Added KotlinVersion.kt

runtime/src/main/kotlin/kotlin/KotlinVersion.kt

@@ -0,0 +1,89 @@
+/*
+ * Copyright 2010-2017 JetBrains s.r.o.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package kotlin
+
+/**
+ * Represents a version of the Kotlin standard library.
+ *
+ * [major], [minor] and [patch] are integer components of a version,
+ * they must be non-negative and not greater than 255 ([MAX_COMPONENT_VALUE]).
+ *
+ * @constructor Creates a version from all three components.
+ */
+public class KotlinVersion(val major: Int, val minor: Int, val patch: Int) : Comparable<KotlinVersion> {
+    /**
+     * Creates a version from [major] and [minor] components, leaving [patch] component zero.
+     */
+    public constructor(major: Int, minor: Int) : this(major, minor, 0)
+
+    private val version = versionOf(major, minor, patch)
+
+    private fun versionOf(major: Int, minor: Int, patch: Int): Int {
+        require(major in 0..MAX_COMPONENT_VALUE && minor in 0..MAX_COMPONENT_VALUE && patch in 0..MAX_COMPONENT_VALUE) {
+            "Version components are out of range: $major.$minor.$patch"
+        }
+        return major shl 16 + minor shl 8 + patch
+    }
+
+    /**
+     * Returns the string representation of this version
+     */
+    override fun toString(): String = "$major.$minor.$patch"
+
+    override fun equals(other: Any?): Boolean {
+        if (this === other) return true
+        val otherVersion = (other as? KotlinVersion) ?: return false
+        return this.version == otherVersion.version
+    }
+
+    override fun hashCode(): Int = version
+
+    override fun compareTo(other: KotlinVersion): Int = version - other.version
+
+    /**
+     * Returns `true` if this version is not less than the version specified
+     * with the provided [major] and [minor] components.
+     */
+    public fun isAtLeast(major: Int, minor: Int): Boolean =
+            // or this.version >= versionOf(major, minor, 0)
+            this.major > major || (this.major == major &&
+                    this.minor >= minor)
+
+    /**
+     * Returns `true` if this version is not less than the version specified
+     * with the provided [major], [minor] and [patch] components.
+     */
+    public fun isAtLeast(major: Int, minor: Int, patch: Int): Boolean =
+            // or this.version >= versionOf(major, minor, patch)
+            this.major > major || (this.major == major &&
+                    (this.minor > minor || this.minor == minor &&
+                            this.patch >= patch))
+
+    companion object {
+        /**
+         * Maximum value a version component can have, a constant value 255.
+         */
+        // NOTE: Must be placed before CURRENT because its initialization requires this field being initialized in JS
+        public const val MAX_COMPONENT_VALUE = 255
+
+        /**
+         * Returns the current version of the Kotlin standard library.
+         */
+        // TODO: get from metadata or hardcode automatically during build
+        public val CURRENT: KotlinVersion = KotlinVersion(1, 1, 4)
+    }
+}