[elpa] externals/dash 8f9fc41 340/439: Add support for multiple input arguments to -lambda

[Phillip Lord]

branch: externals/dash
commit 8f9fc4113d90b8f48192b56ea6d60db1bce2dc87
Author: Matus Goljer <address@hidden>
Commit: Matus Goljer <address@hidden>

    Add support for multiple input arguments to -lambda
---
 README.md       |    2 +-
 dash.el         |    8 ++++++--
 dev/examples.el |    2 ++
 3 files changed, 9 insertions(+), 3 deletions(-)

diff --git a/README.md b/README.md
index a065eec..5b425ac 100644
--- a/README.md
+++ b/README.md
@@ -1822,7 +1822,7 @@ See `-let` for the description of destructuring mechanism.
 ```cl
 (-map (-lambda ((x y)) (+ x y)) '((1 2) (3 4) (5 6))) ;; => '(3 7 11)
 (-map (-lambda ([x y]) (+ x y)) '([1 2] [3 4] [5 6])) ;; => '(3 7 11)
-(-map (-lambda ((&plist :a a :b b)) (+ a b)) '((:a 1 :b 2) (:a 3 :b 4) (:a 5 
:b 6))) ;; => '(3 7 11)
+(funcall (-lambda ((_ . a) (_ . b)) (-concat a b)) '(1 2 3) '(4 5 6)) ;; => 
'(2 3 5 6)
 ```
 
 
diff --git a/dash.el b/dash.el
index 9b32668..7efe2b7 100644
--- a/dash.el
+++ b/dash.el
@@ -1426,8 +1426,12 @@ See `-let' for the description of destructuring 
mechanism."
          (symbolp (car match-form)))
     `(lambda ,match-form ,@body))
    (t
-    `(lambda (x)
-       (-let* ((,@match-form x)) ,@body)))))
+    (let* ((inputs (--map-indexed (list it (make-symbol (format "input%d" 
it-index))) match-form)))
+      ;; TODO: because inputs to the lambda are evaluated only once,
+      ;; -let* need not to create the extra bindings to ensure that.
+      ;; We should find a way to optimize that.  Not critical however.
+      `(lambda ,(--map (cadr it) inputs)
+         (-let* ,inputs ,@body))))))
 
 (defun -distinct (list)
   "Return a new list with all duplicates removed.
diff --git a/dev/examples.el b/dev/examples.el
index 2bd0ee1..d78bccc 100644
--- a/dev/examples.el
+++ b/dev/examples.el
@@ -757,8 +757,10 @@ new list."
   (defexamples -lambda
     (-map (-lambda ((x y)) (+ x y)) '((1 2) (3 4) (5 6))) => '(3 7 11)
     (-map (-lambda ([x y]) (+ x y)) '([1 2] [3 4] [5 6])) => '(3 7 11)
+    (funcall (-lambda ((_ . a) (_ . b)) (-concat a b)) '(1 2 3) '(4 5 6)) => 
'(2 3 5 6)
     (-map (-lambda ((&plist :a a :b b)) (+ a b)) '((:a 1 :b 2) (:a 3 :b 4) (:a 
5 :b 6))) => '(3 7 11)
     (-map (-lambda (x) (let ((k (car x)) (v (cadr x))) (+ k v))) '((1 2) (3 4) 
(5 6))) => '(3 7 11)
+    (funcall (-lambda ((a) (b)) (+ a b)) '(1 2 3) '(4 5 6)) => 5
     (condition-case nil (progn (-lambda a t) (error "previous form should 
error")) (error t)) => t))
 
 (def-example-group "Side-effects"