Initial commit

5 files changed, 493 insertions, 0 deletions

diff --git a/src/java_cup/simple_calc/Main.java b/src/java_cup/simple_calc/Main.java
new file mode 100644
index 0000000..21ff5aa
--- /dev/null
+++ b/src/java_cup/simple_calc/Main.java
@@ -0,0 +1,32 @@
+// Driver for parser
+
+package java_cup.simple_calc;
+
+import java_cup.simple_calc.parser;
+import java_cup.runtime.Symbol;
+
+class Main {
+
+  static boolean do_debug_parse = false;
+
+  static public void main(String[] args) throws java.io.IOException {
+
+      /* create a parsing object */
+      parser parser_obj = new parser(new scanner());
+
+      /* open input files, etc. here */
+      Symbol parse_tree = null;
+
+      try {
+        if (do_debug_parse)
+          parse_tree = parser_obj.debug_parse();
+        else
+          parse_tree = parser_obj.parse();
+      } catch (Exception e) {
+        /* do cleanup here -- possibly rethrow e */
+      } finally {
+	/* do close out here */
+      }
+  }
+}
+
diff --git a/src/java_cup/simple_calc/parser.cup b/src/java_cup/simple_calc/parser.cup
new file mode 100644
index 0000000..a88d900
--- /dev/null
+++ b/src/java_cup/simple_calc/parser.cup
@@ -0,0 +1,55 @@
+// JavaCup specification for a simple expression evaluator (w/ actions)
+
+package java_cup.simple_calc;
+
+import java_cup.runtime.*;
+
+/* Terminals (tokens returned by the scanner). */
+terminal           SEMI, PLUS, MINUS, TIMES, DIVIDE, MOD;
+terminal           UMINUS, LPAREN, RPAREN;
+terminal Integer   NUMBER;
+
+/* Non terminals */
+non terminal Object     expr_list, expr_part;
+non terminal Integer    expr;
+
+/* Precedences */
+precedence left PLUS, MINUS;
+precedence left TIMES, DIVIDE, MOD;
+precedence left UMINUS, LPAREN;
+
+/* The grammar */
+expr_list ::= expr_list expr_part 
+	      | 
+              expr_part;
+
+expr_part ::= expr:e 
+	      {: System.out.println("= " + e); :} 
+              SEMI              
+	      ;
+
+expr      ::= expr:e1 PLUS expr:e2    
+	      {: RESULT = new Integer(e1.intValue() + e2.intValue()); :} 
+	      | 
+              expr:e1 MINUS expr:e2    
+              {: RESULT = new Integer(e1.intValue() - e2.intValue()); :} 
+	      | 
+              expr:e1 TIMES expr:e2 
+	      {: RESULT = new Integer(e1.intValue() * e2.intValue()); :} 
+	      | 
+              expr:e1 DIVIDE expr:e2 
+	      {: RESULT = new Integer(e1.intValue() / e2.intValue()); :} 
+	      | 
+              expr:e1 MOD expr:e2 
+	      {: RESULT = new Integer(e1.intValue() % e2.intValue()); :} 
+	      | 
+              NUMBER:n                 
+	      {: RESULT = n; :} 
+	      | 
+              MINUS expr:e             
+	      {: RESULT = new Integer(0 - e.intValue()); :} 
+	      %prec UMINUS
+	      | 
+              LPAREN expr:e RPAREN     
+	      {: RESULT = e; :} 
+	      ;
diff --git a/src/java_cup/simple_calc/parser.java b/src/java_cup/simple_calc/parser.java
new file mode 100644
index 0000000..d6003c7
--- /dev/null
+++ b/src/java_cup/simple_calc/parser.java
@@ -0,0 +1,318 @@
+
+//----------------------------------------------------
+// The following code was generated by CUP v0.10k
+// Sun Jul 25 13:36:02 EDT 1999
+//----------------------------------------------------
+
+package java_cup.simple_calc;
+
+import java_cup.runtime.*;
+
+/** CUP v0.10k generated parser.
+  * @version Sun Jul 25 13:36:02 EDT 1999
+  */
+public class parser extends java_cup.runtime.lr_parser {
+
+  /** Default constructor. */
+  public parser() {super();}
+
+  /** Constructor which sets the default scanner. */
+  public parser(java_cup.runtime.Scanner s) {super(s);}
+
+  /** Production table. */
+  protected static final short _production_table[][] = 
+    unpackFromStrings(new String[] {
+    "\000\015\000\002\003\004\000\002\002\004\000\002\003" +
+    "\003\000\002\006\002\000\002\004\005\000\002\005\005" +
+    "\000\002\005\005\000\002\005\005\000\002\005\005\000" +
+    "\002\005\005\000\002\005\003\000\002\005\004\000\002" +
+    "\005\005" });
+
+  /** Access to production table. */
+  public short[][] production_table() {return _production_table;}
+
+  /** Parse-action table. */
+  protected static final short[][] _action_table = 
+    unpackFromStrings(new String[] {
+    "\000\030\000\010\006\004\013\011\015\005\001\002\000" +
+    "\010\006\004\013\011\015\005\001\002\000\020\004\ufff7" +
+    "\005\ufff7\006\ufff7\007\ufff7\010\ufff7\011\ufff7\014\ufff7\001" +
+    "\002\000\012\002\uffff\006\uffff\013\uffff\015\uffff\001\002" +
+    "\000\016\004\ufffe\005\016\006\014\007\020\010\017\011" +
+    "\013\001\002\000\012\002\027\006\004\013\011\015\005" +
+    "\001\002\000\010\006\004\013\011\015\005\001\002\000" +
+    "\016\005\016\006\014\007\020\010\017\011\013\014\015" +
+    "\001\002\000\010\006\004\013\011\015\005\001\002\000" +
+    "\010\006\004\013\011\015\005\001\002\000\020\004\ufff5" +
+    "\005\ufff5\006\ufff5\007\ufff5\010\ufff5\011\ufff5\014\ufff5\001" +
+    "\002\000\010\006\004\013\011\015\005\001\002\000\010" +
+    "\006\004\013\011\015\005\001\002\000\010\006\004\013" +
+    "\011\015\005\001\002\000\020\004\ufffa\005\ufffa\006\ufffa" +
+    "\007\ufffa\010\ufffa\011\ufffa\014\ufffa\001\002\000\020\004" +
+    "\ufff9\005\ufff9\006\ufff9\007\ufff9\010\ufff9\011\ufff9\014\ufff9" +
+    "\001\002\000\020\004\ufffc\005\ufffc\006\ufffc\007\020\010" +
+    "\017\011\013\014\ufffc\001\002\000\020\004\ufffb\005\ufffb" +
+    "\006\ufffb\007\020\010\017\011\013\014\ufffb\001\002\000" +
+    "\020\004\ufff8\005\ufff8\006\ufff8\007\ufff8\010\ufff8\011\ufff8" +
+    "\014\ufff8\001\002\000\012\002\001\006\001\013\001\015" +
+    "\001\001\002\000\004\002\000\001\002\000\004\004\031" +
+    "\001\002\000\012\002\ufffd\006\ufffd\013\ufffd\015\ufffd\001" +
+    "\002\000\020\004\ufff6\005\ufff6\006\ufff6\007\ufff6\010\ufff6" +
+    "\011\ufff6\014\ufff6\001\002" });
+
+  /** Access to parse-action table. */
+  public short[][] action_table() {return _action_table;}
+
+  /** <code>reduce_goto</code> table. */
+  protected static final short[][] _reduce_table = 
+    unpackFromStrings(new String[] {
+    "\000\030\000\010\003\007\004\005\005\006\001\001\000" +
+    "\004\005\031\001\001\000\002\001\001\000\002\001\001" +
+    "\000\004\006\027\001\001\000\006\004\025\005\006\001" +
+    "\001\000\004\005\011\001\001\000\002\001\001\000\004" +
+    "\005\024\001\001\000\004\005\023\001\001\000\002\001" +
+    "\001\000\004\005\022\001\001\000\004\005\021\001\001" +
+    "\000\004\005\020\001\001\000\002\001\001\000\002\001" +
+    "\001\000\002\001\001\000\002\001\001\000\002\001\001" +
+    "\000\002\001\001\000\002\001\001\000\002\001\001\000" +
+    "\002\001\001\000\002\001\001" });
+
+  /** Access to <code>reduce_goto</code> table. */
+  public short[][] reduce_table() {return _reduce_table;}
+
+  /** Instance of action encapsulation class. */
+  protected CUP$parser$actions action_obj;
+
+  /** Action encapsulation object initializer. */
+  protected void init_actions()
+    {
+      action_obj = new CUP$parser$actions(this);
+    }
+
+  /** Invoke a user supplied parse action. */
+  public java_cup.runtime.Symbol do_action(
+    int                        act_num,
+    java_cup.runtime.lr_parser parser,
+    java.util.Stack            stack,
+    int                        top)
+    throws java.lang.Exception
+  {
+    /* call code in generated class */
+    return action_obj.CUP$parser$do_action(act_num, parser, stack, top);
+  }
+
+  /** Indicates start state. */
+  public int start_state() {return 0;}
+  /** Indicates start production. */
+  public int start_production() {return 1;}
+
+  /** <code>EOF</code> Symbol index. */
+  public int EOF_sym() {return 0;}
+
+  /** <code>error</code> Symbol index. */
+  public int error_sym() {return 1;}
+
+}
+
+/** Cup generated class to encapsulate user supplied action code.*/
+class CUP$parser$actions {
+  private final parser parser;
+
+  /** Constructor */
+  CUP$parser$actions(parser parser) {
+    this.parser = parser;
+  }
+
+  /** Method with the actual generated action code. */
+  public final java_cup.runtime.Symbol CUP$parser$do_action(
+    int                        CUP$parser$act_num,
+    java_cup.runtime.lr_parser CUP$parser$parser,
+    java.util.Stack            CUP$parser$stack,
+    int                        CUP$parser$top)
+    throws java.lang.Exception
+    {
+      /* Symbol object for return from actions */
+      java_cup.runtime.Symbol CUP$parser$result;
+
+      /* select the action based on the action number */
+      switch (CUP$parser$act_num)
+        {
+          /*. . . . . . . . . . . . . . . . . . . .*/
+          case 12: // expr ::= LPAREN expr RPAREN 
+            {
+              Integer RESULT = null;
+		int eleft = ((java_cup.runtime.Symbol)CUP$parser$stack.elementAt(CUP$parser$top-1)).left;
+		int eright = ((java_cup.runtime.Symbol)CUP$parser$stack.elementAt(CUP$parser$top-1)).right;
+		Integer e = (Integer)((java_cup.runtime.Symbol) CUP$parser$stack.elementAt(CUP$parser$top-1)).value;
+		 RESULT = e; 
+              CUP$parser$result = new java_cup.runtime.Symbol(3/*expr*/, ((java_cup.runtime.Symbol)CUP$parser$stack.elementAt(CUP$parser$top-2)).left, ((java_cup.runtime.Symbol)CUP$parser$stack.elementAt(CUP$parser$top-0)).right, RESULT);
+            }
+          return CUP$parser$result;
+
+          /*. . . . . . . . . . . . . . . . . . . .*/
+          case 11: // expr ::= MINUS expr 
+            {
+              Integer RESULT = null;
+		int eleft = ((java_cup.runtime.Symbol)CUP$parser$stack.elementAt(CUP$parser$top-0)).left;
+		int eright = ((java_cup.runtime.Symbol)CUP$parser$stack.elementAt(CUP$parser$top-0)).right;
+		Integer e = (Integer)((java_cup.runtime.Symbol) CUP$parser$stack.elementAt(CUP$parser$top-0)).value;
+		 RESULT = new Integer(0 - e.intValue()); 
+              CUP$parser$result = new java_cup.runtime.Symbol(3/*expr*/, ((java_cup.runtime.Symbol)CUP$parser$stack.elementAt(CUP$parser$top-1)).left, ((java_cup.runtime.Symbol)CUP$parser$stack.elementAt(CUP$parser$top-0)).right, RESULT);
+            }
+          return CUP$parser$result;
+
+          /*. . . . . . . . . . . . . . . . . . . .*/
+          case 10: // expr ::= NUMBER 
+            {
+              Integer RESULT = null;
+		int nleft = ((java_cup.runtime.Symbol)CUP$parser$stack.elementAt(CUP$parser$top-0)).left;
+		int nright = ((java_cup.runtime.Symbol)CUP$parser$stack.elementAt(CUP$parser$top-0)).right;
+		Integer n = (Integer)((java_cup.runtime.Symbol) CUP$parser$stack.elementAt(CUP$parser$top-0)).value;
+		 RESULT = n; 
+              CUP$parser$result = new java_cup.runtime.Symbol(3/*expr*/, ((java_cup.runtime.Symbol)CUP$parser$stack.elementAt(CUP$parser$top-0)).left, ((java_cup.runtime.Symbol)CUP$parser$stack.elementAt(CUP$parser$top-0)).right, RESULT);
+            }
+          return CUP$parser$result;
+
+          /*. . . . . . . . . . . . . . . . . . . .*/
+          case 9: // expr ::= expr MOD expr 
+            {
+              Integer RESULT = null;
+		int e1left = ((java_cup.runtime.Symbol)CUP$parser$stack.elementAt(CUP$parser$top-2)).left;
+		int e1right = ((java_cup.runtime.Symbol)CUP$parser$stack.elementAt(CUP$parser$top-2)).right;
+		Integer e1 = (Integer)((java_cup.runtime.Symbol) CUP$parser$stack.elementAt(CUP$parser$top-2)).value;
+		int e2left = ((java_cup.runtime.Symbol)CUP$parser$stack.elementAt(CUP$parser$top-0)).left;
+		int e2right = ((java_cup.runtime.Symbol)CUP$parser$stack.elementAt(CUP$parser$top-0)).right;
+		Integer e2 = (Integer)((java_cup.runtime.Symbol) CUP$parser$stack.elementAt(CUP$parser$top-0)).value;
+		 RESULT = new Integer(e1.intValue() % e2.intValue()); 
+              CUP$parser$result = new java_cup.runtime.Symbol(3/*expr*/, ((java_cup.runtime.Symbol)CUP$parser$stack.elementAt(CUP$parser$top-2)).left, ((java_cup.runtime.Symbol)CUP$parser$stack.elementAt(CUP$parser$top-0)).right, RESULT);
+            }
+          return CUP$parser$result;
+
+          /*. . . . . . . . . . . . . . . . . . . .*/
+          case 8: // expr ::= expr DIVIDE expr 
+            {
+              Integer RESULT = null;
+		int e1left = ((java_cup.runtime.Symbol)CUP$parser$stack.elementAt(CUP$parser$top-2)).left;
+		int e1right = ((java_cup.runtime.Symbol)CUP$parser$stack.elementAt(CUP$parser$top-2)).right;
+		Integer e1 = (Integer)((java_cup.runtime.Symbol) CUP$parser$stack.elementAt(CUP$parser$top-2)).value;
+		int e2left = ((java_cup.runtime.Symbol)CUP$parser$stack.elementAt(CUP$parser$top-0)).left;
+		int e2right = ((java_cup.runtime.Symbol)CUP$parser$stack.elementAt(CUP$parser$top-0)).right;
+		Integer e2 = (Integer)((java_cup.runtime.Symbol) CUP$parser$stack.elementAt(CUP$parser$top-0)).value;
+		 RESULT = new Integer(e1.intValue() / e2.intValue()); 
+              CUP$parser$result = new java_cup.runtime.Symbol(3/*expr*/, ((java_cup.runtime.Symbol)CUP$parser$stack.elementAt(CUP$parser$top-2)).left, ((java_cup.runtime.Symbol)CUP$parser$stack.elementAt(CUP$parser$top-0)).right, RESULT);
+            }
+          return CUP$parser$result;
+
+          /*. . . . . . . . . . . . . . . . . . . .*/
+          case 7: // expr ::= expr TIMES expr 
+            {
+              Integer RESULT = null;
+		int e1left = ((java_cup.runtime.Symbol)CUP$parser$stack.elementAt(CUP$parser$top-2)).left;
+		int e1right = ((java_cup.runtime.Symbol)CUP$parser$stack.elementAt(CUP$parser$top-2)).right;
+		Integer e1 = (Integer)((java_cup.runtime.Symbol) CUP$parser$stack.elementAt(CUP$parser$top-2)).value;
+		int e2left = ((java_cup.runtime.Symbol)CUP$parser$stack.elementAt(CUP$parser$top-0)).left;
+		int e2right = ((java_cup.runtime.Symbol)CUP$parser$stack.elementAt(CUP$parser$top-0)).right;
+		Integer e2 = (Integer)((java_cup.runtime.Symbol) CUP$parser$stack.elementAt(CUP$parser$top-0)).value;
+		 RESULT = new Integer(e1.intValue() * e2.intValue()); 
+              CUP$parser$result = new java_cup.runtime.Symbol(3/*expr*/, ((java_cup.runtime.Symbol)CUP$parser$stack.elementAt(CUP$parser$top-2)).left, ((java_cup.runtime.Symbol)CUP$parser$stack.elementAt(CUP$parser$top-0)).right, RESULT);
+            }
+          return CUP$parser$result;
+
+          /*. . . . . . . . . . . . . . . . . . . .*/
+          case 6: // expr ::= expr MINUS expr 
+            {
+              Integer RESULT = null;
+		int e1left = ((java_cup.runtime.Symbol)CUP$parser$stack.elementAt(CUP$parser$top-2)).left;
+		int e1right = ((java_cup.runtime.Symbol)CUP$parser$stack.elementAt(CUP$parser$top-2)).right;
+		Integer e1 = (Integer)((java_cup.runtime.Symbol) CUP$parser$stack.elementAt(CUP$parser$top-2)).value;
+		int e2left = ((java_cup.runtime.Symbol)CUP$parser$stack.elementAt(CUP$parser$top-0)).left;
+		int e2right = ((java_cup.runtime.Symbol)CUP$parser$stack.elementAt(CUP$parser$top-0)).right;
+		Integer e2 = (Integer)((java_cup.runtime.Symbol) CUP$parser$stack.elementAt(CUP$parser$top-0)).value;
+		 RESULT = new Integer(e1.intValue() - e2.intValue()); 
+              CUP$parser$result = new java_cup.runtime.Symbol(3/*expr*/, ((java_cup.runtime.Symbol)CUP$parser$stack.elementAt(CUP$parser$top-2)).left, ((java_cup.runtime.Symbol)CUP$parser$stack.elementAt(CUP$parser$top-0)).right, RESULT);
+            }
+          return CUP$parser$result;
+
+          /*. . . . . . . . . . . . . . . . . . . .*/
+          case 5: // expr ::= expr PLUS expr 
+            {
+              Integer RESULT = null;
+		int e1left = ((java_cup.runtime.Symbol)CUP$parser$stack.elementAt(CUP$parser$top-2)).left;
+		int e1right = ((java_cup.runtime.Symbol)CUP$parser$stack.elementAt(CUP$parser$top-2)).right;
+		Integer e1 = (Integer)((java_cup.runtime.Symbol) CUP$parser$stack.elementAt(CUP$parser$top-2)).value;
+		int e2left = ((java_cup.runtime.Symbol)CUP$parser$stack.elementAt(CUP$parser$top-0)).left;
+		int e2right = ((java_cup.runtime.Symbol)CUP$parser$stack.elementAt(CUP$parser$top-0)).right;
+		Integer e2 = (Integer)((java_cup.runtime.Symbol) CUP$parser$stack.elementAt(CUP$parser$top-0)).value;
+		 RESULT = new Integer(e1.intValue() + e2.intValue()); 
+              CUP$parser$result = new java_cup.runtime.Symbol(3/*expr*/, ((java_cup.runtime.Symbol)CUP$parser$stack.elementAt(CUP$parser$top-2)).left, ((java_cup.runtime.Symbol)CUP$parser$stack.elementAt(CUP$parser$top-0)).right, RESULT);
+            }
+          return CUP$parser$result;
+
+          /*. . . . . . . . . . . . . . . . . . . .*/
+          case 4: // expr_part ::= expr NT$0 SEMI 
+            {
+              Object RESULT = null;
+              // propagate RESULT from NT$0
+              if ( ((java_cup.runtime.Symbol) CUP$parser$stack.elementAt(CUP$parser$top-1)).value != null )
+                RESULT = (Object) ((java_cup.runtime.Symbol) CUP$parser$stack.elementAt(CUP$parser$top-1)).value;
+		int eleft = ((java_cup.runtime.Symbol)CUP$parser$stack.elementAt(CUP$parser$top-2)).left;
+		int eright = ((java_cup.runtime.Symbol)CUP$parser$stack.elementAt(CUP$parser$top-2)).right;
+		Integer e = (Integer)((java_cup.runtime.Symbol) CUP$parser$stack.elementAt(CUP$parser$top-2)).value;
+
+              CUP$parser$result = new java_cup.runtime.Symbol(2/*expr_part*/, ((java_cup.runtime.Symbol)CUP$parser$stack.elementAt(CUP$parser$top-2)).left, ((java_cup.runtime.Symbol)CUP$parser$stack.elementAt(CUP$parser$top-0)).right, RESULT);
+            }
+          return CUP$parser$result;
+
+          /*. . . . . . . . . . . . . . . . . . . .*/
+          case 3: // NT$0 ::= 
+            {
+              Object RESULT = null;
+		int eleft = ((java_cup.runtime.Symbol)CUP$parser$stack.elementAt(CUP$parser$top-0)).left;
+		int eright = ((java_cup.runtime.Symbol)CUP$parser$stack.elementAt(CUP$parser$top-0)).right;
+		Integer e = (Integer)((java_cup.runtime.Symbol) CUP$parser$stack.elementAt(CUP$parser$top-0)).value;
+ System.out.println("= " + e); 
+              CUP$parser$result = new java_cup.runtime.Symbol(4/*NT$0*/, ((java_cup.runtime.Symbol)CUP$parser$stack.elementAt(CUP$parser$top-0)).right, ((java_cup.runtime.Symbol)CUP$parser$stack.elementAt(CUP$parser$top-0)).right, RESULT);
+            }
+          return CUP$parser$result;
+
+          /*. . . . . . . . . . . . . . . . . . . .*/
+          case 2: // expr_list ::= expr_part 
+            {
+              Object RESULT = null;
+
+              CUP$parser$result = new java_cup.runtime.Symbol(1/*expr_list*/, ((java_cup.runtime.Symbol)CUP$parser$stack.elementAt(CUP$parser$top-0)).left, ((java_cup.runtime.Symbol)CUP$parser$stack.elementAt(CUP$parser$top-0)).right, RESULT);
+            }
+          return CUP$parser$result;
+
+          /*. . . . . . . . . . . . . . . . . . . .*/
+          case 1: // $START ::= expr_list EOF 
+            {
+              Object RESULT = null;
+		int start_valleft = ((java_cup.runtime.Symbol)CUP$parser$stack.elementAt(CUP$parser$top-1)).left;
+		int start_valright = ((java_cup.runtime.Symbol)CUP$parser$stack.elementAt(CUP$parser$top-1)).right;
+		Object start_val = (Object)((java_cup.runtime.Symbol) CUP$parser$stack.elementAt(CUP$parser$top-1)).value;
+		RESULT = start_val;
+              CUP$parser$result = new java_cup.runtime.Symbol(0/*$START*/, ((java_cup.runtime.Symbol)CUP$parser$stack.elementAt(CUP$parser$top-1)).left, ((java_cup.runtime.Symbol)CUP$parser$stack.elementAt(CUP$parser$top-0)).right, RESULT);
+            }
+          /* ACCEPT */
+          CUP$parser$parser.done_parsing();
+          return CUP$parser$result;
+
+          /*. . . . . . . . . . . . . . . . . . . .*/
+          case 0: // expr_list ::= expr_list expr_part 
+            {
+              Object RESULT = null;
+
+              CUP$parser$result = new java_cup.runtime.Symbol(1/*expr_list*/, ((java_cup.runtime.Symbol)CUP$parser$stack.elementAt(CUP$parser$top-1)).left, ((java_cup.runtime.Symbol)CUP$parser$stack.elementAt(CUP$parser$top-0)).right, RESULT);
+            }
+          return CUP$parser$result;
+
+          /* . . . . . .*/
+          default:
+            throw new Exception(
+               "Invalid action number found in internal parse table");
+
+        }
+    }
+}
+
diff --git a/src/java_cup/simple_calc/scanner.java b/src/java_cup/simple_calc/scanner.java
new file mode 100644
index 0000000..f8f850a
--- /dev/null
+++ b/src/java_cup/simple_calc/scanner.java
@@ -0,0 +1,63 @@
+// Simple Example Scanner Class
+
+package java_cup.simple_calc;
+
+import java_cup.runtime.Symbol;
+
+public class scanner implements java_cup.runtime.Scanner {
+  final java.io.InputStream instream;
+
+  public scanner(java.io.InputStream is) throws java.io.IOException {
+    instream = is;
+  }
+  public scanner() throws java.io.IOException { this(System.in); }
+
+  /* single lookahead character */
+  protected int next_char = -2;
+
+  /* advance input by one character */
+  protected void advance()
+    throws java.io.IOException
+    { next_char = instream.read(); }
+
+  /* initialize the scanner */
+  private void init()
+    throws java.io.IOException
+    { advance(); }
+
+  /* recognize and return the next complete token */
+  public Symbol next_token()
+    throws java.io.IOException
+    {
+      if (next_char==-2) init(); // set stuff up first time we are called.
+      for (;;)
+        switch (next_char)
+	  {
+	    case '0': case '1': case '2': case '3': case '4': 
+	    case '5': case '6': case '7': case '8': case '9': 
+	      /* parse a decimal integer */
+	      int i_val = 0;
+	      do {
+	        i_val = i_val * 10 + (next_char - '0');
+	        advance();
+	      } while (next_char >= '0' && next_char <= '9');
+	    return new Symbol(sym.NUMBER, new Integer(i_val));
+
+	    case ';': advance(); return new Symbol(sym.SEMI);
+	    case '+': advance(); return new Symbol(sym.PLUS);
+	    case '-': advance(); return new Symbol(sym.MINUS);
+	    case '*': advance(); return new Symbol(sym.TIMES);
+	    case '/': advance(); return new Symbol(sym.DIVIDE);
+	    case '%': advance(); return new Symbol(sym.MOD);
+	    case '(': advance(); return new Symbol(sym.LPAREN);
+	    case ')': advance(); return new Symbol(sym.RPAREN);
+
+	    case -1: return new Symbol(sym.EOF);
+
+	    default: 
+	      /* in this simple scanner we just ignore everything else */
+	      advance();
+	    break;
+	  }
+    }
+};
diff --git a/src/java_cup/simple_calc/sym.java b/src/java_cup/simple_calc/sym.java
new file mode 100644
index 0000000..2584f2f
--- /dev/null
+++ b/src/java_cup/simple_calc/sym.java
@@ -0,0 +1,25 @@
+
+//----------------------------------------------------
+// The following code was generated by CUP v0.10k
+// Sun Jul 25 13:36:02 EDT 1999
+//----------------------------------------------------
+
+package java_cup.simple_calc;
+
+/** CUP generated class containing symbol constants. */
+public class sym {
+  /* terminals */
+  public static final int SEMI = 2;
+  public static final int EOF = 0;
+  public static final int DIVIDE = 6;
+  public static final int NUMBER = 11;
+  public static final int error = 1;
+  public static final int UMINUS = 8;
+  public static final int MINUS = 4;
+  public static final int TIMES = 5;
+  public static final int LPAREN = 9;
+  public static final int RPAREN = 10;
+  public static final int MOD = 7;
+  public static final int PLUS = 3;
+}
+