new features:
type student struct {
name string
score int
}
a := [student{"du", 84}, student{"wang", 70}, student{"ken", 100}]
hasFullMark := {for x <- a, x.score == 100}
println("is any student full mark:", hasFullMark)
hasFailed := {for x <- a, x.score < 60}
println("is any student failed:", hasFailed)