R programming is from S, influenced by APL

History of data science tools has evolved to #rstats of the 1990s, from the S-Language at Bell Labs in the 1970s, and the <- arrow symbols came from #APL (A Programming Language) in the 1960s.

As you all know, R comes from S. But you might not know a lot about S (I don’t). This language used <- as an assignment operator. It’s partly because it was inspired by a language called APL, which also had this sign for assignment.

But why again? APL was designed on a specific keyboard, which had a key for<-:

“Why do we use arrow as an assignment operator?” | Colin Fay | September 24, 2018 at https://colinfay.me/r-assignment/

In the mid-1980s, I worked primarily in APL, with the special character set keyboard.

By User:Rursus – APL-keybd.svg, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=2456412

I was curious about this, because I saw the alternative to <- with an “assign” function.

A more laborious, though sometimes necessary, way to assign variables is to use the assign function.

assign(“j”, 4)
[1] 4

4.2.1. Variable Assignment” | Jared P. Lander | R for Everyone: Advanced Analytics and Graphics

This suggests that an alternative to using the arrow is a more functional style of programming.


#apl-a-programming-language, #r-programming, #s-programming-language