How to read log output of NSAutoresizingMaskLayoutConstraint?

Question

I see the following output in console

"<NSAutoresizingMaskLayoutConstraint:0x100510500 h=--& v=&-- H:|-(0)-[NSView]
    (Names: NSView:0x1016ab760, '|':NSClipView:0x1016a26b0 )>
    (Actual Distance - pixels):0"

Normally I understand how to read log message for constraints. But autoresizingMask constraints always confuse me. How does the following characters in the log output correspond to auto-resizing mask?

h=--& v=&-- H:|-(0)-[NSView]

I watched several WWDC 2012 videos which didn't quite explain reading auto-resizing mask layout constraints.

Answer 1

jrturton describes the first part of the debugging output in his answer (see the comments)

h=--& v=&--

The second part is the same for all autolayout constraints:

H:|-(0)-[NSView]

This is just giving details on how the mask got turned into a constraint. "H" means horizontal, the "|" means the container your view is in (in this case an NSClipView), the -(0)- means that it's constrained to be 0 pixels on the left of your view (in this case a generic NSView).

So a constrain got added bonding the view's left edge directly to its superview. (Since the right edge is unconstrained it'll flop around in the breeze, just like the autoresizing mask says.)