plist-get

plist-get is a built-in function in `C source code'.

(plist-get PLIST PROP)

Extract a value from a property list.
PLIST is a property list, which is a list of the form
(PROP1 VALUE1 PROP2 VALUE2...). This function returns the value
corresponding to the given PROP, or nil if PROP is not one of the
properties on the list. This function never signals an error.