Reading and Writing Fields

Flix supports reading object fields and static (class) fields with standard Java syntax.

We can read an object field as follows:

import java.awt.Point

def area(p: Point): Int32 \ IO = unsafe (p.x * p.y)

We can read a static field as follows:

import java.lang.Math

def area(radius: Float64): Float64 = (unsafe Math.PI) * radius * radius

We import the java.lang.Math class and then we access the static PI field.

We know that the PI field will never change, hence we cast away the effect with unsafe.

Flix supports writing to an object field with the non-standard syntax:

import java_set_field foo.bar.Baz.boolField: Unit \ IO as setField;
let o = ...;
setField(o, false)

Here the import expression creates a function named setField which we call.

Note: We are currently working on a more tolerable syntax.

Flix supports writing to a static field with the non-standard syntax:

import static java_set_field foo.bar.Baz.StaticBoolField: Unit \ IO as setField;
let o = ...;
setField(o, false)

Note: We are currently working on a more tolerable syntax.

Here the import expression creates a function named setField which we call.