Initialize gradle project

1 files changed, 116 insertions, 0 deletions

diff --git a/src/main/java/pl/edu/mimuw/cloudatlas/model/TypeCollection.java b/src/main/java/pl/edu/mimuw/cloudatlas/model/TypeCollection.java
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+/**
+ * Copyright (c) 2014, University of Warsaw
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without modification, are permitted
+ * provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice, this list of
+ * conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright notice, this list of
+ * conditions and the following disclaimer in the documentation and/or other materials provided
+ * with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR
+ * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
+ * FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR
+ * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
+ * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY
+ * WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+package pl.edu.mimuw.cloudatlas.model;
+
+import java.util.Collection;
+
+import pl.edu.mimuw.cloudatlas.model.Type;
+import pl.edu.mimuw.cloudatlas.model.TypePrimitive;
+import pl.edu.mimuw.cloudatlas.model.Value;
+import pl.edu.mimuw.cloudatlas.model.ValueNull;
+
+/**
+ * Represents a collection type with a specified element type.
+ *
+ * @see TypePrimitve
+ */
+public class TypeCollection extends Type {
+    private final Type elementType;
+
+    /**
+     * Creates a new collection type.
+     *
+     * @param primaryType a type of this collection (set, list etc.)
+     * @param elementType a type of elements of this collection; may be a complex type (for instance
+     * another <code>TypeCollection</code>)
+     */
+    public TypeCollection(PrimaryType primaryType, Type elementType) {
+        super(primaryType);
+        switch(primaryType) {
+            case LIST:
+            case SET:
+                break;
+            default:
+                throw new IllegalArgumentException("This class can represent a collection only (list, set etc.).");
+        }
+        this.elementType = elementType;
+    }
+
+    /**
+     * Gets a type of elements stored in this collection.
+     *
+     * @return type of element in this collection
+     */
+    public Type getElementType() {
+        return elementType;
+    }
+
+    /**
+     * Returns a textual representation of this collection, for instance: "SET of (STRING)".
+     *
+     * @return a textual representation of this type
+     */
+    @Override
+    public String toString() {
+        return getPrimaryType().toString() + " of (" + elementType.toString() + ")";
+    }
+
+    @Override
+    public boolean isCompatible(Type type) {
+        return super.isCompatible(type)
+                || (getPrimaryType() == type.getPrimaryType() && elementType
+                        .isCompatible(((TypeCollection)type).elementType));
+    }
+
+    @Override
+    public boolean isCollection() {
+        return true;
+    }
+
+    /**
+     * Returns a type of all elements in the specified collection. If the collection is empty, this method returns
+     * {@link TypePrimitive#NULL}. If the collection contains at least two elements of distinct types that are not nulls,
+     * an exception is thrown.
+     *
+     * @param collection a collection of values to check
+     * @return type of elements in this collection
+     * @throws IllegalArgumentException if the collection contains non-null elements of different types
+     */
+    public static Type computeElementType(Collection<Value> collection) {
+        Type mainType = null;
+
+        for(Value v : collection) {
+            if(v.isNull())
+                v = ValueNull.getInstance();
+            if(mainType == null) {
+                if(v.getType().getPrimaryType() != Type.PrimaryType.NULL)
+                    mainType = v.getType();
+            } else if(!mainType.isCompatible(v.getType()))
+                throw new IllegalArgumentException("Collection has non-null elements of different types.");
+        }
+
+        return mainType == null? TypePrimitive.NULL : mainType;
+    }
+}