[erlang-questions] guard clause oddity, maybe bug (in my brain)?

Kenneth Lakin kennethlakin@REDACTED
Sat Nov 21 07:16:52 CET 2015

On 11/20/2015 08:27 PM, Jim wrote:
> Thank you both, I guess I don't  fully understand the associative and precedence of these operators.

This seems a sensible way to look at it:

1> false andalso false orelse true.
2> ((false andalso false) orelse true).
3> (false andalso (false orelse true)).

andalso and orelse are described in the docs as

Expr1 orelse Expr2
Expr1 andalso Expr2

You *have* to have two expressions for a given andalso/orelse, so you
read expression 1 up there from left to right.
First evaluate
false andalso false (which is -obviously- false, and becomes the Expr1
of the next expression)
Then evalutate
false orelse true (which is true)

Does that make sense?

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