alt Hacker NewsFrom the article as well:
Side-Effect Prevention When a null-conditional statement assignment is evaluated, the right-hand side of the expression is not executed unless the left-hand side is defined.
From the article as well:
Side-Effect Prevention When a null-conditional statement assignment is evaluated, the right-hand side of the expression is not executed unless the left-hand side is defined.
Thanks. I missed it.
I really dislike that, because it hides the control flow too much. Perhaps I'm biased by Racket, where it's easy to define something weird using macros, but you should not do unexpected weird things.
For example you can define vector-set/drop that writes a value to a position of a vector, but ignores the operation when the position is outside the vector. For example
With a macro is possible to skip (print "banana") because -2 is clearly out of range, but if you do that everyone will hate you.