November 2017
Intermediate to advanced
670 pages
17h 35m
English
Content preview from Learning Functional Programming in Go
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What are not monoids?
Integers are not monoids, but integers under addition (a way to combine them) are monoids.
Whole numbers (integers starting at 1), and even whole numbers under addition, are not monoids. What is the neutral element for addition? The answer is zero.
Invoices are not monoids:
How can we combine two invoices?
What does it mean to add invoices? Are we going to merge the colors or somehow smash them together? If we stack them, how can we do anything with them, other than take the top one off the list? How do we combine the ...