Mapping Out Lambda Land: An Introduction to Functional Programming by Katie Miller.
From the post:
Anyone who has met me will probably know that I am wildly enthusiastic about functional programming (FP). I co-founded a group for women in FP, have presented a series of talks and workshops about functional concepts, and have even been known to create lambda-branded clothing and jewellery. In this blog post, I will try to give some insight into what the fuss is about. I will briefly explain what functional programming is, why you should care, and how you can use OpenShift to learn more about FP.
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Good introduction to functional programming and resources on using OpenShift to learn FP.
Just in case you don’t recognize the name, Katie is the author of Lingo of Lamda Land, a poem depending on who is reading it.