Include loader's basic version parser, adds support for new yarn version separator

src/main/java/net/fabricmc/loom/providers/MappingsProvider.java

@@ -27,6 +27,7 @@ package net.fabricmc.loom.providers;
 import net.fabricmc.loom.LoomGradleExtension;
 import net.fabricmc.loom.util.Constants;
 import net.fabricmc.loom.util.DependencyProvider;
+import net.fabricmc.loom.util.Version;
 import net.fabricmc.stitch.commands.CommandProposeFieldNames;
 import org.gradle.api.Project;
 
@@ -62,10 +63,10 @@ public class MappingsProvider extends DependencyProvider {
 		File mappingsJar = dependency.resolveFile().orElseThrow(() -> new RuntimeException("Could not find dependency " + dependency));
 
 		this.mappingsName = dependency.getDependency().getName();
-		char verSep = version.contains("-") ? '-' : '.';
 
-		this.minecraftVersion = version.substring(0, version.lastIndexOf(verSep));
+		Version mappingsVersion = new Version(version);
-		this.mappingsVersion = version.substring(version.lastIndexOf(verSep) + 1);
+		this.minecraftVersion = mappingsVersion.getMinecraftVersion();
+		this.mappingsVersion = mappingsVersion.getMappingsVersion();
 
 		initFiles(project);
 

src/main/java/net/fabricmc/loom/util/Version.java

@@ -0,0 +1,60 @@
+/*
+ * This file is part of fabric-loom, licensed under the MIT License (MIT).
+ *
+ * Copyright (c) 2016, 2017, 2018 FabricMC
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+package net.fabricmc.loom.util;
+
+public class Version {
+
+	private String mappingsVersion;
+	private String minecraftVersion;
+
+	private String version;
+
+	public Version(String version) {
+		this.version = version;
+
+		if(version.contains("+build.")){
+			this.minecraftVersion = version.substring(0, version.lastIndexOf('+'));
+			this.mappingsVersion = version.substring(version.lastIndexOf('.') + 1);
+		} else {
+			//TODO legacy remove when no longer needed
+			char verSep = version.contains("-") ? '-' : '.';
+			this.minecraftVersion = version.substring(0, version.lastIndexOf(verSep));
+			this.mappingsVersion = version.substring(version.lastIndexOf(verSep) + 1);
+		}
+	}
+
+	public String getMappingsVersion() {
+		return mappingsVersion;
+	}
+
+	public String getMinecraftVersion() {
+		return minecraftVersion;
+	}
+
+	@Override
+	public String toString() {
+		return version;
+	}
+}