expr = sc.nextLine();
+                    if (!expr.equals("exit")) {
+                        p = new Parser(expr);
+                        System.out.println(p.eval());
+                    } else {
+                        sc.close();
+                        break;
+                    }
+                }
+            } else {
+            }
         }
-        System.out.println("postfix => \t " + p.getPostfix());
-        System.out.println(p.eval());
     }
 }