feat(copilot): Enable inline suggestion cycling

Author: Lucklyric

README.md

@@ -45,5 +45,4 @@ See `:help copilot` for more information.
 
 ## Limitations
 
-Copilot.vim does not yet support cycling through alternate suggestions on
-Alt+[ and Alt+], or opening the GitHub Copilot panel on Ctrl+Enter.
+Copilot.vim does not yet support opening the GitHub Copilot panel on Ctrl+Enter.

autoload/copilot.vim

@@ -2,13 +2,17 @@ if exists('g:autoloaded_copilot')
   finish
 endif
 let g:autoloaded_copilot = 1
+let g:copilot_echo_complettions = 1
 
 scriptencoding utf-8
 
 let s:has_ghost_text = has('nvim-0.6') && exists('*nvim_buf_get_mark')
 
 let s:hlgroup = 'CopilotSuggestion'
 
+let b:_current_copilot_suggestion_index = 0
+let b:_current_copilot_suggestions = {}
+
 if len($XDG_CONFIG_HOME)
   let s:config_root = $XDG_CONFIG_HOME
 elseif has('win32')
@@ -207,7 +211,7 @@ function! copilot#Complete(...) abort
   let doc = copilot#doc#Get()
   if !exists('g:_copilot_completion.params.doc') || g:_copilot_completion.params.doc !=# doc
     let g:_copilot_completion =
-          \ copilot#agent#Request('getCompletions', {'doc': doc, 'options': {}})
+          \ copilot#agent#Request('getCompletionsCycling', {'doc': doc, 'options': {}})
     let g:_copilot_last_completion = g:_copilot_completion
   endif
   let completion = g:_copilot_completion
@@ -337,14 +341,35 @@ endfunction
 
 function! s:HandleTriggerResult(result) abort
   if exists('a:result.completions')
+    if g:copilot_echo_complettions
+      echo 'copilot:' . len(a:result.completions) . ' completions'
+    endif
+    let b:_current_copilot_suggestions =  a:result.completions
+    let b:_current_copilot_suggestion_index = 0
     let b:_copilot_suggestion = get(a:result.completions, 0, {})
   else
     let b:_copilot_suggestion = {}
+    let b:_current_copilot_suggestion_index = 0
+    let b:_current_copilot_suggestions =  {}
   endif
   let b:_copilot_completion = b:_copilot_suggestion
   call s:UpdatePreview()
 endfunction
 
+function! copilot#NextResult(direction)
+  let index = b:_current_copilot_suggestion_index + a:direction
+  if index < 0
+    let b:_current_copilot_suggestion_index = len(b:_current_copilot_suggestions) - 1
+  elseif index >= len(b:_current_copilot_suggestions)
+    let b:_current_copilot_suggestion_index = 0
+  else
+    let b:_current_copilot_suggestion_index = index
+  endif
+  let b:_copilot_suggestion = get(b:_current_copilot_suggestions, b:_current_copilot_suggestion_index, {})
+  call s:UpdatePreview()
+  return ""
+endfunction
+
 function! s:Trigger(bufnr, timer) abort
   let timer = get(g:, '_copilot_timer', -1)
   unlet! g:_copilot_timer

doc/copilot.txt

@@ -78,6 +78,12 @@ Other Maps ~
                                                 *copilot-i_CTRL-]*
 <C-]>                   Dismiss the current suggestion.
 
+                                                *copilot-i_ALT-]*
+<A-]>                   Show next inline suggestion.
+
+                                                *copilot-i_ALT-[*
+<A-[>                   Show previous inline suggestion.
+
 SYNTAX HIGHLIGHTING                             *copilot-highlighting*
 
 Inline suggestions are highlighted using the CopilotSuggestion group,

plugin/copilot.vim

@@ -76,3 +76,6 @@ let s:dir = expand('<sfile>:h:h')
 if getftime(s:dir . '/doc/copilot.txt') > getftime(s:dir . '/doc/tags')
   silent! execute 'helptags' fnameescape(s:dir . '/doc')
 endif
+
+imap <silent><nowait><expr> <A-]> copilot#NextResult(1)
+imap <silent><nowait><expr> <A-[> copilot#NextResult(-1)