How values make systems simpler
Distinguishing between stateful Objects and Values has long been recognized
as fruitful. Values are universal context-free abstractions that prevent
side-effects and allow for a functional programming style. Though
programming languages provide simple Values like Integer and String, more
complex Values are usually not supported. We show how to model complex
structures as Values in Smalltalk, which allows for a simple and versatile
implementation. The resulting Smalltalk systems are simple, clear and
easily testable.
Christian Haider
https://www.blogger.com/blog/post/edit/6836728665332319456/1027115540446033573#
is
the author of the PDFtalk
https://www.blogger.com/blog/post/edit/6836728665332319456/1027115540446033573#
library
used in smallCharts
https://www.blogger.com/blog/post/edit/6836728665332319456/1027115540446033573#
and
other projects. Underlying is a simple implementation of Values
https://www.blogger.com/blog/post/edit/6836728665332319456/1027115540446033573#
which
he uses extensibly.
Christian will show how Values make systems simpler and easier. Examples
for some uses and the limits of the approach will be discussed.
Since Values use only standard Smalltalk features, it can be used in most
other Smalltalks. And all of this code is available with MIT licence.
This will be an online meeting from home. If you'd like to join us, please
sign up in advance on https://www.meetup.com/ukstug/events/302453141