From 45e7fd792191a8872595e13e523ffae7071e627b Mon Sep 17 00:00:00 2001
From: Doug Coleman <doug.coleman@gmail.com>
Date: Sat, 8 Nov 2014 18:26:21 -0800
Subject: [PATCH] assocs: Make the output from zip, zip-index, and map-index
 the same type as the first seq/assoc argument. Add tests.

---
 core/assocs/assocs-tests.factor | 12 ++++++++++++
 core/assocs/assocs.factor       |  6 +++---
 2 files changed, 15 insertions(+), 3 deletions(-)

diff --git a/core/assocs/assocs-tests.factor b/core/assocs/assocs-tests.factor
index da1deb0d8a..dc036799b4 100644
--- a/core/assocs/assocs-tests.factor
+++ b/core/assocs/assocs-tests.factor
@@ -218,6 +218,10 @@ unit-test
     { 11 23 35 }
 } [ { 11 22 33 } [ + ] map-index ] unit-test
 
+{
+    V{ 11 23 35 }
+} [ V{ 11 22 33 } [ + ] map-index ] unit-test
+
 {
     V{ 11 23 35 }
 } [ { 11 22 33 } [ + ] V{ } map-index-as ] unit-test
@@ -235,6 +239,10 @@ unit-test
     { { 1 4 } { 2 5 } { 3 6 } }
 } [ { 1 2 3 } { 4 5 6 } zip ] unit-test
 
+{
+    V{ { 1 4 } { 2 5 } { 3 6 } }
+} [ V{ 1 2 3 } { 4 5 6 } zip ] unit-test
+
 {
     { { 1 4 } { 2 5 } { 3 6 } }
 } [ { 1 2 3 } { 4 5 6 } { } zip-as ] unit-test
@@ -267,6 +275,10 @@ unit-test
     { { 11 0 } { 22 1 } { 33 2 } }
 } [ { 11 22 33 } zip-index ] unit-test
 
+{
+    V{ { 11 0 } { 22 1 } { 33 2 } }
+} [ V{ 11 22 33 } zip-index ] unit-test
+
 {
     { { 11 0 } { 22 1 } { 33 2 } }
 } [ { 11 22 33 } { } zip-index-as ] unit-test
diff --git a/core/assocs/assocs.factor b/core/assocs/assocs.factor
index cf458c0700..747c620d5e 100644
--- a/core/assocs/assocs.factor
+++ b/core/assocs/assocs.factor
@@ -207,7 +207,7 @@ M: assoc value-at* swap [ = nip ] curry assoc-find nip ;
     ] if ; inline
 
  : zip ( keys values -- alist )
-     { } zip-as ; inline
+     over zip-as ; inline
 
 : map-index-as ( ... seq quot: ( ... elt index -- ... newelt ) exemplar -- ... obj )
     dup sequence? [
@@ -219,13 +219,13 @@ M: assoc value-at* swap [ = nip ] curry assoc-find nip ;
     ] if ; inline
 
 : map-index ( ... seq quot: ( ... elt index -- ... newelt ) -- ... newseq )
-    { } map-index-as ; inline
+    over map-index-as ; inline
 
 : zip-index-as ( values exemplar -- obj )
     [ [ 2array ] ] dip map-index-as ; inline
 
 : zip-index ( values -- alist )
-    { } zip-index-as ; inline
+    dup zip-index-as ; inline
 
 : unzip ( assoc -- keys values )
     dup assoc-empty? [ drop { } { } ] [ >alist flip first2 ] if ;