From 7e13bb4e5f142d2fbfaa03f88ba1263978adc930 Mon Sep 17 00:00:00 2001
From: Matthew Egan Odendahl <gilch@users.noreply.github.com>
Date: Fri, 15 Apr 2016 20:33:42 -0600
Subject: [PATCH] add as-> macro

---
 hy/core/macros.hy | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/hy/core/macros.hy b/hy/core/macros.hy
index d39aabe..dc3c316 100644
--- a/hy/core/macros.hy
+++ b/hy/core/macros.hy
@@ -30,6 +30,15 @@
         [hy.models.symbol [HySymbol]]
         [hy._compat [PY33 PY34]])
 
+(defmacro as-> [head name &rest rest]
+  "Becomes ordered assignments to the provided name. The previous result
+  is thus available in each form. Returns the final result, and leaves the name
+  bound to it in the local scope. This behaves like the threading macros, but
+  requires you to specify the threading point per form via the name."
+  `(do (setv
+         ~name ~head
+         ~@(interleave (repeat name) rest))
+     ~name))
 
 (defmacro with [args &rest body]
   "shorthand for nested with* loops: