From 9dc71445eb2bd470279ab135b0678aa2c2b815b5 Mon Sep 17 00:00:00 2001
From: kusumotonorio <47816570+kusumotonorio@users.noreply.github.com>
Date: Sat, 15 Feb 2020 22:04:08 +0900
Subject: [PATCH] Supports dotted pair notation

---
 basis/lists/lists.factor                 | 21 ++++++++++++++++++++-
 basis/prettyprint/backend/backend.factor |  7 ++++++-
 2 files changed, 26 insertions(+), 2 deletions(-)

diff --git a/basis/lists/lists.factor b/basis/lists/lists.factor
index 206752f7ca..fe7fa2f608 100644
--- a/basis/lists/lists.factor
+++ b/basis/lists/lists.factor
@@ -105,4 +105,23 @@ M: list >list ;
 
 M: sequence >list sequence>list ;
 
-SYNTAX: L{ \ } [ sequence>list ] parse-literal ;
\ No newline at end of file
+: items>list ( seq -- cons-pair )
+    dup empty? [ drop +nil+ ] [
+        reverse unclip swap [ swap cons ] each
+    ] if ;
+
+:: (parse-list-literal) ( accum right-of-dot? -- accum )
+    accum scan-token {
+        { "}" [ +nil+ , ] }
+        { "rest:" [ t (parse-list-literal) ] }
+        [
+            parse-datum dup parsing-word? [
+                V{ } clone swap execute-parsing first
+            ] when
+            , right-of-dot? [ "}" expect ] [ f (parse-list-literal) ] if ]
+    } case ;
+
+: parse-list-literal ( accum -- accum object )
+    [ f (parse-list-literal) ] { } make items>list ;
+
+SYNTAX: L{ parse-list-literal suffix! ;
diff --git a/basis/prettyprint/backend/backend.factor b/basis/prettyprint/backend/backend.factor
index cd3d388205..28d4d96b8c 100644
--- a/basis/prettyprint/backend/backend.factor
+++ b/basis/prettyprint/backend/backend.factor
@@ -277,7 +277,12 @@ M: cons-state pprint*
                 '[ dup cons-state? _ length _ < and ]
                 [ uncons swap , ] while
             ] { } make
-            [ pprint* ] each nil? [ "~more~" text ] unless
+            [ pprint* ] each
+            dup list? [
+                nil? [ "~more~" text ] unless
+            ] [
+                "." text pprint*
+            ] if
             block>
         ] dip pprint-word block>
     ] check-recursion ;