Add: (-let) Bind vars to EIEIO object slots with &obj

Fixes #250.

README.md

@@ -2321,6 +2321,10 @@ Key/value stores:
                                   `source` hash table to aK.  If the
                                   value is not found, aK is nil.
 
+    (&obj key0 a0 ... keyN aN) - bind value mapped by keyK in the
+                                 `source` `eieio` object to aK.  If the
+                                 value is not found, aK is nil.
+
 Further, special keyword &keys supports "inline" matching of
 plist-like key-value pairs, similarly to &keys keyword of
 `cl-defun`.

dash.el

@@ -1738,7 +1738,9 @@ Valid values are &plist, &alist and &hash."
                                    ((eq type '&alist)
                                     `(cdr (assoc ,k ,source)))
                                    ((eq type '&hash)
-                                    `(gethash ,k ,source)))))
+                                    `(gethash ,k ,source))
+                                   ((eq type '&obj)
+                                    `(oref ,source ,k)))))
                      (cond
                       ((symbolp v)
                        (list (list v getter)))
@@ -1771,7 +1773,7 @@ Key-value stores are disambiguated by placing a token &plist,
       (let ((s (car match-form)))
         (cons (list s source)
               (dash--match (cddr match-form) s))))
-     ((memq (car match-form) '(&keys &plist &alist &hash))
+     ((memq (car match-form) '(&keys &plist &alist &hash &obj))
       (dash--match-kv match-form source))
      (t (dash--match-cons match-form source))))
    ((vectorp match-form)
@@ -1883,6 +1885,10 @@ Key/value stores:
                                 SOURCE hash table to aK.  If the
                                 value is not found, aK is nil.
 
+  (&obj key0 a0 ... keyN aN) - bind value mapped by keyK in the
+                               SOURCE EIEIO object to aK.  If the
+                               value is not found, aK is nil.
+
 Further, special keyword &keys supports \"inline\" matching of
 plist-like key-value pairs, similarly to &keys keyword of
 `cl-defun'.

dash.info

@@ -2135,6 +2135,9 @@ control.
      (&hash key0 a0 ...  keyN aN) - bind value mapped by keyK in the
      SOURCE hash table to aK. If the value is not found, aK is nil.
 
+     (&obj key0 a0 ...  keyN aN) - bind value mapped by keyK in the
+     SOURCE EIEIO object to aK. If the value is not found, aK is nil.
+
      Further, special keyword &keys supports "inline" matching of
      plist-like key-value pairs, similarly to &keys keyword of
      ‘cl-defun’.

dash.texi

@@ -3553,6 +3553,10 @@ Key/value stores:
                                   @var{source} hash table to aK.  If the
                                   value is not found, aK is nil.
 
+    (&obj key0 a0 ... keyN aN) - bind value mapped by keyK in the
+                                 @var{source} @var{eieio} object to aK.  If the
+                                 value is not found, aK is nil.
+
 Further, special keyword &keys supports "inline" matching of
 plist-like key-value pairs, similarly to &keys keyword of
 @code{cl-defun}.

dev/examples.el

@@ -23,6 +23,7 @@
 ;;; Code:
 
 (require 'dash)
+(require 'eieio)
 
 (defun even? (num) (= 0 (% num 2)))
 (defun square (num) (* num num))
@@ -1109,7 +1110,13 @@ new list."
     (-let [(list &as _ _ _ a _ _ _ b _ _ _ c) (list 1 2 3 4 5 6 7 8 9 10 11 12)] (list a b c list)) => '(4 8 12 (1 2 3 4 5 6 7 8 9 10 11 12))
     (-let (((x &as a b) (list 1 2))
            ((y &as c d) (list 3 4)))
-      (list a b c d x y)) => '(1 2 3 4 (1 2) (3 4)))
+      (list a b c d x y)) => '(1 2 3 4 (1 2) (3 4))
+      (-let (((&obj :slot1 one :slot2 two) (progn
+                                             (defclass -let-test-class ()
+                                               ((slot1 :initarg :slot1)
+                                                (slot2 :initarg :slot2)))
+                                             (make-instance '-let-test-class :slot1 1 :slot2 2))))
+        (list one two)) => '(1 2))
 
   (defexamples -let*
     (-let* (((a . b) (cons 1 2))