Make inputDataType final to ensure complete at construction time.

8 files changed, 54 insertions, 43 deletions

diff --git a/indexinglanguage/src/main/java/com/yahoo/vespa/indexinglanguage/expressions/ArithmeticExpression.java b/indexinglanguage/src/main/java/com/yahoo/vespa/indexinglanguage/expressions/ArithmeticExpression.java
index 02c68bdf967..68b9e79e092 100644
--- a/indexinglanguage/src/main/java/com/yahoo/vespa/indexinglanguage/expressions/ArithmeticExpression.java
+++ b/indexinglanguage/src/main/java/com/yahoo/vespa/indexinglanguage/expressions/ArithmeticExpression.java
@@ -46,8 +46,7 @@ public final class ArithmeticExpression extends CompositeExpression {
     private final Expression rhs;
 
     public ArithmeticExpression(Expression lhs, Operator op, Expression rhs) {
-        super(null);
-        setInputType(requiredInputType(lhs, rhs));
+        super(requiredInputType(lhs, rhs));
         lhs.getClass(); // throws NullPointerException
         op.getClass();
         rhs.getClass();
@@ -82,7 +81,7 @@ public final class ArithmeticExpression extends CompositeExpression {
                                   context.setValue(input).execute(rhs).getValue()));
     }
 
-    private DataType requiredInputType(Expression lhs, Expression rhs) {
+    private static DataType requiredInputType(Expression lhs, Expression rhs) {
         DataType lhsType = lhs.requiredInputType();
         DataType rhsType = rhs.requiredInputType();
         if (lhsType == null) {
@@ -92,7 +91,7 @@ public final class ArithmeticExpression extends CompositeExpression {
             return lhsType;
         }
         if (!lhsType.equals(rhsType)) {
-            throw new VerificationException(this, "Operands require conflicting input types, " +
+            throw new VerificationException(ArithmeticExpression.class, "Operands require conflicting input types, " +
                                                   lhsType.getName() + " vs " + rhsType.getName() + ".");
         }
         return lhsType;
diff --git a/indexinglanguage/src/main/java/com/yahoo/vespa/indexinglanguage/expressions/CatExpression.java b/indexinglanguage/src/main/java/com/yahoo/vespa/indexinglanguage/expressions/CatExpression.java
index be6b6db6a9a..f395446cb10 100644
--- a/indexinglanguage/src/main/java/com/yahoo/vespa/indexinglanguage/expressions/CatExpression.java
+++ b/indexinglanguage/src/main/java/com/yahoo/vespa/indexinglanguage/expressions/CatExpression.java
@@ -18,12 +18,11 @@ import java.util.*;
 public final class CatExpression extends ExpressionList<Expression> {
 
     public CatExpression(Expression... lst) {
-        super(Arrays.asList(lst));
-        setInputType(resolveInputType());
+        this(Arrays.asList(lst));
     }
 
     public CatExpression(Collection<? extends Expression> lst) {
-        super(lst);
+        super(lst, resolveInputType(lst));
     }
 
     @Override
@@ -63,17 +62,17 @@ public final class CatExpression extends ExpressionList<Expression> {
         context.setValue(resolveOutputType(types));
     }
 
-    private DataType resolveInputType() {
+    private static DataType resolveInputType(Collection<? extends Expression> list) {
         DataType prev = null;
-        for (Expression exp : this) {
+        for (Expression exp : list) {
             DataType next = exp.requiredInputType();
             if (next == null) {
                 // ignore
             } else if (prev == null) {
                 prev = next;
             } else if (!prev.isAssignableFrom(next)) {
-                throw new VerificationException(this, "Operands require conflicting input types, " +
-                                                      prev.getName() + " vs " + next.getName() + ".");
+                throw new VerificationException(CatExpression.class, "Operands require conflicting input types, " +
+                                                                      prev.getName() + " vs " + next.getName() + ".");
             }
         }
         return prev;
diff --git a/indexinglanguage/src/main/java/com/yahoo/vespa/indexinglanguage/expressions/Expression.java b/indexinglanguage/src/main/java/com/yahoo/vespa/indexinglanguage/expressions/Expression.java
index 3d8da1a8b77..231446b9c62 100644
--- a/indexinglanguage/src/main/java/com/yahoo/vespa/indexinglanguage/expressions/Expression.java
+++ b/indexinglanguage/src/main/java/com/yahoo/vespa/indexinglanguage/expressions/Expression.java
@@ -17,14 +17,12 @@ import com.yahoo.vespa.objects.Selectable;
  */
 public abstract class Expression extends Selectable {
 
-    private DataType inputType;
+    private final DataType inputType;
 
     protected Expression(DataType inputType) {
         this.inputType = inputType;
     }
-    protected void setInputType(DataType inputType) {
-        this.inputType = inputType;
-    }
+
     public final FieldValue execute(FieldValue val) {
         return execute(new ExecutionContext().setValue(val));
     }
diff --git a/indexinglanguage/src/main/java/com/yahoo/vespa/indexinglanguage/expressions/ExpressionList.java b/indexinglanguage/src/main/java/com/yahoo/vespa/indexinglanguage/expressions/ExpressionList.java
index 6c83835559c..ca929773a4c 100644
--- a/indexinglanguage/src/main/java/com/yahoo/vespa/indexinglanguage/expressions/ExpressionList.java
+++ b/indexinglanguage/src/main/java/com/yahoo/vespa/indexinglanguage/expressions/ExpressionList.java
@@ -1,6 +1,7 @@
 // Copyright 2017 Yahoo Holdings. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
 package com.yahoo.vespa.indexinglanguage.expressions;
 
+import com.yahoo.document.DataType;
 import com.yahoo.document.DocumentType;
 import com.yahoo.vespa.objects.ObjectOperation;
 import com.yahoo.vespa.objects.ObjectPredicate;
@@ -17,12 +18,8 @@ public abstract class ExpressionList<T extends Expression> extends CompositeExpr
 
     private final List<T> expressions = new LinkedList<T>();
 
-    protected ExpressionList() {
-        super(null);
-    }
-
-    protected ExpressionList(Iterable<? extends T> lst) {
-        super(null);
+    protected ExpressionList(Iterable<? extends T> lst, DataType inputType) {
+        super(inputType);
         for (T exp : lst) {
             this.expressions.add(exp);
         }
diff --git a/indexinglanguage/src/main/java/com/yahoo/vespa/indexinglanguage/expressions/IfThenExpression.java b/indexinglanguage/src/main/java/com/yahoo/vespa/indexinglanguage/expressions/IfThenExpression.java
index 16365e1264b..9e7f60aa3e3 100644
--- a/indexinglanguage/src/main/java/com/yahoo/vespa/indexinglanguage/expressions/IfThenExpression.java
+++ b/indexinglanguage/src/main/java/com/yahoo/vespa/indexinglanguage/expressions/IfThenExpression.java
@@ -46,13 +46,12 @@ public final class IfThenExpression extends CompositeExpression {
     }
 
     public IfThenExpression(Expression lhs, Comparator cmp, Expression rhs, Expression ifTrue, Expression ifFalse) {
-        super(null);
+        super(resolveInputType(lhs, rhs, ifTrue, ifFalse));
         this.lhs = lhs;
         this.cmp = cmp;
         this.rhs = rhs;
         this.ifTrue = ifTrue;
         this.ifFalse = ifFalse;
-        setInputType(resolveInputType());
     }
 
     public Expression getLeftHandSide() {
@@ -114,7 +113,7 @@ public final class IfThenExpression extends CompositeExpression {
         select(ifFalse, predicate, operation);
     }
 
-    private DataType resolveInputType() {
+    private static DataType resolveInputType(Expression lhs, Expression rhs, Expression ifTrue, Expression ifFalse) {
         DataType input = null;
         input = resolveRequiredInputType(input, lhs.requiredInputType());
         input = resolveRequiredInputType(input, rhs.requiredInputType());
@@ -174,7 +173,7 @@ public final class IfThenExpression extends CompositeExpression {
         return ret;
     }
 
-    private DataType resolveRequiredInputType(DataType prev, DataType next) {
+    private static DataType resolveRequiredInputType(DataType prev, DataType next) {
         if (next == null) {
             return prev;
         }
@@ -182,7 +181,7 @@ public final class IfThenExpression extends CompositeExpression {
             return next;
         }
         if (!prev.equals(next)) {
-            throw new VerificationException(this, "Operands require conflicting input types, " +
+            throw new VerificationException(IfThenExpression.class, "Operands require conflicting input types, " +
                                                   prev.getName() + " vs " + next.getName() + ".");
         }
         return prev;
diff --git a/indexinglanguage/src/main/java/com/yahoo/vespa/indexinglanguage/expressions/ScriptExpression.java b/indexinglanguage/src/main/java/com/yahoo/vespa/indexinglanguage/expressions/ScriptExpression.java
index 275ca58d4db..3e9f6ad5032 100644
--- a/indexinglanguage/src/main/java/com/yahoo/vespa/indexinglanguage/expressions/ScriptExpression.java
+++ b/indexinglanguage/src/main/java/com/yahoo/vespa/indexinglanguage/expressions/ScriptExpression.java
@@ -12,6 +12,7 @@ import com.yahoo.vespa.indexinglanguage.parser.ParseException;
 
 import java.util.Arrays;
 import java.util.Collection;
+import java.util.Collections;
 import java.util.Iterator;
 
 /**
@@ -20,18 +21,15 @@ import java.util.Iterator;
 public final class ScriptExpression extends ExpressionList<StatementExpression> {
 
     public ScriptExpression() {
-        super();
-        setInputType(resolveInputType());
+        this(Collections.emptyList());
     }
 
     public ScriptExpression(StatementExpression... lst) {
-        super(Arrays.asList(lst));
-        setInputType(resolveInputType());
+        this(Arrays.asList(lst));
     }
 
     public ScriptExpression(Collection<? extends StatementExpression> lst) {
-        super(lst);
-        setInputType(resolveInputType());
+        super(lst, resolveInputType(lst));
     }
 
     @Override
@@ -52,14 +50,14 @@ public final class ScriptExpression extends ExpressionList<StatementExpression>
         context.setValue(input);
     }
 
-    private DataType resolveInputType() {
+    private static DataType resolveInputType(Collection<? extends StatementExpression> list) {
         DataType prev = null;
-        for (Expression exp : this) {
+        for (Expression exp : list) {
             DataType next = exp.requiredInputType();
             if (prev == null) {
                 prev = next;
             } else if (next != null && !prev.isAssignableFrom(next)) {
-                throw new VerificationException(this, "Statements require conflicting input types, " +
+                throw new VerificationException(ScriptExpression.class, "Statements require conflicting input types, " +
                                                       prev.getName() + " vs " + next.getName() + ".");
             }
         }
diff --git a/indexinglanguage/src/main/java/com/yahoo/vespa/indexinglanguage/expressions/StatementExpression.java b/indexinglanguage/src/main/java/com/yahoo/vespa/indexinglanguage/expressions/StatementExpression.java
index eb6b5563584..422457d18fa 100644
--- a/indexinglanguage/src/main/java/com/yahoo/vespa/indexinglanguage/expressions/StatementExpression.java
+++ b/indexinglanguage/src/main/java/com/yahoo/vespa/indexinglanguage/expressions/StatementExpression.java
@@ -10,6 +10,7 @@ import com.yahoo.vespa.indexinglanguage.parser.IndexingInput;
 import com.yahoo.vespa.indexinglanguage.parser.ParseException;
 
 import java.util.Arrays;
+import java.util.Collection;
 import java.util.Iterator;
 import java.util.LinkedList;
 import java.util.List;
@@ -21,12 +22,14 @@ public final class StatementExpression extends ExpressionList<Expression> {
 
     public StatementExpression(Expression... lst) {
         this(Arrays.asList(lst));
-        setInputType(resolveInputType());
     }
 
     public StatementExpression(Iterable<Expression> lst) {
-        super(filterList(lst));
-        setInputType(resolveInputType());
+        this(filterList(lst), null);
+    }
+
+    private StatementExpression(Iterable<Expression> list, Object unused) {
+        super(list, resolveInputType(list));
     }
 
     @Override
@@ -43,12 +46,13 @@ public final class StatementExpression extends ExpressionList<Expression> {
         }
     }
 
-    private DataType resolveInputType() {
-        for (Expression exp : this) {
+    private static DataType resolveInputType(Iterable<Expression> lst) {
+        for (Expression exp : lst) {
             DataType type = exp.requiredInputType();
             if (type != null) {
                 return type;
             }
+
             type = exp.createdOutputType();
             if (type != null) {
                 return null;
diff --git a/indexinglanguage/src/main/java/com/yahoo/vespa/indexinglanguage/expressions/VerificationException.java b/indexinglanguage/src/main/java/com/yahoo/vespa/indexinglanguage/expressions/VerificationException.java
index 32f337f500c..836600caa2b 100644
--- a/indexinglanguage/src/main/java/com/yahoo/vespa/indexinglanguage/expressions/VerificationException.java
+++ b/indexinglanguage/src/main/java/com/yahoo/vespa/indexinglanguage/expressions/VerificationException.java
@@ -6,16 +6,33 @@ package com.yahoo.vespa.indexinglanguage.expressions;
  */
 public class VerificationException extends RuntimeException {
 
-    private final Expression exp;
+    private final Class<?> type;
+    private final String exp;
 
     public VerificationException(Expression exp, String msg) {
         super(msg);
-        this.exp = exp;
+        if (exp != null) {
+            this.type = exp.getClass();
+            this.exp = exp.toString();
+        } else {
+            this.type = null;
+            this.exp = "null";
+        }
     }
 
-    public Expression getExpression() {
+
+    public VerificationException(Class<?> exp, String msg) {
+        super(msg);
+        this.type = exp;
+        this.exp = exp.getName();
+    }
+
+    public String getExpression() {
         return exp;
     }
+    public Class<?> getExpressionType() {
+        return type;
+    }
 
     @Override
     public String toString() {