get_keymap API (#6236)

* Add api function get keymap

nvim_get_keymap(mode)
nvim_buf_get_keymap(buffer, mode)

src/nvim/api/buffer.c

@@ -453,6 +453,26 @@ Integer nvim_buf_get_changedtick(Buffer buffer, Error *err)
   return buf->b_changedtick;
 }
 
+/// Get a list of dictionaries describing buffer-local mappings
+/// Note that the buffer key in the dictionary will represent the buffer
+/// handle where the mapping is present
+///
+/// @param  mode  The abbreviation for the mode
+/// @param  buffer_id  Buffer handle
+/// @param[out]  err   Error details, if any
+/// @returns An array of maparg() like dictionaries describing mappings
+ArrayOf(Dictionary) nvim_buf_get_keymap(Buffer buffer, String mode, Error *err)
+    FUNC_API_SINCE(3)
+{
+  buf_T *buf = find_buffer_by_handle(buffer, err);
+
+  if (!buf) {
+    return (Array)ARRAY_DICT_INIT;
+  }
+
+  return keymap_array(mode, buf);
+}
+
 /// Sets a buffer-scoped (b:) variable
 ///
 /// @param buffer     Buffer handle

src/nvim/api/private/helpers.c

@@ -24,6 +24,7 @@
 #include "nvim/option_defs.h"
 #include "nvim/version.h"
 #include "nvim/lib/kvec.h"
+#include "nvim/getchar.h"
 
 /// Helper structure for vim_to_object
 typedef struct {
@@ -1034,3 +1035,41 @@ void api_set_error(Error *err, ErrorType errType, const char *format, ...)
 
   err->type = errType;
 }
+
+/// Get an array containing dictionaries describing mappings
+/// based on mode and buffer id
+///
+/// @param  mode  The abbreviation for the mode
+/// @param  buf  The buffer to get the mapping array. NULL for global
+/// @returns An array of maparg() like dictionaries describing mappings
+ArrayOf(Dictionary) keymap_array(String mode, buf_T *buf)
+{
+  Array mappings = ARRAY_DICT_INIT;
+  dict_T *const dict = tv_dict_alloc();
+
+  // Convert the string mode to the integer mode
+  // that is stored within each mapblock
+  char_u *p = (char_u *)mode.data;
+  int int_mode = get_map_mode(&p, 0);
+
+  // Determine the desired buffer value
+  long buffer_value = (buf == NULL) ? 0 : buf->handle;
+
+  for (int i = 0; i < MAX_MAPHASH; i++) {
+    for (const mapblock_T *current_maphash = get_maphash(i, buf);
+         current_maphash;
+         current_maphash = current_maphash->m_next) {
+      // Check for correct mode
+      if (int_mode & current_maphash->m_mode) {
+        mapblock_fill_dict(dict, current_maphash, buffer_value, false);
+        ADD(mappings, vim_to_object(
+            (typval_T[]) { { .v_type = VAR_DICT, .vval.v_dict = dict } }));
+
+        tv_dict_clear(dict);
+      }
+    }
+  }
+  tv_dict_free(dict);
+
+  return mappings;
+}

src/nvim/api/vim.c

@@ -742,6 +742,17 @@ Dictionary nvim_get_mode(void)
   return rv;
 }
 
+/// Get a list of dictionaries describing global (i.e. non-buffer) mappings
+/// Note that the "buffer" key will be 0 to represent false.
+///
+/// @param  mode  The abbreviation for the mode
+/// @returns  An array of maparg() like dictionaries describing mappings
+ArrayOf(Dictionary) nvim_get_keymap(String mode)
+    FUNC_API_SINCE(3)
+{
+  return keymap_array(mode, NULL);
+}
+
 Array nvim_get_api_info(uint64_t channel_id)
     FUNC_API_SINCE(1) FUNC_API_ASYNC FUNC_API_REMOTE_ONLY
 {

src/nvim/buffer_defs.h

@@ -438,6 +438,9 @@ typedef TV_DICTITEM_STRUCT(sizeof("changedtick")) ChangedtickDictItem;
 #define BUF_HAS_QF_ENTRY 1
 #define BUF_HAS_LL_ENTRY 2
 
+// Maximum number of maphash blocks we will have
+#define MAX_MAPHASH 256
+
 /*
  * buffer: structure that holds information about one file
  *
@@ -526,8 +529,8 @@ struct file_buffer {
    */
   uint64_t b_chartab[4];
 
-  /* Table used for mappings local to a buffer. */
+  // Table used for mappings local to a buffer.
-  mapblock_T  *(b_maphash[256]);
+  mapblock_T  *(b_maphash[MAX_MAPHASH]);
 
   /* First abbreviation local to a buffer. */
   mapblock_T  *b_first_abbr;

src/nvim/eval.c

@@ -12102,22 +12102,7 @@ static void get_maparg(typval_T *argvars, typval_T *rettv, int exact)
     tv_dict_alloc_ret(rettv);
     if (rhs != NULL) {
       // Return a dictionary.
-      char_u *lhs = str2special_save(mp->m_keys, true);
+      mapblock_fill_dict(rettv->vval.v_dict, mp, buffer_local, true);
-      char *const mapmode = map_mode_to_chars(mp->m_mode);
-      dict_T *dict = rettv->vval.v_dict;
-
-      tv_dict_add_str(dict, S_LEN("lhs"), (const char *)lhs);
-      tv_dict_add_str(dict, S_LEN("rhs"), (const char *)mp->m_orig_str);
-      tv_dict_add_nr(dict, S_LEN("noremap"), mp->m_noremap ? 1 : 0);
-      tv_dict_add_nr(dict, S_LEN("expr"),  mp->m_expr ? 1 : 0);
-      tv_dict_add_nr(dict, S_LEN("silent"), mp->m_silent ? 1 : 0);
-      tv_dict_add_nr(dict, S_LEN("sid"), (varnumber_T)mp->m_script_ID);
-      tv_dict_add_nr(dict, S_LEN("buffer"), (varnumber_T)buffer_local);
-      tv_dict_add_nr(dict, S_LEN("nowait"), mp->m_nowait ? 1 : 0);
-      tv_dict_add_str(dict, S_LEN("mode"), mapmode);
-
-      xfree(lhs);
-      xfree(mapmode);
     }
   }
 }
@@ -12134,6 +12119,46 @@ static void f_luaeval(typval_T *argvars, typval_T *rettv, FunPtr fptr)
   executor_eval_lua(cstr_as_string((char *)str), &argvars[1], rettv);
 }
 
+/// Fill a dictionary with all applicable maparg() like dictionaries
+///
+/// @param  dict  The dictionary to be filled
+/// @param  mp  The maphash that contains the mapping information
+/// @param  buffer_value  The "buffer" value
+/// @param  compatible  True for compatible with old maparg() dict
+void mapblock_fill_dict(dict_T *const dict,
+                        const mapblock_T *const mp,
+                        long buffer_value,
+                        bool compatible)
+    FUNC_ATTR_NONNULL_ALL
+{
+  char_u *lhs = str2special_save(mp->m_keys, true);
+  char *const mapmode = map_mode_to_chars(mp->m_mode);
+  varnumber_T noremap_value;
+
+  if (compatible) {
+    // Keep old compatible behavior
+    // This is unable to determine whether a mapping is a <script> mapping
+    noremap_value = !!mp->m_noremap;
+  } else {
+    // Distinguish between <script> mapping
+    // If it's not a <script> mapping, check if it's a noremap
+    noremap_value = mp->m_noremap == REMAP_SCRIPT ? 2 : !!mp->m_noremap;
+  }
+
+  tv_dict_add_str(dict, S_LEN("lhs"), (const char *)lhs);
+  tv_dict_add_str(dict, S_LEN("rhs"), (const char *)mp->m_orig_str);
+  tv_dict_add_nr(dict, S_LEN("noremap"), noremap_value);
+  tv_dict_add_nr(dict, S_LEN("expr"),  mp->m_expr ? 1 : 0);
+  tv_dict_add_nr(dict, S_LEN("silent"), mp->m_silent ? 1 : 0);
+  tv_dict_add_nr(dict, S_LEN("sid"), (varnumber_T)mp->m_script_ID);
+  tv_dict_add_nr(dict, S_LEN("buffer"), (varnumber_T)buffer_value);
+  tv_dict_add_nr(dict, S_LEN("nowait"), mp->m_nowait ? 1 : 0);
+  tv_dict_add_str(dict, S_LEN("mode"), mapmode);
+
+  xfree(lhs);
+  xfree(mapmode);
+}
+
 /*
  * "map()" function
  */

src/nvim/getchar.c

@@ -18,6 +18,7 @@
 #include "nvim/vim.h"
 #include "nvim/ascii.h"
 #include "nvim/getchar.h"
+#include "nvim/buffer_defs.h"
 #include "nvim/charset.h"
 #include "nvim/cursor.h"
 #include "nvim/edit.h"
@@ -47,6 +48,7 @@
 #include "nvim/event/loop.h"
 #include "nvim/os/input.h"
 #include "nvim/os/os.h"
+#include "nvim/api/private/handle.h"
 
 /*
  * These buffers are used for storing:
@@ -102,11 +104,10 @@ static int block_redo = FALSE;
                        (NORMAL + VISUAL + SELECTMODE + \
                         OP_PENDING)) ? (c1) : ((c1) ^ 0x80))
 
-/*
+// Each mapping is put in one of the MAX_MAPHASH hash lists,
- * Each mapping is put in one of the 256 hash lists, to speed up finding it.
+// to speed up finding it.
- */
+static mapblock_T *(maphash[MAX_MAPHASH]);
-static mapblock_T       *(maphash[256]);
+static bool maphash_valid = false;
-static int maphash_valid = FALSE;
 
 /*
  * List used for abbreviations.
@@ -4237,3 +4238,17 @@ static bool typebuf_match_len(const uint8_t *str, int *mlen)
   *mlen = i;
   return str[i] == NUL;  // matched the whole string
 }
+
+/// Retrieve the mapblock at the index either globally or for a certain buffer
+///
+/// @param  index  The index in the maphash[]
+/// @param  buf  The buffer to get the maphash from. NULL for global
+mapblock_T *get_maphash(int index, buf_T *buf)
+    FUNC_ATTR_PURE
+{
+  if (index > MAX_MAPHASH) {
+    return NULL;
+  }
+
+  return (buf == NULL) ? maphash[index] : buf->b_maphash[index];
+}

test/functional/api/keymap_spec.lua

@@ -0,0 +1,246 @@
+
+local helpers = require('test.functional.helpers')(after_each)
+local clear = helpers.clear
+local command = helpers.command
+local curbufmeths = helpers.curbufmeths
+local eq = helpers.eq
+local funcs = helpers.funcs
+local meths = helpers.meths
+local source = helpers.source
+
+local function local_copy(t)
+  local copy = {}
+  for k,v in pairs(t) do
+    copy[k] = v
+  end
+  return copy
+end
+
+describe('get_keymap', function()
+  before_each(clear)
+
+  -- Basic mapping and table to be used to describe results
+  local foo_bar_string = 'nnoremap foo bar'
+  local foo_bar_map_table = {
+      lhs='foo',
+      silent=0,
+      rhs='bar',
+      expr=0,
+      sid=0,
+      buffer=0,
+      nowait=0,
+      mode='n',
+      noremap=1,
+    }
+
+  it('returns empty list when no map', function()
+    eq({}, meths.get_keymap('n'))
+  end)
+
+  it('returns list of all applicable mappings', function()
+    command(foo_bar_string)
+    -- Only one mapping available
+    -- Should be the same as the dictionary we supplied earlier
+    -- and the dictionary you would get from maparg
+    -- since this is a global map, and not script local
+    eq({foo_bar_map_table}, meths.get_keymap('n'))
+    eq({funcs.maparg('foo', 'n', false, true)},
+      meths.get_keymap('n')
+    )
+
+    -- Add another mapping
+    command('nnoremap foo_longer bar_longer')
+    local foolong_bar_map_table = local_copy(foo_bar_map_table)
+    foolong_bar_map_table['lhs'] = 'foo_longer'
+    foolong_bar_map_table['rhs'] = 'bar_longer'
+
+    eq({foolong_bar_map_table, foo_bar_map_table},
+      meths.get_keymap('n')
+    )
+
+    -- Remove a mapping
+    command('unmap foo_longer')
+    eq({foo_bar_map_table},
+      meths.get_keymap('n')
+    )
+  end)
+
+  it('works for other modes', function()
+    -- Add two mappings, one in insert and one normal
+    -- We'll only check the insert mode one
+    command('nnoremap not_going to_check')
+
+    command('inoremap foo bar')
+    -- The table will be the same except for the mode
+    local insert_table = local_copy(foo_bar_map_table)
+    insert_table['mode'] = 'i'
+
+    eq({insert_table}, meths.get_keymap('i'))
+  end)
+
+  it('considers scope', function()
+    -- change the map slightly
+    command('nnoremap foo_longer bar_longer')
+    local foolong_bar_map_table = local_copy(foo_bar_map_table)
+    foolong_bar_map_table['lhs'] = 'foo_longer'
+    foolong_bar_map_table['rhs'] = 'bar_longer'
+
+    local buffer_table = local_copy(foo_bar_map_table)
+    buffer_table['buffer'] = 1
+
+    command('nnoremap <buffer> foo bar')
+
+    -- The buffer mapping should not show up
+    eq({foolong_bar_map_table}, meths.get_keymap('n'))
+    eq({buffer_table}, curbufmeths.get_keymap('n'))
+  end)
+
+  it('considers scope for overlapping maps', function()
+    command('nnoremap foo bar')
+
+    local buffer_table = local_copy(foo_bar_map_table)
+    buffer_table['buffer'] = 1
+
+    command('nnoremap <buffer> foo bar')
+
+    eq({foo_bar_map_table}, meths.get_keymap('n'))
+    eq({buffer_table}, curbufmeths.get_keymap('n'))
+  end)
+
+  it('can retrieve mapping for different buffers', function()
+    local original_buffer = curbufmeths.get_number()
+    -- Place something in each of the buffers to make sure they stick around
+    -- and set hidden so we can leave them
+    command('set hidden')
+    command('new')
+    command('normal! ihello 2')
+    command('new')
+    command('normal! ihello 3')
+
+    local final_buffer = curbufmeths.get_number()
+
+    command('nnoremap <buffer> foo bar')
+    -- Final buffer will have buffer mappings
+    local buffer_table = local_copy(foo_bar_map_table)
+    buffer_table['buffer'] = final_buffer
+    eq({buffer_table}, meths.buf_get_keymap(final_buffer, 'n'))
+    eq({buffer_table}, meths.buf_get_keymap(0, 'n'))
+
+    command('buffer ' .. original_buffer)
+    eq(original_buffer, curbufmeths.get_number())
+    -- Original buffer won't have any mappings
+    eq({}, meths.get_keymap('n'))
+    eq({}, curbufmeths.get_keymap('n'))
+    eq({buffer_table}, meths.buf_get_keymap(final_buffer, 'n'))
+  end)
+
+  -- Test toggle switches for basic options
+  -- @param  option  The key represented in the `maparg()` result dict
+  local function global_and_buffer_test(map,
+                                        option,
+                                        option_token,
+                                        global_on_result,
+                                        buffer_on_result,
+                                        global_off_result,
+                                        buffer_off_result,
+                                        new_windows)
+
+    local function make_new_windows(number_of_windows)
+      if new_windows == nil then
+        return nil
+      end
+
+      for _=1,number_of_windows do
+        command('new')
+      end
+    end
+
+    local mode = string.sub(map, 1,1)
+    -- Don't run this for the <buffer> mapping, since it doesn't make sense
+    if option_token ~= '<buffer>' then
+      it(string.format( 'returns %d for the key "%s" when %s is used globally with %s (%s)',
+          global_on_result, option, option_token, map, mode), function()
+        make_new_windows(new_windows)
+        command(map .. ' ' .. option_token .. ' foo bar')
+        local result = meths.get_keymap(mode)[1][option]
+        eq(global_on_result, result)
+      end)
+    end
+
+    it(string.format('returns %d for the key "%s" when %s is used for buffers with %s (%s)',
+        buffer_on_result, option, option_token, map, mode), function()
+      make_new_windows(new_windows)
+      command(map .. ' <buffer> ' .. option_token .. ' foo bar')
+      local result = curbufmeths.get_keymap(mode)[1][option]
+      eq(buffer_on_result, result)
+    end)
+
+    -- Don't run these for the <buffer> mapping, since it doesn't make sense
+    if option_token ~= '<buffer>' then
+      it(string.format('returns %d for the key "%s" when %s is not used globally with %s (%s)',
+          global_off_result, option, option_token, map, mode), function()
+        make_new_windows(new_windows)
+        command(map .. ' baz bat')
+        local result = meths.get_keymap(mode)[1][option]
+        eq(global_off_result, result)
+      end)
+
+      it(string.format('returns %d for the key "%s" when %s is not used for buffers with %s (%s)',
+          buffer_off_result, option, option_token, map, mode), function()
+        make_new_windows(new_windows)
+        command(map .. ' <buffer> foo bar')
+
+        local result = curbufmeths.get_keymap(mode)[1][option]
+        eq(buffer_off_result, result)
+      end)
+    end
+  end
+
+  -- Standard modes and returns the same values in the dictionary as maparg()
+  local mode_list = {'nnoremap', 'nmap', 'imap', 'inoremap', 'cnoremap'}
+  for mode in pairs(mode_list) do
+    global_and_buffer_test(mode_list[mode], 'silent', '<silent>', 1, 1, 0, 0)
+    global_and_buffer_test(mode_list[mode], 'nowait', '<nowait>', 1, 1, 0, 0)
+    global_and_buffer_test(mode_list[mode], 'expr', '<expr>', 1, 1, 0, 0)
+  end
+
+  -- noremap will now be 2 if script was used, which is not the same as maparg()
+  global_and_buffer_test('nmap', 'noremap', '<script>', 2, 2, 0, 0)
+  global_and_buffer_test('nnoremap', 'noremap', '<script>', 2, 2, 1, 1)
+
+  -- buffer will return the buffer ID, which is not the same as maparg()
+  -- Three of these tests won't run
+  global_and_buffer_test('nnoremap', 'buffer', '<buffer>', nil, 3, nil, nil, 2)
+
+  it('returns script numbers for global maps', function()
+    source([[
+      function! s:maparg_test_function() abort
+        return 'testing'
+      endfunction
+
+      nnoremap fizz :call <SID>maparg_test_function()<CR>
+    ]])
+    local sid_result = meths.get_keymap('n')[1]['sid']
+    eq(1, sid_result)
+    eq('testing', meths.call_function('<SNR>' .. sid_result .. '_maparg_test_function', {}))
+  end)
+
+  it('returns script numbers for buffer maps', function()
+    source([[
+      function! s:maparg_test_function() abort
+        return 'testing'
+      endfunction
+
+      nnoremap <buffer> fizz :call <SID>maparg_test_function()<CR>
+    ]])
+    local sid_result = curbufmeths.get_keymap('n')[1]['sid']
+    eq(1, sid_result)
+    eq('testing', meths.call_function('<SNR>' .. sid_result .. '_maparg_test_function', {}))
+  end)
+
+  it('works with <F12> and others', function()
+    command('nnoremap <F12> :let g:maparg_test_var = 1<CR>')
+    eq('<F12>', meths.get_keymap('n')[1]['lhs'])
+    eq(':let g:maparg_test_var = 1<CR>', meths.get_keymap('n')[1]['rhs'])
+  end)
+end)

test/functional/eval/map_functions_spec.lua

@@ -0,0 +1,120 @@
+
+local helpers = require('test.functional.helpers')(after_each)
+local clear = helpers.clear
+local eq = helpers.eq
+local eval = helpers.eval
+local funcs = helpers.funcs
+local nvim = helpers.nvim
+local source = helpers.source
+
+describe('maparg()', function()
+  before_each(clear)
+
+  local foo_bar_map_table = {
+      lhs='foo',
+      silent=0,
+      rhs='bar',
+      expr=0,
+      sid=0,
+      buffer=0,
+      nowait=0,
+      mode='n',
+      noremap=1,
+    }
+
+  it('returns a dictionary', function()
+    nvim('command', 'nnoremap foo bar')
+    eq('bar', funcs.maparg('foo'))
+    eq(foo_bar_map_table, funcs.maparg('foo', 'n', false, true))
+  end)
+
+  it('returns 1 for silent when <silent> is used', function()
+    nvim('command', 'nnoremap <silent> foo bar')
+    eq(1, funcs.maparg('foo', 'n', false, true)['silent'])
+
+    nvim('command', 'nnoremap baz bat')
+    eq(0, funcs.maparg('baz', 'n', false, true)['silent'])
+  end)
+
+  it('returns an empty string when no map is present', function()
+    eq('', funcs.maparg('not a mapping'))
+  end)
+
+  it('returns an empty dictionary when no map is present and dict is requested', function()
+    eq({}, funcs.maparg('not a mapping', 'n', false, true))
+  end)
+
+  it('returns the same value for noremap and <script>', function()
+    nvim('command', 'inoremap <script> hello world')
+    nvim('command', 'inoremap this that')
+    eq(
+      funcs.maparg('hello', 'i', false, true)['noremap'],
+      funcs.maparg('this', 'i', false, true)['noremap']
+      )
+  end)
+
+  it('returns a boolean for buffer', function()
+    -- Open enough windows to know we aren't on buffer number 1
+    nvim('command', 'new')
+    nvim('command', 'new')
+    nvim('command', 'new')
+    nvim('command', 'cnoremap <buffer> this that')
+    eq(1, funcs.maparg('this', 'c', false, true)['buffer'])
+
+    -- Global will return 0 always
+    nvim('command', 'nnoremap other another')
+    eq(0, funcs.maparg('other', 'n', false, true)['buffer'])
+  end)
+
+  it('returns script numbers', function()
+    source([[
+      function! s:maparg_test_function() abort
+        return 'testing'
+      endfunction
+
+      nnoremap fizz :call <SID>maparg_test_function()<CR>
+    ]])
+    eq(1, funcs.maparg('fizz', 'n', false, true)['sid'])
+    eq('testing', nvim('call_function', '<SNR>1_maparg_test_function', {}))
+  end)
+
+  it('works with <F12> and others', function()
+    source([[
+      let g:maparg_test_var = 0
+
+      nnoremap <F12> :let g:maparg_test_var = 1<CR>
+    ]])
+    eq(0, eval('g:maparg_test_var'))
+    source([[
+      call feedkeys("\<F12>")
+    ]])
+    eq(1, eval('g:maparg_test_var'))
+
+    eq(':let g:maparg_test_var = 1<CR>', funcs.maparg('<F12>', 'n', false, true)['rhs'])
+  end)
+
+  it('works with <expr>', function()
+    source([[
+      let counter = 0
+      inoremap <expr> <C-L> ListItem()
+      inoremap <expr> <C-R> ListReset()
+
+      func ListItem()
+        let g:counter += 1
+        return g:counter . '. '
+      endfunc
+
+      func ListReset()
+        let g:counter = 0
+        return ''
+      endfunc
+
+      call feedkeys("i\<C-L>")
+    ]])
+    eq(1, eval('g:counter'))
+
+    local map_dict = funcs.maparg('<C-L>', 'i', false, true)
+    eq(1, map_dict['expr'])
+    eq('i', map_dict['mode'])
+  end)
+end)