Modulo operation was implemented (as it was described in #44 issue)

src/main/scala/org/arnoldc/ArnoldParser.scala

@@ -39,6 +39,7 @@ class ArnoldParser extends Parser {
   val CallMethod = "DO IT NOW"
   val NonVoidMethod = "GIVE THESE PEOPLE AIR"
   val AssignVariableFromMethodCall = "GET YOUR ASS TO MARS"
+  val Modulo = "I LET HIM GO"
 
   val EOL = zeroOrMore("\t" | "\r" | " ") ~ "\n" ~ zeroOrMore("\t" | "\r" | " " | "\n")
   val WhiteSpace = oneOrMore(" " | "\t")
@@ -136,7 +137,8 @@ class ArnoldParser extends Parser {
     PlusExpression ~~> PlusExpressionNode |
       MinusExpression ~~> MinusExpressionNode |
       MultiplicationExpression ~~> MultiplicationExpressionNode |
-      DivisionExpression ~~> DivisionExpressionNode
+      DivisionExpression ~~> DivisionExpressionNode |
+      ModuloExpression ~~> ModuloExpressionNode
   }
 
   def SetValueExpression: Rule1[OperandNode] = rule {
@@ -160,6 +162,10 @@ class ArnoldParser extends Parser {
     DivisionOperator ~ WhiteSpace ~ Operand ~ EOL
   }
 
+  def ModuloExpression: Rule1[AstNode] = rule {
+    Modulo ~ WhiteSpace ~ Operand ~ EOL
+  }
+
   def Variable: Rule1[VariableNode] = rule {
     VariableName ~> VariableNode
   }

src/main/scala/org/arnoldc/ast/ModuloExpressionNode.scala

@@ -0,0 +1,14 @@
+package org.arnoldc.ast
+
+import org.objectweb.asm.MethodVisitor
+import org.objectweb.asm.Opcodes._
+import org.arnoldc.SymbolTable
+
+
+case class ModuloExpressionNode(expression: AstNode ,operand: AstNode ) extends AstNode {
+  def generate(mv: MethodVisitor, symbolTable: SymbolTable) {
+    expression.generate(mv, symbolTable)
+    operand.generate(mv, symbolTable)
+    mv.visitInsn(IREM)
+  }
+}

src/test/scala/org/arnoldc/ArithmeticTest.scala

@@ -291,6 +291,34 @@ class ArithmeticTest extends ArnoldGeneratorTest {
     getOutput(code) should equal("2\n")
   }
 
+  it should "evaluate when calculating modulo variables vol1" in {
+    val code =
+      "IT'S SHOWTIME\n" +
+        "HEY CHRISTMAS TREE var\n" +
+        "YOU SET US UP 1\n" +
+        "GET TO THE CHOPPER var\n" +
+        "HERE IS MY INVITATION var\n" +
+        "I LET HIM GO 2\n" +
+        "ENOUGH TALK\n" +
+        "TALK TO THE HAND var\n" +
+        "YOU HAVE BEEN TERMINATED\n"
+    getOutput(code) should equal("1\n")
+  }
+
+  it should "evaluate when calculating modulo variables vol2" in {
+    val code =
+      "IT'S SHOWTIME\n" +
+        "HEY CHRISTMAS TREE var\n" +
+        "YOU SET US UP 2\n" +
+        "GET TO THE CHOPPER var\n" +
+        "HERE IS MY INVITATION var\n" +
+        "I LET HIM GO 2\n" +
+        "ENOUGH TALK\n" +
+        "TALK TO THE HAND var\n" +
+        "YOU HAVE BEEN TERMINATED\n"
+    getOutput(code) should equal("0\n")
+  }
+
   it should "evaluate using different arithmetic operations" in {
     val code =
       "IT'S SHOWTIME\n" +