Speciel pontosan ő is ezt mondja:
https://www.martinfowler.com/bliki/FunctionLength.html
"The argument that makes most sense to me, however, is the separation between intention and implementation. If you have to spend effort into looking at a fragment of code to figure out what it's doing, then you should extract it into a function and name the function after that “what”. That way when you read it again, the purpose of the function leaps right out at you, and most of the time you won't need to care about how the function fulfills its purpose - which is the body of the function."
A kiemelt résznek pont a lényege, hogy egy függvény tartalmazzon egy absztrakciós szintet - ne a hogyant, hanem a mit írja le. Majd az eggyel alacsonyabb absztrakciós szint leírja a hogyant.
És ő pont ebből vezeti le, hogy ha ezt az elvet tartod szem előtt, akkor baromi rövid függvényeid lesznek. Hogy úgy mondjam, ez csak egy side effect. Egy példát is mutat erre:
"The fact that size isn't important was brought home to me by an example that Kent Beck showed me from the original Smalltalk system. Smalltalk in those days ran on black-and-white systems. If you wanted to highlight some text or graphics, you would reverse the video. Smalltalk's graphics class had a method for this called 'highlight', whose implementation was just a call to the method 'reverse'. The name of the method was longer than its implementation - but that didn't matter because there was a big distance between the intention of the code and its implementation."
Létezett egy függvény, a highlight, amely csak egy reverse-t hívott, egy sorosan. A lényeg az volt, hogy a highlight mint absztrakció létezett a rendszerben, és ahol kellett, ott highlight-ot hívtál, nem közvetelnül reverse-t, és nem is kellett tudnod, hogy a highlight implementációja egy reverse valójában.
Majd ugyanitt
"Small functions like this only work if the names are good, so you need to pay good attention to naming. This takes practice, but once you get good at it, this approach can make code remarkably self-documenting. Larger scale functions can read like a story, and the reader can choose which functions to dive into for more detail as she needs it."
Megint ugyanaz az elv: a függvény egy story.