misc AST cleanups

virtdata-lang/src/main/java/io/nosqlbench/virtdata/lang/ast/Assignment.java

@@ -1,7 +1,8 @@
 package io.nosqlbench.virtdata.lang.ast;
 
 public class Assignment {
-    private String variableName;
+
+    private final String variableName;
 
     public Assignment(String variableName) {
         this.variableName = variableName;

virtdata-lang/src/main/java/io/nosqlbench/virtdata/lang/ast/BooleanArg.java

@@ -1,6 +1,7 @@
 package io.nosqlbench.virtdata.lang.ast;
 
 public class BooleanArg implements ArgType {
+
     private final boolean boolValue;
 
     public BooleanArg(boolean boolValue) {

virtdata-lang/src/main/java/io/nosqlbench/virtdata/lang/ast/FunctionCall.java

@@ -5,7 +5,7 @@ import java.util.List;
 
 public class FunctionCall implements ArgType {
     private String funcName;
-    private List<ArgType> args = new ArrayList<>();
+    private final List<ArgType> args = new ArrayList<>();
     private String inputType;
     private String outputType;
     private String inputClass;

virtdata-lang/src/main/java/io/nosqlbench/virtdata/lang/ast/IntegerArg.java

@@ -1,6 +1,7 @@
 package io.nosqlbench.virtdata.lang.ast;
 
 public class IntegerArg implements ArgType {
+
     private final int intValue;
 
     public IntegerArg(Integer integer) {

virtdata-lang/src/main/java/io/nosqlbench/virtdata/lang/ast/LongArg.java

@@ -1,6 +1,7 @@
 package io.nosqlbench.virtdata.lang.ast;
 
 public class LongArg implements ArgType {
+
     private final long longValue;
 
     public LongArg(Long longValue) {

virtdata-lang/src/main/java/io/nosqlbench/virtdata/lang/ast/RefArg.java

@@ -1,6 +1,7 @@
 package io.nosqlbench.virtdata.lang.ast;
 
 public class RefArg implements ArgType {
+
     private final String refName;
 
     public RefArg(String refName) {

virtdata-lang/src/main/java/io/nosqlbench/virtdata/lang/ast/StringArg.java

@@ -1,6 +1,7 @@
 package io.nosqlbench.virtdata.lang.ast;
 
 public class StringArg implements ArgType {
+
     private final String rawEscapedText;
     private final String unEscapedText;
 

virtdata-lang/src/main/java/io/nosqlbench/virtdata/lang/ast/VariableRef.java

@@ -1,9 +1,14 @@
 package io.nosqlbench.virtdata.lang.ast;
 
 public class VariableRef {
+
     private final String refName;
 
     public VariableRef(String refName) {
         this.refName = refName;
     }
+
+    public String getRefName() {
+        return this.refName;
+    }
 }

virtdata-lang/src/main/java/io/nosqlbench/virtdata/lang/ast/VirtDataAST.java

@@ -4,7 +4,8 @@ import java.util.ArrayList;
 import java.util.List;
 
 public class VirtDataAST {
-    private List<VirtDataFlow> flows = new ArrayList<>();
+
+    private final List<VirtDataFlow> flows = new ArrayList<>();
 
     public void addFlow(VirtDataFlow flow) {
         this.flows.add(flow);

virtdata-lang/src/main/java/io/nosqlbench/virtdata/lang/ast/VirtDataFlow.java

@@ -4,7 +4,8 @@ import java.util.ArrayList;
 import java.util.List;
 
 public class VirtDataFlow {
-    private List<Expression> expressions = new ArrayList<>();
+
+    private final List<Expression> expressions = new ArrayList<>();
 
     public List<Expression> getExpressions() {
         return expressions;