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    Mutable let bindings in Reason

    Nik GrafNik Graf

    Immutability comes with lots of benefits. Working with a programming language with first class immutable data structures is a blaze. Nevertheless sometimes it can be useful to have a binding that's mutable. Using references we can achieve this in ReasonML.



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    Instructor: 00:01 Let bindings are mutable by default. We can make them mutable using a reference to wrap the actual value. Basically, a reference is like a box, and the content inside can change.

    00:13 To update the reference, we can use a column followed by an equals sign. We here refer to the name. The content of our foo changed to six.

    00:22 In order to retrieve the value of a reference, we can use the carrot character. References, for example, can be used to store the state of the whole game where you are, like this.

    00:49 Keep in mind to use this feature sparingly to avoid unexpected behavior. Immutability comes with lots of benefits, and you better not give them up without any good reasons.