From a2016241df9cb4d35c03db5b24f08ec0cc8ca7e8 Mon Sep 17 00:00:00 2001
From: Evgeny Poberezkin <2769109+epoberezkin@users.noreply.github.com>
Date: Sat, 10 Apr 2021 12:53:22 +0100
Subject: [PATCH] support Home, End and Del keys (#87)

* add Home and End keys

* support Delete key

* simplify updateTermState
---
 apps/dog-food/ChatTerminal/Core.hs | 13 +++++++++----
 1 file changed, 9 insertions(+), 4 deletions(-)

diff --git a/apps/dog-food/ChatTerminal/Core.hs b/apps/dog-food/ChatTerminal/Core.hs
index 24856e498..09d919795 100644
--- a/apps/dog-food/ChatTerminal/Core.hs
+++ b/apps/dog-food/ChatTerminal/Core.hs
@@ -51,6 +51,9 @@ updateTermState ac tw (key, ms) ts@TerminalState {inputString = s, inputPosition
     | otherwise -> ts
   TabKey -> insertCharsWithContact "    "
   BackspaceKey -> backDeleteChar
+  DeleteKey -> deleteChar
+  HomeKey -> setPosition 0
+  EndKey -> setPosition $ length s
   ArrowKey d -> case d of
     Leftwards
       | ms == mempty -> setPosition $ max 0 (p - 1)
@@ -85,10 +88,12 @@ updateTermState ac tw (key, ms) ts@TerminalState {inputString = s, inputPosition
       Nothing -> ""
     backDeleteChar
       | p == 0 || null s = ts
-      | p >= length s = ts' backDeleteLast
-      | otherwise = ts' backDelete
-    backDeleteLast = if null s then (s, 0) else let s' = init s in (s', length s')
-    backDelete = let (b, a) = splitAt p s in (init b <> a, p - 1)
+      | p >= length s = ts' (init s, length s - 1)
+      | otherwise = let (b, a) = splitAt p s in ts' (init b <> a, p - 1)
+    deleteChar
+      | p >= length s || null s = ts
+      | p == 0 = ts' (tail s, 0)
+      | otherwise = let (b, a) = splitAt p s in ts' (b <> tail a, p)
     setPosition p' = ts' (s, p')
     prevWordPos
       | p == 0 || null s = p