Programming Flix

Reading and Writing Fields

We can read and write fields by importing functions that serve as "getters" and "setters".

Assume we have the Java class:

class TestClass {
    boolean boolField = true;
}

Then here is how we can access the boolField:

import java_new flix.test.TestClass(): ##flix.test.TestClass \ IO as newObject;
import java_get_field flix.test.TestClass.boolField: Bool \ IO as getField;
let o = newObject();
getField(o)

Here we import the (default, empty) constructor of TestClass as newObject. Next, we import the field boolField as the function getField. We use newObject to construct a fresh object and we call getField on it to obtain the value of o.boolField.

Writing a field of an object is similar:

import java_new flix.test.TestClass(): ##flix.test.TestClass \ IO as newObject;
import java_get_field flix.test.TestClass.boolField: Bool \ IO as getField;
import java_set_field flix.test.TestClass.boolField: Unit \ IO as setField;
let o = newObject();
setField(o, false);
getField(o)

Here we import both a "getter" and "setter" for the boolField field.

Reading and Writing Static Fields

Reading or writing static fields is similar to reading or writing object fields. For example:

import static java_get_field java.lang.Integer.MIN_VALUE: Int32 \ IO as getMinValue;
getMinValue()

The only difference is to write the static keyword to indicate that the reference is to a static field.