To date, it supports:
- let*
- destructuring-bind (with "don't care" variable _)
- multiple-value-bind (with "don't care" variable _)
- with-slots
- "projection" of slot values of structure/object to normal values, avoiding slot lookup every time the slot value is used in the scope of let*
- binding of a group of variables to one initialization value
Other binders can be added trivially with define-binder macro (see let-star.lisp).
X.LET-STAR shadows let* (since it's completely compatible with common-lisp:let*) To use the X.LET-STAR library, your defpackage should roughly look as:
(defpackage :your-lib (:use :common-lisp :x.let-star ...) (:shadowing-import-from x.let-star let*) ;; the important line ...)
example:
(defstruct xxx a b c)
(let* (((_ (e . _) &key (g :xxx)) '(:sdfg (:wert :dfg :tyu) :g 100)) ;; b
((:mval h _) (rem 1234 34)) ;; c
((:slot a (b-first b)) (make-xxx :a 123)) ;; d
((:slotval (b-second b) c) (make-xxx :b 3245 :c 3456)) ;; e
((:all x y z) :init)) ;; f
(values e g h a b-first b-second c x y z))
expands to:
(DESTRUCTURING-BIND ;; b
(#:IGNORE-1021 (E . #:IGNORE-1022) &KEY (G :XXX)) ;; b
'(:SDFG (:WERT :DFG :TYU) :G 100) ;; b
(DECLARE (IGNORE #:IGNORE-1021) (IGNORE #:IGNORE-1022)) ;; b
(MULTIPLE-VALUE-BIND ;; c
(H #:IGNORE-1020) ;; c
(REM 1234 34) ;; c
(DECLARE (IGNORE #:IGNORE-1020)) ;; c
(WITH-SLOTS (A (B-FIRST B)) (MAKE-XXX :A 123) ;; d
(LET ((#:VAL1019 (MAKE-XXX :B 3245 :C 3456))) ;; e
(LET ((B-SECOND (SLOT-VALUE #:VAL1019 'B))) ;; e
(LET ((C (SLOT-VALUE #:VAL1019 'C))) ;; e
(LET ((#:VAL1139 :INIT)) ;; f
(LET ((X #:VAL1139) (Y #:VAL1139) (Z #:VAL1139)) ;; f
(VALUES E G H A B-FIRST B-SECOND C X Y Z)))))))))
You can checkout the sources directly as well: X.LET-STAR
License: BSD