From c9ce8ac4d11dab5d53fd1b15bc06e004fc89b500 Mon Sep 17 00:00:00 2001
From: Ade Attwood <ade@practically.io>
Date: Sun, 24 Jul 2022 12:50:30 +0100
Subject: [PATCH] feat: implement emacs bindings for the prompt like bash

Now the prompt will act like the default bash readline with emacs key
bindings, clear and delete word.

You can now also move left and right in the prompt to insert chars in
the middle of the prompt rather than having to delete your search term
and start again.
---
 lua/ivy/prompt.lua | 27 +++++++++++++++++++++++++--
 lua/ivy/window.lua |  5 ++++-
 2 files changed, 29 insertions(+), 3 deletions(-)

diff --git a/lua/ivy/prompt.lua b/lua/ivy/prompt.lua
index 264cc1b..f867d2e 100644
--- a/lua/ivy/prompt.lua
+++ b/lua/ivy/prompt.lua
@@ -3,18 +3,39 @@ local prompt_prefix = ">> "
 
 local prompt = {}
 
+prompt.suffix = ""
 prompt.value = ""
 
 prompt.text = function()
-  return prompt.value
+  return prompt.value .. prompt.suffix
 end
 prompt.update = function()
-  vim.notify(prompt_prefix .. prompt.text())
+  vim.api.nvim_echo({
+    { prompt_prefix, "None" },
+    { prompt.value:sub(1, -2), "None" },
+    { prompt.value:sub(-1, -1), "Underlined" },
+    { prompt.suffix, "None" },
+  }, false, {})
 end
 
 prompt.input = function(char)
   if char == "BACKSPACE" then
     prompt.value = string.sub(prompt.value, 0, -2)
+  elseif char == "LEFT" then
+    if #prompt.value > 0 then
+      prompt.suffix = prompt.value:sub(-1, -1) .. prompt.suffix
+      prompt.value = prompt.value:sub(1, -2)
+    end
+  elseif char == "RIGHT" then
+    if #prompt.suffix > 0 then
+      prompt.value = prompt.value .. prompt.suffix:sub(1, 1)
+      prompt.suffix = prompt.suffix:sub(2, -1)
+    end
+  elseif char == "DELETE_WORD" then
+    prompt.value = prompt.value:match "(.*)%s+.*$"
+    if prompt.value == nil then
+      prompt.value = ""
+    end
   elseif char == "\\\\" then
     prompt.value = prompt.value .. "\\"
   else
@@ -26,11 +47,13 @@ end
 
 prompt.set = function(value)
   prompt.value = value
+  prompt.suffix = ""
   prompt.update()
 end
 
 prompt.destroy = function()
   prompt.value = ""
+  prompt.suffix = ""
   vim.notify ""
 end
 
diff --git a/lua/ivy/window.lua b/lua/ivy/window.lua
index 7b14308..ee2f23d 100644
--- a/lua/ivy/window.lua
+++ b/lua/ivy/window.lua
@@ -72,7 +72,7 @@ window.make_buffer = function()
   end
 
   vim.api.nvim_buf_set_keymap(window.buffer, "n", "<C-c>", "<cmd>lua vim.ivy.destroy()<CR>", opts)
-  vim.api.nvim_buf_set_keymap(window.buffer, "n", "<C-w>", "<cmd>lua vim.ivy.search('')<CR>", opts)
+  vim.api.nvim_buf_set_keymap(window.buffer, "n", "<C-u>", "<cmd>lua vim.ivy.search('')<CR>", opts)
   vim.api.nvim_buf_set_keymap(window.buffer, "n", "<C-n>", "<cmd>lua vim.ivy.next()<CR>", opts)
   vim.api.nvim_buf_set_keymap(window.buffer, "n", "<C-p>", "<cmd>lua vim.ivy.previous()<CR>", opts)
   vim.api.nvim_buf_set_keymap(window.buffer, "n", "<C-M-n>", "<cmd>lua vim.ivy.next(); vim.ivy.checkpoint()<CR>", opts)
@@ -85,6 +85,9 @@ window.make_buffer = function()
   )
   vim.api.nvim_buf_set_keymap(window.buffer, "n", "<CR>", "<cmd>lua vim.ivy.complete()<CR>", opts)
   vim.api.nvim_buf_set_keymap(window.buffer, "n", "<BS>", "<cmd>lua vim.ivy.input('BACKSPACE')<CR>", opts)
+  vim.api.nvim_buf_set_keymap(window.buffer, "n", "<Left>", "<cmd>lua vim.ivy.input('LEFT')<CR>", opts)
+  vim.api.nvim_buf_set_keymap(window.buffer, "n", "<Right>", "<cmd>lua vim.ivy.input('RIGHT')<CR>", opts)
+  vim.api.nvim_buf_set_keymap(window.buffer, "n", "<C-w>", "<cmd>lua vim.ivy.input('DELETE_WORD')<CR>", opts)
 end
 
 window.get_current_selection = function()