why can quotes be left out in names of gradle tasks - gradle

Question

I don't understand why we don't need to add quotes to the name of gradle task when we declare it
like:
task hello (type : DefaultTask) {
}
I've tried in a groovy project and found that it's illegal, how gradle makes it works.
And I don't understand the expression above neither, why we can add (type : DefaultTask), how can we analyze it with groovy grammar?

Answer 1

As an example in a GroovyConsole runnable form, you can define a bit of code thusly:
// Set the base class for our DSL
#BaseScript(MyDSL)
import groovy.transform.BaseScript
// Something to deal with people
class Person {
String name
Closure method
String toString() { "$name" }
Person(String name, Closure cl) {
this.name = name
this.method = cl
this.method.delegate = this
}
def greet(String greeting) {
println "$greeting $name"
}
}
// and our base DSL class
abstract class MyDSL extends Script {
def methodMissing(String name, args) {
return new Person(name, args[0])
}
def person(Person p) {
p.method(p)
}
}
// Then our actual script
person tim {
greet 'Hello'
}
So when the script at the bottom is executed, it prints Hello tim to stdout
But David's answer is the correct one, this is just for example
See also here in the documentation for Groovy

Answer 2

A Gradle build script is a Groovy DSL application. By careful use of "methodMissing" and "propertyMissing" methods, all magic is possible.
I don't remember the exact mechanism around "task ". I think this was asked in the Gradle forum (probably more than once).

Answer 3

Here is the code that make the magic possible and legal.
// DSL class - Gradle Task
class Task {
def name;
}
// DSL class - Gradle Project
class Project {
List<Task> tasks = [];
def methodMissing(String name, def args) {
if(name == "task"){
Task t = new Task(name:args[0])
tasks << t
}
}
def propertyMissing(String name) {
name
}
}
// gradle build script
def buildScript = {
task myTask
println tasks[0].name
}
buildScript.delegate = new Project()
// calling the script will print out "myTask"
buildScript()