From dac3a40a2a06aa0b5dbe2d17b217b2d1007a707d Mon Sep 17 00:00:00 2001
From: Marshall Lochbaum <mwlochbaum@gmail.com>
Date: Thu, 31 Dec 2020 21:59:48 -0500
Subject: =?UTF-8?q?Use=20shaped=20identities=20for=20arithmetic=20Insert?=
 =?UTF-8?q?=20and=20support=20=E2=88=BE?=
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---
 src/r.bqn | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

(limited to 'src')

diff --git a/src/r.bqn b/src/r.bqn
index 6c3678ed..305d7447 100644
--- a/src/r.bqn
+++ b/src/r.bqn
@@ -394,7 +394,9 @@ _rankOp_←{
 }
 _insert←{
   "˝: 𝕩 must have rank at least 1" ! 1≤=𝕩
-  𝕨 𝔽´ <˘𝕩
+  F←𝔽
+  Id ← {s←1 Drop ≢𝕩 ⋄ s joinPrim˙⊸≠◶⟨(0<↕∘≠)⊸×⊸⥊⟜⟨⟩, Reshape⟜Identity⟩ f}
+  𝕨 (0<≠)⊘1◶Id‿{𝕨F´<˘𝕩} 𝕩
 }
 ˝ ← _insert
 
@@ -588,6 +590,7 @@ _repeat_←{
 }
 
 ReshapeT ← ⟨∘,⌊,⌽,↑⟩⊑∘⊐<
+JoinPrim ← ∾
 
 ⍟ ↩ _repeat_
 ⥊ ↩ Deshape        ⊘ Reshape
-- 
cgit v1.2.3