libwren-sys 0.1.0

// Infix.
System.print(5 - 3)      // expect: 2
System.print(3.1 - 0.24) // expect: 2.86
System.print(3 - 2 - 1)  // expect: 0

// Unary negation.
var a = 3
System.print(-a) // expect: -3