3rdparties/software/alexandria-20200427-git/alexandria-1/features.lisp (717 bytes)
1 (in-package :alexandria) 2 3 (defun featurep (feature-expression) 4 "Returns T if the argument matches the state of the *FEATURES* 5 list and NIL if it does not. FEATURE-EXPRESSION can be any atom 6 or list acceptable to the reader macros #+ and #-." 7 (etypecase feature-expression 8 (symbol (not (null (member feature-expression *features*)))) 9 (cons (check-type (first feature-expression) symbol) 10 (eswitch ((first feature-expression) :test 'string=) 11 (:and (every #'featurep (rest feature-expression))) 12 (:or (some #'featurep (rest feature-expression))) 13 (:not (assert (= 2 (length feature-expression))) 14 (not (featurep (second feature-expression))))))))