From: Doug Coleman <doug.coleman@gmail.com>
Date: Sun, 20 Feb 2022 01:28:13 +0000 (-0600)
Subject: assocs.extras: Add collect-key-by and collect-value-by
X-Git-Tag: 0.99~1498
X-Git-Url: https://gitweb.factorcode.org/gitweb.cgi?p=factor.git;a=commitdiff_plain;h=bc3f412e1b6e1fa5c1f76dca5d286be994b1ae94

assocs.extras: Add collect-key-by and collect-value-by
---

diff --git a/extra/assocs/extras/extras.factor b/extra/assocs/extras/extras.factor
index addd66b5fd..9a6ba7553e 100644
--- a/extra/assocs/extras/extras.factor
+++ b/extra/assocs/extras/extras.factor
@@ -222,3 +222,11 @@ PRIVATE>
 
 : counts ( seq elts -- counts )
     [ histogram ] dip intersect-keys ;
+
+: collect-key-by ( ... seq quot: ( ... obj -- ... key ) -- ... assoc )
+    [ keep swap ] curry H{ } clone
+    [ '[ @ [ first ] dip _ push-at ] each ] keep ; inline
+
+: collect-value-by ( ... seq quot: ( ... obj -- ... key ) -- ... assoc )
+    [ keep swap ] curry H{ } clone
+    [ '[ @ [ second ] dip _ push-at ] each ] keep ; inline