in 6.3. Concise Control Flow with if let there is a typo

[KianMehrabi]

this line

the part i have problem with

the corresponding match arm. The code in the if let block isn’t run if the
value doesn’t match the pattern.

after isn’t there is missing going to

[chriskrycho]

Ah, this is a quirky bit of English—the combination of the contraction with a slightly less common construction. It is saying “The code in the if let block is not run [by the program when it executes] if the value does not match the pattern.” I think changing from “isn’t run” to “will not be run” is probably a reasonable change here, if you’d like to open a PR to do that!