I am currently busy learning Terraform. However, when I reached lesson 3 of the tutorial, my IDE gave the following error when changing infrastructure on AWS:
I think the intent of the author of this guide was not that you copy the - and + literally into your file, but rather that you treat those symbols as a guide for what to change: remove the ami = "ami-830c94e3" line and insert ami = "ami-08d70e59c07c61a3a" in place of it.
That would then leave you with the following, which is valid Terraform syntax: