Revert "Revert "Bratseth/typecheck all 3""

16 files changed, 195 insertions, 48 deletions

diff --git a/vespajlib/src/main/java/com/yahoo/lang/MutableLong.java b/vespajlib/src/main/java/com/yahoo/lang/MutableLong.java
new file mode 100644
index 00000000000..e0e4a0828a9
--- /dev/null
+++ b/vespajlib/src/main/java/com/yahoo/lang/MutableLong.java
@@ -0,0 +1,33 @@
+// Copyright 2018 Yahoo Holdings. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
+package com.yahoo.lang;
+
+/**
+ * A mutable long
+ *
+ * @author bratseth
+ */
+public class MutableLong {
+
+    private long value;
+
+    public MutableLong(long value) {
+        this.value = value;
+    }
+
+    public long get() { return value; }
+
+    public void set(long value) { this.value = value; }
+
+    /** Adds the increment to the current value and returns the resulting value */
+    public long add(long increment) {
+        value += increment;
+        return value;
+    }
+
+    /** Adds the increment to the current value and returns the resulting value */
+    public long subtract(long increment) {
+        value -= increment;
+        return value;
+    }
+
+}
diff --git a/vespajlib/src/main/java/com/yahoo/tensor/TensorType.java b/vespajlib/src/main/java/com/yahoo/tensor/TensorType.java
index 14cd3e70866..bf1825446e4 100644
--- a/vespajlib/src/main/java/com/yahoo/tensor/TensorType.java
+++ b/vespajlib/src/main/java/com/yahoo/tensor/TensorType.java
@@ -77,6 +77,13 @@ public class TensorType {
         return Optional.empty();
     }
 
+    /* Returns the bound of this dimension if it is present and bound in this, empty otherwise */
+    public Optional<Long> sizeOfDimension(String dimension) {
+        Optional<Dimension> d = dimension(dimension);
+        if ( ! d.isPresent()) return Optional.empty();
+        return d.get().size();
+    }
+
     /**
      * Returns whether this type can be assigned to the given type,
      * i.e if the given type is a generalization of this type.
diff --git a/vespajlib/src/main/java/com/yahoo/tensor/evaluation/EvaluationContext.java b/vespajlib/src/main/java/com/yahoo/tensor/evaluation/EvaluationContext.java
index 3fb94f1251b..8a969180113 100644
--- a/vespajlib/src/main/java/com/yahoo/tensor/evaluation/EvaluationContext.java
+++ b/vespajlib/src/main/java/com/yahoo/tensor/evaluation/EvaluationContext.java
@@ -10,7 +10,7 @@ import com.yahoo.tensor.Tensor;
  * @author bratseth
  */
 @Beta
-public interface EvaluationContext extends TypeContext {
+public interface EvaluationContext<NAMETYPE extends TypeContext.Name> extends TypeContext<NAMETYPE> {
 
     /** Returns the tensor bound to this name, or null if none */
     Tensor getTensor(String name);
diff --git a/vespajlib/src/main/java/com/yahoo/tensor/evaluation/MapEvaluationContext.java b/vespajlib/src/main/java/com/yahoo/tensor/evaluation/MapEvaluationContext.java
index 9fe6b7d053f..b9394da31e3 100644
--- a/vespajlib/src/main/java/com/yahoo/tensor/evaluation/MapEvaluationContext.java
+++ b/vespajlib/src/main/java/com/yahoo/tensor/evaluation/MapEvaluationContext.java
@@ -11,17 +11,20 @@ import java.util.HashMap;
  * @author bratseth
  */
 @Beta
-public class MapEvaluationContext implements EvaluationContext {
+public class MapEvaluationContext implements EvaluationContext<TypeContext.Name> {
 
     private final java.util.Map<String, Tensor> bindings = new HashMap<>();
 
-    static MapEvaluationContext empty() { return new MapEvaluationContext(); }
-
     public void put(String name, Tensor tensor) { bindings.put(name, tensor); }
 
     @Override
     public TensorType getType(String name) {
-        Tensor tensor = bindings.get(name);
+        return getType(new Name(name));
+    }
+
+    @Override
+    public TensorType getType(Name name) {
+        Tensor tensor = bindings.get(name.toString());
         if (tensor == null) return null;
         return tensor.type();
     }
diff --git a/vespajlib/src/main/java/com/yahoo/tensor/evaluation/TypeContext.java b/vespajlib/src/main/java/com/yahoo/tensor/evaluation/TypeContext.java
index 760a225efdf..ff2e6318b37 100644
--- a/vespajlib/src/main/java/com/yahoo/tensor/evaluation/TypeContext.java
+++ b/vespajlib/src/main/java/com/yahoo/tensor/evaluation/TypeContext.java
@@ -8,7 +8,7 @@ import com.yahoo.tensor.TensorType;
  *
  * @author bratseth
  */
-public interface TypeContext {
+public interface TypeContext<NAMETYPE extends TypeContext.Name> {
 
     /**
      * Returns the type of the tensor with this name.
@@ -16,6 +16,39 @@ public interface TypeContext {
      * @return returns the type of the tensor which will be returned by calling getTensor(name)
      *         or null if getTensor will return null.
      */
+    TensorType getType(NAMETYPE name);
+
+    /**
+     * Returns the type of the tensor with this name by converting from a string name.
+     *
+     * @return returns the type of the tensor which will be returned by calling getTensor(name)
+     *         or null if getTensor will return null.
+     */
     TensorType getType(String name);
 
+    /** A name which is just a string. Names are value objects. */
+    class Name {
+
+        private final String name;
+
+        public Name(String name) {
+            this.name = name;
+        }
+
+        @Override
+        public String toString() { return name; }
+
+        @Override
+        public int hashCode() { return name.hashCode(); }
+
+        @Override
+        public boolean equals(Object other) {
+            if (other == this) return true;
+            if ( ! (other instanceof Name)) return false;
+            return ((Name)other).name.equals(this.name);
+        }
+
+    }
+
+
 }
diff --git a/vespajlib/src/main/java/com/yahoo/tensor/evaluation/VariableTensor.java b/vespajlib/src/main/java/com/yahoo/tensor/evaluation/VariableTensor.java
index 34beb465d4c..acb2363cba4 100644
--- a/vespajlib/src/main/java/com/yahoo/tensor/evaluation/VariableTensor.java
+++ b/vespajlib/src/main/java/com/yahoo/tensor/evaluation/VariableTensor.java
@@ -44,7 +44,7 @@ public class VariableTensor extends PrimitiveTensorFunction {
     public PrimitiveTensorFunction toPrimitive() { return this; }
 
     @Override
-    public TensorType type(TypeContext context) {
+    public <NAMETYPE extends TypeContext.Name> TensorType type(TypeContext<NAMETYPE> context) {
         TensorType givenType = context.getType(name);
         if (givenType == null) return null;
         verifyType(givenType);
@@ -52,7 +52,7 @@ public class VariableTensor extends PrimitiveTensorFunction {
     }
 
     @Override
-    public Tensor evaluate(EvaluationContext context) {
+    public <NAMETYPE extends TypeContext.Name> Tensor evaluate(EvaluationContext<NAMETYPE> context) {
         Tensor tensor = context.getTensor(name);
         if (tensor == null) return null;
         verifyType(tensor.type());
diff --git a/vespajlib/src/main/java/com/yahoo/tensor/functions/CompositeTensorFunction.java b/vespajlib/src/main/java/com/yahoo/tensor/functions/CompositeTensorFunction.java
index 2109b730e1a..bfc0938abcc 100644
--- a/vespajlib/src/main/java/com/yahoo/tensor/functions/CompositeTensorFunction.java
+++ b/vespajlib/src/main/java/com/yahoo/tensor/functions/CompositeTensorFunction.java
@@ -18,10 +18,14 @@ public abstract class CompositeTensorFunction extends TensorFunction {
 
     /** Finds the type this produces by first converting it to a primitive function */
     @Override
-    public final TensorType type(TypeContext context) { return toPrimitive().type(context); }
+    public final <NAMETYPE extends TypeContext.Name> TensorType type(TypeContext<NAMETYPE> context) {
+        return toPrimitive().type(context);
+    }
 
     /** Evaluates this by first converting it to a primitive function */
     @Override
-    public final Tensor evaluate(EvaluationContext context) { return toPrimitive().evaluate(context); }
+    public final <NAMETYPE extends TypeContext.Name> Tensor evaluate(EvaluationContext<NAMETYPE> context) {
+        return toPrimitive().evaluate(context);
+    }
 
 }
diff --git a/vespajlib/src/main/java/com/yahoo/tensor/functions/Concat.java b/vespajlib/src/main/java/com/yahoo/tensor/functions/Concat.java
index c77ed1c0526..13e7c136feb 100644
--- a/vespajlib/src/main/java/com/yahoo/tensor/functions/Concat.java
+++ b/vespajlib/src/main/java/com/yahoo/tensor/functions/Concat.java
@@ -3,6 +3,8 @@ package com.yahoo.tensor.functions;
 
 import com.google.common.annotations.Beta;
 import com.google.common.collect.ImmutableList;
+import com.yahoo.lang.MutableInteger;
+import com.yahoo.lang.MutableLong;
 import com.yahoo.tensor.DimensionSizes;
 import com.yahoo.tensor.IndexedTensor;
 import com.yahoo.tensor.Tensor;
@@ -60,21 +62,35 @@ public class Concat extends PrimitiveTensorFunction {
     }
 
     @Override
-    public TensorType type(TypeContext context) {
+    public <NAMETYPE extends TypeContext.Name> TensorType type(TypeContext<NAMETYPE> context) {
         return type(argumentA.type(context), argumentB.type(context));
     }
 
     /** Returns the type resulting from concatenating a and b */
     private TensorType type(TensorType a, TensorType b) {
+        // TODO: Fail if concat dimension is present but not indexed in a or b
         TensorType.Builder builder = new TensorType.Builder(a, b);
-        if (builder.getDimension(dimension).get().size().isPresent()) // both types have size: correct to concat size
-            builder.set(TensorType.Dimension.indexed(dimension, a.dimension(dimension).get().size().get() +
-                                                                b.dimension(dimension).get().size().get()));
+        if ( ! unboundIn(a, dimension) && ! unboundIn(b, dimension)) {
+            builder.set(TensorType.Dimension.indexed(dimension, a.sizeOfDimension(dimension).orElse(1L) +
+                                                                b.sizeOfDimension(dimension).orElse(1L)));
+            /*
+            MutableLong concatSize = new MutableLong(0);
+            a.sizeOfDimension(dimension).ifPresent(concatSize::add);
+            b.sizeOfDimension(dimension).ifPresent(concatSize::add);
+                builder.set(TensorType.Dimension.indexed(dimension, concatSize.get()));
+                */
+        }
         return builder.build();
     }
 
+    /** Returns true if this dimension is present and unbound */
+    private boolean unboundIn(TensorType type, String dimensionName) {
+        Optional<TensorType.Dimension> dimension = type.dimension(dimensionName);
+        return dimension.isPresent() && ! dimension.get().size().isPresent();
+    }
+
     @Override
-    public Tensor evaluate(EvaluationContext context) {
+    public <NAMETYPE extends TypeContext.Name> Tensor evaluate(EvaluationContext<NAMETYPE> context) {
         Tensor a = argumentA.evaluate(context);
         Tensor b = argumentB.evaluate(context);
         a = ensureIndexedDimension(dimension, a);
diff --git a/vespajlib/src/main/java/com/yahoo/tensor/functions/ConstantTensor.java b/vespajlib/src/main/java/com/yahoo/tensor/functions/ConstantTensor.java
index 50b479da168..a43de297b9a 100644
--- a/vespajlib/src/main/java/com/yahoo/tensor/functions/ConstantTensor.java
+++ b/vespajlib/src/main/java/com/yahoo/tensor/functions/ConstantTensor.java
@@ -42,10 +42,10 @@ public class ConstantTensor extends PrimitiveTensorFunction {
     public PrimitiveTensorFunction toPrimitive() { return this; }
 
     @Override
-    public TensorType type(TypeContext context) { return constant.type(); }
+    public <NAMETYPE extends TypeContext.Name> TensorType type(TypeContext<NAMETYPE> context) { return constant.type(); }
 
     @Override
-    public Tensor evaluate(EvaluationContext context) { return constant; }
+    public <NAMETYPE extends TypeContext.Name> Tensor evaluate(EvaluationContext<NAMETYPE> context) { return constant; }
 
     @Override
     public String toString(ToStringContext context) { return constant.toString(); }
diff --git a/vespajlib/src/main/java/com/yahoo/tensor/functions/Generate.java b/vespajlib/src/main/java/com/yahoo/tensor/functions/Generate.java
index e70d1de3db7..edfa8253eb9 100644
--- a/vespajlib/src/main/java/com/yahoo/tensor/functions/Generate.java
+++ b/vespajlib/src/main/java/com/yahoo/tensor/functions/Generate.java
@@ -61,10 +61,10 @@ public class Generate extends PrimitiveTensorFunction {
     public PrimitiveTensorFunction toPrimitive() { return this; }
 
     @Override
-    public TensorType type(TypeContext context) { return type; }
+    public <NAMETYPE extends TypeContext.Name> TensorType type(TypeContext<NAMETYPE> context) { return type; }
 
     @Override
-    public Tensor evaluate(EvaluationContext context) {
+    public <NAMETYPE extends TypeContext.Name> Tensor evaluate(EvaluationContext<NAMETYPE> context) {
         Tensor.Builder builder = Tensor.Builder.of(type);
         IndexedTensor.Indexes indexes = IndexedTensor.Indexes.of(dimensionSizes(type));
         for (int i = 0; i < indexes.size(); i++) {
diff --git a/vespajlib/src/main/java/com/yahoo/tensor/functions/Join.java b/vespajlib/src/main/java/com/yahoo/tensor/functions/Join.java
index 7812c985091..17e1c103ea3 100644
--- a/vespajlib/src/main/java/com/yahoo/tensor/functions/Join.java
+++ b/vespajlib/src/main/java/com/yahoo/tensor/functions/Join.java
@@ -95,12 +95,12 @@ public class Join extends PrimitiveTensorFunction {
     }
 
     @Override
-    public TensorType type(TypeContext context) {
+    public <NAMETYPE extends TypeContext.Name> TensorType type(TypeContext<NAMETYPE> context) {
         return new TensorType.Builder(argumentA.type(context), argumentB.type(context)).build();
     }
 
     @Override
-    public Tensor evaluate(EvaluationContext context) {
+    public <NAMETYPE extends TypeContext.Name> Tensor evaluate(EvaluationContext<NAMETYPE> context) {
         Tensor a = argumentA.evaluate(context);
         Tensor b = argumentB.evaluate(context);
         TensorType joinedType = new TensorType.Builder(a.type(), b.type()).build();
diff --git a/vespajlib/src/main/java/com/yahoo/tensor/functions/Map.java b/vespajlib/src/main/java/com/yahoo/tensor/functions/Map.java
index 53504868ff2..4a338e5501e 100644
--- a/vespajlib/src/main/java/com/yahoo/tensor/functions/Map.java
+++ b/vespajlib/src/main/java/com/yahoo/tensor/functions/Map.java
@@ -53,12 +53,12 @@ public class Map extends PrimitiveTensorFunction {
     }
 
     @Override
-    public TensorType type(TypeContext context) {
+    public <NAMETYPE extends TypeContext.Name> TensorType type(TypeContext<NAMETYPE> context) {
         return argument.type(context);
     }
 
     @Override
-    public Tensor evaluate(EvaluationContext context) {
+    public <NAMETYPE extends TypeContext.Name> Tensor evaluate(EvaluationContext<NAMETYPE> context) {
         Tensor argument = argument().evaluate(context);
         Tensor.Builder builder = Tensor.Builder.of(argument.type());
         for (Iterator<Tensor.Cell> i = argument.cellIterator(); i.hasNext(); ) {
diff --git a/vespajlib/src/main/java/com/yahoo/tensor/functions/Reduce.java b/vespajlib/src/main/java/com/yahoo/tensor/functions/Reduce.java
index 76a938b9fe2..e045effbe7e 100644
--- a/vespajlib/src/main/java/com/yahoo/tensor/functions/Reduce.java
+++ b/vespajlib/src/main/java/com/yahoo/tensor/functions/Reduce.java
@@ -101,11 +101,12 @@ public class Reduce extends PrimitiveTensorFunction {
     }
 
     @Override
-    public TensorType type(TypeContext context) {
+    public <NAMETYPE extends TypeContext.Name> TensorType type(TypeContext<NAMETYPE> context) {
         return type(argument.type(context));
     }
 
     private TensorType type(TensorType argumentType) {
+        if (dimensions.isEmpty()) return TensorType.empty; // means reduce all
         TensorType.Builder builder = new TensorType.Builder();
         for (TensorType.Dimension dimension : argumentType.dimensions())
             if ( ! dimensions.contains(dimension.name())) // keep
@@ -114,7 +115,7 @@ public class Reduce extends PrimitiveTensorFunction {
     }
 
     @Override
-    public Tensor evaluate(EvaluationContext context) {
+    public <NAMETYPE extends TypeContext.Name> Tensor evaluate(EvaluationContext<NAMETYPE> context) {
         Tensor argument = this.argument.evaluate(context);
         if ( ! dimensions.isEmpty() && ! argument.type().dimensionNames().containsAll(dimensions))
             throw new IllegalArgumentException("Cannot reduce " + argument + " over dimensions " +
diff --git a/vespajlib/src/main/java/com/yahoo/tensor/functions/Rename.java b/vespajlib/src/main/java/com/yahoo/tensor/functions/Rename.java
index de3d2be265a..af4492ca1e4 100644
--- a/vespajlib/src/main/java/com/yahoo/tensor/functions/Rename.java
+++ b/vespajlib/src/main/java/com/yahoo/tensor/functions/Rename.java
@@ -72,7 +72,7 @@ public class Rename extends PrimitiveTensorFunction {
     public PrimitiveTensorFunction toPrimitive() { return this; }
 
     @Override
-    public TensorType type(TypeContext context) {
+    public <NAMETYPE extends TypeContext.Name> TensorType type(TypeContext<NAMETYPE> context) {
         return type(argument.type(context));
     }
 
@@ -84,7 +84,7 @@ public class Rename extends PrimitiveTensorFunction {
     }
 
     @Override
-    public Tensor evaluate(EvaluationContext context) {
+    public <NAMETYPE extends TypeContext.Name> Tensor evaluate(EvaluationContext<NAMETYPE> context) {
         Tensor tensor = argument.evaluate(context);
 
         TensorType renamedType = type(tensor.type());
diff --git a/vespajlib/src/main/java/com/yahoo/tensor/functions/TensorFunction.java b/vespajlib/src/main/java/com/yahoo/tensor/functions/TensorFunction.java
index 78ab09c7820..e805e9d87bb 100644
--- a/vespajlib/src/main/java/com/yahoo/tensor/functions/TensorFunction.java
+++ b/vespajlib/src/main/java/com/yahoo/tensor/functions/TensorFunction.java
@@ -43,14 +43,14 @@ public abstract class TensorFunction {
      *
      * @param context a context which must be passed to all nexted functions when evaluating
      */
-    public abstract Tensor evaluate(EvaluationContext context);
+    public abstract <NAMETYPE extends TypeContext.Name> Tensor evaluate(EvaluationContext<NAMETYPE>  context);
 
     /**
      * Returns the type of the tensor this produces given the input types in the context
      *
      * @param context a context which must be passed to all nexted functions when evaluating
      */
-    public abstract TensorType type(TypeContext context);
+    public abstract <NAMETYPE extends TypeContext.Name> TensorType type(TypeContext<NAMETYPE> context);
 
     /** Evaluate with no context */
     public final Tensor evaluate() { return evaluate(new MapEvaluationContext()); }
@@ -58,7 +58,7 @@ public abstract class TensorFunction {
     /**
      * Return a string representation of this context.
      *
-     * @param context a context which must be passed to all nexted functions when requesting the string value
+     * @param context a context which must be passed to all nested functions when requesting the string value
      */
     public abstract String toString(ToStringContext context);
 
diff --git a/vespajlib/src/test/java/com/yahoo/tensor/functions/ConcatTestCase.java b/vespajlib/src/test/java/com/yahoo/tensor/functions/ConcatTestCase.java
index 7e1f292eb7b..eafa5c4addf 100644
--- a/vespajlib/src/test/java/com/yahoo/tensor/functions/ConcatTestCase.java
+++ b/vespajlib/src/test/java/com/yahoo/tensor/functions/ConcatTestCase.java
@@ -2,6 +2,9 @@
 package com.yahoo.tensor.functions;
 
 import com.yahoo.tensor.Tensor;
+import com.yahoo.tensor.TensorType;
+import com.yahoo.tensor.evaluation.MapEvaluationContext;
+import com.yahoo.tensor.evaluation.TypeContext;
 import org.junit.Test;
 
 import static org.junit.Assert.assertEquals;
@@ -16,51 +19,98 @@ public class ConcatTestCase {
     public void testConcatNumbers() {
         Tensor a = Tensor.from("{1}");
         Tensor b = Tensor.from("{2}");
-        assertEquals(Tensor.from("tensor(x[2]):{ {x:0}:1, {x:1}:2 }"), a.concat(b, "x"));
-        assertEquals(Tensor.from("tensor(x[2]):{ {x:0}:2, {x:1}:1 }"), b.concat(a, "x"));
+        assertConcat("tensor(x[2]):{ {x:0}:1, {x:1}:2 }", a, b, "x");
+        assertConcat("tensor(x[2]):{ {x:0}:2, {x:1}:1 }", b, a , "x");
     }
 
     @Test
     public void testConcatEqualShapes() {
-        Tensor a = Tensor.from("tensor(x[]):{ {x:0}:1, {x:1}:2, {x:2}:3 }");
-        Tensor b = Tensor.from("tensor(x[]):{ {x:0}:4, {x:1}:5, {x:2}:6 }");
-        assertEquals(Tensor.from("tensor(x[6]):{ {x:0}:1, {x:1}:2, {x:2}:3, {x:3}:4, {x:4}:5, {x:5}:6 }"), a.concat(b, "x"));
-        assertEquals(Tensor.from("tensor(x[3],y[2]):{ {x:0,y:0}:1, {x:1,y:0}:2, {x:2,y:0}:3, " +
-                                 "{x:0,y:1}:4, {x:1,y:1}:5, {x:2,y:1}:6  }"), a.concat(b, "y"));
+        Tensor a = Tensor.from("tensor(x[3]):{ {x:0}:1, {x:1}:2, {x:2}:3 }");
+        Tensor b = Tensor.from("tensor(x[3]):{ {x:0}:4, {x:1}:5, {x:2}:6 }");
+        assertConcat("tensor(x[6]):{ {x:0}:1, {x:1}:2, {x:2}:3, {x:3}:4, {x:4}:5, {x:5}:6 }", a, b, "x");
+        assertConcat("tensor(x[3],y[2]):{ {x:0,y:0}:1, {x:1,y:0}:2, {x:2,y:0}:3, " +
+                                                   "{x:0,y:1}:4, {x:1,y:1}:5, {x:2,y:1}:6  }",
+                     a, b, "y");
     }
 
     @Test
     public void testConcatNumberAndVector() {
         Tensor a = Tensor.from("{1}");
+        Tensor b = Tensor.from("tensor(x[3]):{ {x:0}:2, {x:1}:3, {x:2}:4 }");
+        assertConcat("tensor(x[4]):{ {x:0}:1, {x:1}:2, {x:2}:3, {x:3}:4 }", a, b, "x");
+        assertConcat("tensor(x[3],y[2]):{ {x:0,y:0}:1, {x:1,y:0}:1, {x:2,y:0}:1, " +
+                                                  "{x:0,y:1}:2, {x:1,y:1}:3, {x:2,y:1}:4  }",
+                     a, b, "y");
+    }
+
+    @Test
+    public void testConcatNumberAndVectorUnbound() {
+        Tensor a = Tensor.from("{1}");
         Tensor b = Tensor.from("tensor(x[]):{ {x:0}:2, {x:1}:3, {x:2}:4 }");
-        assertEquals(Tensor.from("tensor(x[4]):{ {x:0}:1, {x:1}:2, {x:2}:3, {x:3}:4 }"), a.concat(b, "x"));
-        assertEquals(Tensor.from("tensor(x[3],y[2]):{ {x:0,y:0}:1, {x:1,y:0}:1, {x:2,y:0}:1, " +
-                                 "{x:0,y:1}:2, {x:1,y:1}:3, {x:2,y:1}:4  }"), a.concat(b, "y"));
+        assertConcat("tensor(x[])","tensor(x[4]):{ {x:0}:1, {x:1}:2, {x:2}:3, {x:3}:4 }", a, b, "x");
+        assertConcat("tensor(x[],y[2])", "tensor(x[3],y[2]):{ {x:0,y:0}:1, {x:1,y:0}:1, {x:2,y:0}:1, " +
+                     "{x:0,y:1}:2, {x:1,y:1}:3, {x:2,y:1}:4  }",
+                     a, b, "y");
     }
 
     @Test
     public void testUnequalSizesSameDimension() {
+        Tensor a = Tensor.from("tensor(x[2]):{ {x:0}:1, {x:1}:2 }");
+        Tensor b = Tensor.from("tensor(x[3]):{ {x:0}:4, {x:1}:5, {x:2}:6 }");
+        assertConcat("tensor(x[5]):{ {x:0}:1, {x:1}:2, {x:2}:4, {x:3}:5, {x:4}:6 }", a, b, "x");
+        assertConcat("tensor(x[2],y[2]):{ {x:0,y:0}:1, {x:1,y:0}:2, {x:0,y:1}:4, {x:1,y:1}:5 }", a, b,"y");
+    }
+
+    @Test
+    public void testUnequalSizesSameDimensionUnbound() {
         Tensor a = Tensor.from("tensor(x[]):{ {x:0}:1, {x:1}:2 }");
         Tensor b = Tensor.from("tensor(x[]):{ {x:0}:4, {x:1}:5, {x:2}:6 }");
-        assertEquals(Tensor.from("tensor(x[5]):{ {x:0}:1, {x:1}:2, {x:2}:4, {x:3}:5, {x:4}:6 }"), a.concat(b, "x"));
-        assertEquals(Tensor.from("tensor(x[2],y[2]):{ {x:0,y:0}:1, {x:1,y:0}:2, {x:0,y:1}:4, {x:1,y:1}:5 }"), a.concat(b, "y"));
+        assertConcat("tensor(x[])", "tensor(x[5]):{ {x:0}:1, {x:1}:2, {x:2}:4, {x:3}:5, {x:4}:6 }", a, b, "x");
+        assertConcat("tensor(x[],y[2])", "tensor(x[2],y[2]):{ {x:0,y:0}:1, {x:1,y:0}:2, {x:0,y:1}:4, {x:1,y:1}:5 }", a, b,"y");
     }
 
     @Test
     public void testUnequalEqualSizesDifferentDimension() {
+        Tensor a = Tensor.from("tensor(x[2]):{ {x:0}:1, {x:1}:2 }");
+        Tensor b = Tensor.from("tensor(y[3]):{ {y:0}:4, {y:1}:5, {y:2}:6 }");
+        assertConcat("tensor(x[3],y[3]):{{x:0,y:0}:1.0,{x:0,y:1}:1.0,{x:0,y:2}:1.0,{x:1,y:0}:2.0,{x:1,y:1}:2.0,{x:1,y:2}:2.0,{x:2,y:0}:4.0,{x:2,y:1}:5.0,{x:2,y:2}:6.0}", a, b, "x");
+        assertConcat("tensor(x[2],y[4]):{{x:0,y:0}:1.0,{x:0,y:1}:4.0,{x:0,y:2}:5.0,{x:0,y:3}:6.0,{x:1,y:0}:2.0,{x:1,y:1}:4.0,{x:1,y:2}:5.0,{x:1,y:3}:6.0}", a, b, "y");
+        assertConcat("tensor(x[2],y[3],z[2]):{{x:0,y:0,z:0}:1.0,{x:0,y:0,z:1}:4.0,{x:0,y:1,z:0}:1.0,{x:0,y:1,z:1}:5.0,{x:0,y:2,z:0}:1.0,{x:0,y:2,z:1}:6.0,{x:1,y:0,z:0}:2.0,{x:1,y:0,z:1}:4.0,{x:1,y:1,z:0}:2.0,{x:1,y:1,z:1}:5.0,{x:1,y:2,z:0}:2.0,{x:1,y:2,z:1}:6.0}", a, b, "z");
+    }
+
+    @Test
+    public void testUnequalEqualSizesDifferentDimensionOneUnbound() {
         Tensor a = Tensor.from("tensor(x[]):{ {x:0}:1, {x:1}:2 }");
-        Tensor b = Tensor.from("tensor(y[]):{ {y:0}:4, {y:1}:5, {y:2}:6 }");
-        assertEquals(Tensor.from("tensor(x[3],y[3]):{{x:0,y:0}:1.0,{x:0,y:1}:1.0,{x:0,y:2}:1.0,{x:1,y:0}:2.0,{x:1,y:1}:2.0,{x:1,y:2}:2.0,{x:2,y:0}:4.0,{x:2,y:1}:5.0,{x:2,y:2}:6.0}"), a.concat(b, "x"));
-        assertEquals(Tensor.from("tensor(x[2],y[4]):{{x:0,y:0}:1.0,{x:0,y:1}:4.0,{x:0,y:2}:5.0,{x:0,y:3}:6.0,{x:1,y:0}:2.0,{x:1,y:1}:4.0,{x:1,y:2}:5.0,{x:1,y:3}:6.0}"), a.concat(b, "y"));
-        assertEquals(Tensor.from("tensor(x[2],y[3],z[2]):{{x:0,y:0,z:0}:1.0,{x:0,y:0,z:1}:4.0,{x:0,y:1,z:0}:1.0,{x:0,y:1,z:1}:5.0,{x:0,y:2,z:0}:1.0,{x:0,y:2,z:1}:6.0,{x:1,y:0,z:0}:2.0,{x:1,y:0,z:1}:4.0,{x:1,y:1,z:0}:2.0,{x:1,y:1,z:1}:5.0,{x:1,y:2,z:0}:2.0,{x:1,y:2,z:1}:6.0}"), a.concat(b, "z"));
+        Tensor b = Tensor.from("tensor(y[3]):{ {y:0}:4, {y:1}:5, {y:2}:6 }");
+        assertConcat("tensor(x[],y[3])", "tensor(x[3],y[3]):{{x:0,y:0}:1.0,{x:0,y:1}:1.0,{x:0,y:2}:1.0,{x:1,y:0}:2.0,{x:1,y:1}:2.0,{x:1,y:2}:2.0,{x:2,y:0}:4.0,{x:2,y:1}:5.0,{x:2,y:2}:6.0}", a, b, "x");
+        assertConcat("tensor(x[],y[4])", "tensor(x[2],y[4]):{{x:0,y:0}:1.0,{x:0,y:1}:4.0,{x:0,y:2}:5.0,{x:0,y:3}:6.0,{x:1,y:0}:2.0,{x:1,y:1}:4.0,{x:1,y:2}:5.0,{x:1,y:3}:6.0}", a, b, "y");
+        assertConcat("tensor(x[],y[3],z[2])", "tensor(x[2],y[3],z[2]):{{x:0,y:0,z:0}:1.0,{x:0,y:0,z:1}:4.0,{x:0,y:1,z:0}:1.0,{x:0,y:1,z:1}:5.0,{x:0,y:2,z:0}:1.0,{x:0,y:2,z:1}:6.0,{x:1,y:0,z:0}:2.0,{x:1,y:0,z:1}:4.0,{x:1,y:1,z:0}:2.0,{x:1,y:1,z:1}:5.0,{x:1,y:2,z:0}:2.0,{x:1,y:2,z:1}:6.0}", a, b, "z");
     }
 
     @Test
     public void testDimensionsubset() {
         Tensor a = Tensor.from("tensor(x[],y[]):{ {x:0,y:0}:1, {x:1,y:0}:2, {x:0,y:1}:3, {x:1,y:1}:4 }");
         Tensor b = Tensor.from("tensor(y[2]):{ {y:0}:5, {y:1}:6 }");
-        assertEquals(Tensor.from("tensor(x[3],y[2]):{{x:0,y:0}:1.0,{x:0,y:1}:3.0,{x:1,y:0}:2.0,{x:1,y:1}:4.0,{x:2,y:0}:5.0,{x:2,y:1}:6.0}"), a.concat(b, "x"));
-        assertEquals(Tensor.from("tensor(x[2],y[4]):{{x:0,y:0}:1.0,{x:0,y:1}:3.0,{x:0,y:2}:5.0,{x:0,y:3}:6.0,{x:1,y:0}:2.0,{x:1,y:1}:4.0,{x:1,y:2}:5.0,{x:1,y:3}:6.0}"), a.concat(b, "y"));
+        assertConcat("tensor(x[],y[])", "tensor(x[3],y[2]):{{x:0,y:0}:1.0,{x:0,y:1}:3.0,{x:1,y:0}:2.0,{x:1,y:1}:4.0,{x:2,y:0}:5.0,{x:2,y:1}:6.0}", a, b, "x");
+        assertConcat("tensor(x[],y[])", "tensor(x[2],y[4]):{{x:0,y:0}:1.0,{x:0,y:1}:3.0,{x:0,y:2}:5.0,{x:0,y:3}:6.0,{x:1,y:0}:2.0,{x:1,y:1}:4.0,{x:1,y:2}:5.0,{x:1,y:3}:6.0}", a, b, "y");
+    }
+
+    private void assertConcat(String expected, Tensor a, Tensor b, String dimension) {
+        assertConcat(null, expected, a, b, dimension);
+    }
+
+    private void assertConcat(String expectedType, String expected, Tensor a, Tensor b, String dimension) {
+        Tensor expectedAsTensor = Tensor.from(expected);
+        TensorType inferredType = new Concat(new ConstantTensor(a), new ConstantTensor(b), dimension)
+                                           .type(new MapEvaluationContext());
+        Tensor result = a.concat(b, dimension);
+
+        if (expectedType != null)
+            assertEquals(TensorType.fromSpec(expectedType), inferredType);
+        else
+            assertEquals(expectedAsTensor.type(), inferredType);
+
+        assertEquals(expectedAsTensor, result);
     }
 
 }