From c0fcdd9c6196f1be94fe243f688e62611228d4bf Mon Sep 17 00:00:00 2001
From: hrsh7th <hrsh7th@gmail.com>
Date: Tue, 24 Aug 2021 22:43:02 +0900
Subject: [PATCH] Improve API stability

---
 README.md              | 108 +++++++++++++++++------------------------
 lua/cmp/core.lua       |   5 +-
 lua/cmp/init.lua       |  63 ++++++++++++++++++++++++
 lua/cmp/mapping.lua    |  96 ++++++++++++++++--------------------
 lua/cmp/utils/misc.lua |  12 +++++
 5 files changed, 165 insertions(+), 119 deletions(-)

diff --git a/README.md b/README.md
index b224465..7ff0473 100644
--- a/README.md
+++ b/README.md
@@ -1,6 +1,6 @@
 # nvim-cmp
 
-A completion plugin for neovim written in Lua.
+A completion plugin for neovim coded by Lua.
 
 
 Status
@@ -9,11 +9,11 @@ Status
 not yet stable but ok to use (for testing).
 
 
-Features
+Concept
 ====================
 
 - Support pairs-wise plugin automatically
-- Fully customizable via Lua functions (WIP)
+- Fully customizable via Lua functions
 - Fully supported LSP's Completion capabilities
   - Snippets
   - CommitCharacters
@@ -29,7 +29,7 @@ Features
 Setup
 ====================
 
-First, You should install core and sources by your favorite plugin manager.
+First, You should install nvim-cmp itself and completion sources by your favorite plugin manager.
 
 The `nvim-cmp` sources can be found in [here](https://github.com/topics/nvim-cmp).
 
@@ -46,20 +46,19 @@ Then setup configuration.
 lua <<EOF
   local cmp = require('cmp')
   cmp.setup {
-    -- You should change this example to your chosen snippet engine.
     snippet = {
       expand = function(args)
-        -- You must install `vim-vsnip` if you set up as same as the following.
+        -- You must install `vim-vsnip` if you use the following as-is.
         vim.fn['vsnip#anonymous'](args.body)
       end
     },
 
-    -- You must set mapping.
+    -- You must set mapping if you want.
     mapping = {
-      ['<C-p>'] = cmp.mapping.prev_item(),
-      ['<C-n>'] = cmp.mapping.next_item(),
-      ['<C-d>'] = cmp.mapping.scroll(-4),
-      ['<C-f>'] = cmp.mapping.scroll(4),
+      ['<C-p>'] = cmp.mapping.select_prev_item(),
+      ['<C-n>'] = cmp.mapping.select_next_item(),
+      ['<C-d>'] = cmp.mapping.scroll_docs(-4),
+      ['<C-f>'] = cmp.mapping.scroll_docs(4),
       ['<C-Space>'] = cmp.mapping.complete(),
       ['<C-e>'] = cmp.mapping.close(),
       ['<CR>'] = cmp.mapping.confirm({
@@ -70,7 +69,7 @@ lua <<EOF
 
     -- You should specify your *installed* sources.
     sources = {
-      { name = 'buffer' }
+      { name = 'buffer' },
     },
   }
 EOF
@@ -78,6 +77,7 @@ EOF
 " Setup buffer configuration (nvim-lua source only enables in Lua filetype).
 autocmd FileType lua lua require'cmp'.setup.buffer {
 \   sources = {
+      { name = 'buffer' },
 \     { name = 'nvim_lua' },
 \   },
 \ }
@@ -90,79 +90,61 @@ Configuration
 The default configuration can be found in [here](./lua/cmp/config/default.lua)
 
 You can use your own configuration like this:
+
 ```lua
 local cmp = require'cmp'
 cmp.setup {
   ...
   completion = {
-    autocomplete = { .. },
-    completeopt = 'menu,menuone,noselect',
-    keyword_pattern = [[\%(-\?\d\+\%(\.\d\+\)\?\|\h\w*\%(-\w*\)*\)]],
-    keyword_length = 1,
+    autocomplete = { ... },
   },
   sorting = {
     priority_weight = 2.,
     comparators = { ... },
   },
   mapping = {
-    ['<C-p>'] = cmp.mapping.prev_item(),
-    ['<C-n>'] = cmp.mapping.next_item(),
-    ['<C-d>'] = cmp.mapping.scroll(-4),
-    ['<C-f>'] = cmp.mapping.scroll(4),
-    ['<C-Space>'] = cmp.mapping.complete(),
-    ['<C-e>'] = cmp.mapping.close(),
-    ['<CR>'] = cmp.mapping.confirm({
-      behavior = cmp.ConfirmBehavior.Replace,
-      select = true,
-    })
+    ...
   },
   sources = { ... },
   ...
 }
 ```
 
-### mapping (type: table<string, fun(core: cmp.Core, fallback: function)>)
-
-_TODO: This API is not stable yet. It can be changed with no announcement._
+### mapping (type: table<string, fun(fallback: function)>)
 
 Define mappings with `cmp.mapping` helper.
 
-The `cmp.mapping` helper has the below functions.
-
-- *cmp.mapping.confirm({ select = true or false, behavior = cmp.ConfirmBehavior.Insert or cmp.ConfirmBehavior.Replace })*
-- *cmp.mapping.complete()*
-- *cmp.mapping.close()*
-- *cmp.mapping.next_item()*
-- *cmp.mapping.prev_item()*
-- *cmp.mapping.scroll(delta = number)*
-
-You can use `<Tab>`and `<S-Tab>` for navigating menu.
+You can use the following functions as mapping configuration like this.
 
 ```lua
--- This is just an example of LusSnip integration. You have to adjust it yourself.
-local luasnip = require'luasnip'
-local cmp = require'cmp'
-cmp.setup {
-  mapping = {
-    ['<Tab>'] = cmp.mapping.mode({ 'i', 's' }, function(_, fallback)
-      if vim.fn.pumvisible() == 1 then
-        vim.fn.feedkeys(vim.api.nvim_replace_termcodes('<C-n>', true, true, true), 'n')
-      elseif luasnip.expand_or_jumpable() then
-        vim.fn.feedkeys(vim.api.nvim_replace_termcodes('<Plug>luasnip-expand-or-jump', true, true, true), '')
-      else
-        fallback()
-      end
-    end),
-    ['<S-Tab>'] = cmp.mapping.mode({ 'i', 's' }, function(_, fallback)
-      if vim.fn.pumvisible() == 1 then
-        vim.fn.feedkeys(vim.api.nvim_replace_termcodes('<C-p>', true, true, true), 'n')
-      elseif luasnip.jumpable(-1) then
-        vim.fn.feedkeys(vim.api.nvim_replace_termcodes('<Plug>luasnip-jump-prev', true, true, true), '')
-      else
-        fallback()
-      end
-    end)
-  }
+mapping = {
+  ['<C-p>'] = cmp.mapping.select_prev_item(),
+  ['<C-n>'] = cmp.mapping.select_next_item(),
+  ['<C-d>'] = cmp.mapping.scroll_docs(-4),
+  ['<C-f>'] = cmp.mapping.scroll_docs(4),
+  ['<C-Space>'] = cmp.mapping.complete(),
+  ['<C-e>'] = cmp.mapping.close(),
+  ['<CR>'] = cmp.mapping.confirm({
+    behavior = cmp.ConfirmBehavior.Replace,
+    select = true,
+  })
+}
+```
+
+- *cmp.mapping.select_prev_item()*
+- *cmp.mapping.select_next_item()*
+- *cmp.mapping.scroll_docs(number)*
+- *cmp.mapping.complete()*
+- *cmp.mapping.close()*
+- *cmp.mapping.confirm({ select = bool, behavior = cmp.ConfirmBehavior.{Insert,Replace} })*
+
+In addition, You can specify vim's mode to those mapping functions like this.
+
+```lua
+mapping = {
+  ...
+  ['<Tab>'] = cmp.mapping(cmp.mapping.select_next_item(), { 'i', 's' })
+  ...
 }
 ```
 
diff --git a/lua/cmp/core.lua b/lua/cmp/core.lua
index e5d2b10..505dc25 100644
--- a/lua/cmp/core.lua
+++ b/lua/cmp/core.lua
@@ -75,10 +75,11 @@ core.on_keymap = function(keys, fallback)
   for key, action in pairs(config.get().mapping) do
     if key == keys then
       if type(action) == 'function' then
-        return action(core, fallback)
+        action(fallback)
       else
-        return action.invoke(core, fallback)
+        action.invoke(fallback)
       end
+      return
     end
   end
 
diff --git a/lua/cmp/init.lua b/lua/cmp/init.lua
index 103a2c0..c028f8b 100644
--- a/lua/cmp/init.lua
+++ b/lua/cmp/init.lua
@@ -1,4 +1,5 @@
 local core = require('cmp.core')
+local keymap = require('cmp.utils.keymap')
 local source = require('cmp.source')
 local config = require('cmp.config')
 local autocmd = require('cmp.autocmd')
@@ -31,6 +32,68 @@ cmp.unregister_source = function(id)
   core.unregister_source(id)
 end
 
+---Invoke completion manually
+cmp.complete = function()
+  core.complete(core.get_context({ reason = cmp.ContextReason.Manual }))
+  return true
+end
+
+---Close current completion
+cmp.close = function()
+  if vim.fn.pumvisible() == 1 then
+    core.reset()
+    return true
+  else
+    return false
+  end
+end
+
+---Select next item if possible
+cmp.select_next_item = function()
+  if vim.fn.pumvisible() == 1 then
+    vim.fn.feedkeys(keymap.t('<C-n>'), 'n')
+    return true
+  else
+    return false
+  end
+end
+
+---Select prev item if possible
+cmp.select_prev_item = function()
+  if vim.fn.pumvisible() == 1 then
+    vim.fn.feedkeys(keymap.t('<C-p>'), 'n')
+    return true
+  else
+    return false
+  end
+end
+
+---Scrolling documentation window if possible
+cmp.scroll_docs = function(delta)
+  if core.menu.float:is_visible() then
+    core.menu.float:scroll(delta)
+    return true
+  else
+    return false
+  end
+end
+
+---Confirm completion
+cmp.confirm = function(option)
+  option = option or {}
+  local e = core.menu:get_selected_entry() or (option.select and core.menu:get_first_entry() or nil)
+  if e then
+    core.confirm(e, {
+      behavior = option.behavior,
+    }, function()
+      core.complete(core.get_context({ reason = cmp.ContextReason.TriggerOnly }))
+    end)
+    return true
+  else
+    return false
+  end
+end
+
 ---@type cmp.Setup
 cmp.setup = setmetatable({
   global = function(c)
diff --git a/lua/cmp/mapping.lua b/lua/cmp/mapping.lua
index acefac8..a9660fa 100644
--- a/lua/cmp/mapping.lua
+++ b/lua/cmp/mapping.lua
@@ -1,82 +1,70 @@
-local types = require('cmp.types')
+local misc = require('cmp.utils.misc')
 
-local mapping = {}
-
-mapping.mode = function(modes, action_or_invoke)
-  local invoke = action_or_invoke
-  if type(action_or_invoke) == 'table' then
-    if type(action_or_invoke.invoke) == 'function' then
-      invoke = action_or_invoke.invoke
-    else
-      error('`invoke` must be function or result of `cmp.mapping.mode`.')
+local mapping = setmetatable({}, {
+  __call = function(_, invoke, modes)
+    return {
+      invoke = function(...)
+        invoke(...)
+      end,
+      modes = modes or { 'i' },
+    }
+  end,
+})
+---Invoke completion
+mapping.complete = function()
+  return function(fallback)
+    if not require('cmp').complete() then
+      fallback()
     end
   end
-  return {
-    modes = modes,
-    invoke = invoke,
-  }
-end
-
-mapping.complete = function()
-  return mapping.mode({ 'i' }, function(core)
-    core.complete(core.get_context({ reason = types.cmp.ContextReason.Manual }))
-  end)
 end
 
+---Close current completion menu if it displayed.
 mapping.close = function()
-  return mapping.mode({ 'i' }, function(core, fallback)
-    if vim.fn.pumvisible() == 1 then
-      core.reset()
-    else
+  return function(fallback)
+    if not require('cmp').close() then
       fallback()
     end
-  end)
+  end
 end
 
-mapping.scroll = function(delta)
-  return mapping.mode({ 'i' }, function(core, fallback)
-    if core.menu.float:is_visible() then
-      core.menu.float:scroll(delta)
-    else
+---Scroll documentation window.
+mapping.scroll_docs = function(delta)
+  return function(fallback)
+    if not require('cmp').scroll_docs(delta) then
       fallback()
     end
-  end)
+  end
 end
+mapping.scroll = misc.deprecated(mapping.scroll_docs, '`cmp.mapping.scroll` is deprecated. Please change it to `cmp.mapping.scroll_docs` instead.')
 
-mapping.next_item = function()
-  return mapping.mode({ 'i' }, function(_, fallback)
-    if vim.fn.pumvisible() == 1 then
-      vim.fn.feedkeys(vim.api.nvim_replace_termcodes('<C-n>', true, true, true), 'n')
-    else
+---Select next completion item.
+mapping.select_next_item = function()
+  return function(fallback)
+    if not require('cmp').select_next_item() then
       fallback()
     end
-  end)
+  end
 end
+mapping.next_item = misc.deprecated(mapping.select_next_item, '`cmp.mapping.next_item` is deprecated. Please change it to `cmp.mapping.select_next_item` instead.')
 
-mapping.prev_item = function()
-  return mapping.mode({ 'i' }, function(_, fallback)
-    if vim.fn.pumvisible() == 1 then
-      vim.fn.feedkeys(vim.api.nvim_replace_termcodes('<C-p>', true, true, true), 'n')
-    else
+---Select prev completion item.
+mapping.select_prev_item = function()
+  return function(fallback)
+    if not require('cmp').select_prev_item() then
       fallback()
     end
-  end)
+  end
 end
+mapping.prev_item = misc.deprecated(mapping.select_prev_item, '`cmp.mapping.prev_item` is deprecated. Please change it to `cmp.mapping.select_prev_item` instead.')
 
+---Confirm selection
 mapping.confirm = function(option)
-  option = option or {}
-  return mapping.mode({ 'i' }, function(core, fallback)
-    local e = core.menu:get_selected_entry() or (option.select and core.menu:get_first_entry() or nil)
-    if e then
-      core.confirm(e, {
-        behavior = option.behavior,
-      }, function()
-        core.complete(core.get_context({ reason = types.cmp.ContextReason.TriggerOnly }))
-      end)
-    else
+  return function(fallback)
+    if not require('cmp').confirm(option) then
       fallback()
     end
-  end)
+  end
 end
 
 return mapping
diff --git a/lua/cmp/utils/misc.lua b/lua/cmp/utils/misc.lua
index 147d588..a0f2773 100644
--- a/lua/cmp/utils/misc.lua
+++ b/lua/cmp/utils/misc.lua
@@ -136,4 +136,16 @@ misc.to_vimindex = function(text, utfindex)
   return utfindex + 1
 end
 
+---Mark the function as deprecated
+misc.deprecated = function(fn, msg)
+  local printed = false
+  return function(...)
+    if not printed then
+      print(msg)
+      printed = true
+    end
+    return fn(...)
+  end
+end
+
 return misc