List and Map constructor coercion in Groovy

gistfile1.groovy

import groovy.transform.Immutable

@Immutable
class Point {
    double x, y
}

Point p1 = [1.23, 5.67]
assert p1.x == 1.23 && p1.y == 5.67

Point p2 = [y: 10, x: -1]
assert p2.x == -1 && p2.y == 10

Some further examples in MrHaki's blog post:
http://mrhaki.blogspot.nl/2009/09/groovy-goodness-using-lists-and-maps-as.html