什么是"implementation deps.support.app_compat"中的"deps"？

Question

我正在查看google示例中的新架构组件,在那里我找到了如下代码:

dependencies {
    // Support libraries
    implementation deps.support.app_compat
    implementation deps.support.v4
    implementation deps.support.design
    implementation deps.support.cardview

    // Architecture components
    implementation deps.lifecycle.runtime
    implementation deps.lifecycle.extensions
    annotationProcessor deps.lifecycle.compiler
    implementation deps.room.runtime
    annotationProcessor deps.room.compiler

    // Android Testing Support Library's runner and rules
    androidTestImplementation deps.atsl.runner
    androidTestImplementation deps.atsl.rules
    androidTestImplementation deps.room.testing
    androidTestImplementation deps.arch_core.testing

    // Espresso UI Testing
    androidTestImplementation deps.espresso.core
    androidTestImplementation deps.espresso.contrib
    androidTestImplementation deps.espresso.intents

    // Resolve conflicts between main and test APK:
    androidTestImplementation deps.support.annotations
    androidTestImplementation deps.support.v4
    androidTestImplementation deps.support.app_compat
    androidTestImplementation deps.support.design
}

我无法理解为什么他们写了所有的依赖开头deps.*.任何人都可以帮我理解代码.提前致谢.这是回购的链接.

Answer 1

deps是在实例上Map设置project并在versions.gradle文件中定义的类的实例.此versions.gradle文件又应用于根build.gradle脚本,因此deps可以在子项目中使用.