lua: metatable for empty dict value

This commit is contained in:
Björn Linse 2019-11-27 20:45:41 +01:00
parent a251b588ac
commit ea4127e9a7
8 changed files with 101 additions and 4 deletions

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@ -717,6 +717,16 @@ vim.NIL *vim.NIL*
is equivalent to a missing value: `{"foo", nil}` is the same as is equivalent to a missing value: `{"foo", nil}` is the same as
`{"foo"}` `{"foo"}`
vim.empty_dict() *vim.empty_dict()*
Creates a special table which will be converted to an empty
dictionary when converting lua values to vimL or API types. The
table is empty, and this property is marked using a metatable. An
empty table `{}` without this metatable will default to convert to
an array/list.
Note: if numeric keys are added to the table, the metatable will be
ignored and the dict converted to a list/array anyway.
vim.rpcnotify({channel}, {method}[, {args}...]) *vim.rpcnotify()* vim.rpcnotify({channel}, {method}[, {args}...]) *vim.rpcnotify()*
Sends {event} to {channel} via |RPC| and returns immediately. Sends {event} to {channel} via |RPC| and returns immediately.
If {channel} is 0, the event is broadcast to all channels. If {channel} is 0, the event is broadcast to all channels.

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@ -244,6 +244,11 @@ function Inspector:putTable(t)
local nonSequentialKeys, nonSequentialKeysLength, sequenceLength = getNonSequentialKeys(t) local nonSequentialKeys, nonSequentialKeysLength, sequenceLength = getNonSequentialKeys(t)
local mt = getmetatable(t) local mt = getmetatable(t)
if (vim and sequenceLength == 0 and nonSequentialKeysLength == 0
and mt == vim._empty_dict_mt) then
self:puts(tostring(t))
return
end
self:puts('{') self:puts('{')
self:down(function() self:down(function()

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@ -275,9 +275,15 @@ function vim.tbl_flatten(t)
end end
-- Determine whether a Lua table can be treated as an array. -- Determine whether a Lua table can be treated as an array.
--
-- An empty table `{}` will default to being treated as an array.
-- Use `vim.emtpy_dict()` to create a table treated as an
-- empty dict. Empty tables returned by `rpcrequest()` and
-- `vim.fn` functions can be checked using this function
-- whether they represent empty API arrays and vimL lists.
--- ---
--@params Table --@params Table
--@returns true: A non-empty array, false: A non-empty table, nil: An empty table --@returns true: An array-like table, false: A dict-like or mixed table
function vim.tbl_islist(t) function vim.tbl_islist(t)
if type(t) ~= 'table' then if type(t) ~= 'table' then
return false return false
@ -296,7 +302,12 @@ function vim.tbl_islist(t)
if count > 0 then if count > 0 then
return true return true
else else
return nil -- TODO(bfredl): in the future, we will always be inside nvim
-- then this check can be deleted.
if vim._empty_dict_mt == nil then
return nil
end
return getmetatable(t) ~= vim._empty_dict_mt
end end
end end

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@ -156,6 +156,13 @@ static LuaTableProps nlua_traverse_table(lua_State *const lstate)
&& other_keys_num == 0 && other_keys_num == 0
&& ret.string_keys_num == 0)) { && ret.string_keys_num == 0)) {
ret.type = kObjectTypeArray; ret.type = kObjectTypeArray;
if (tsize == 0 && lua_getmetatable(lstate, -1)) {
nlua_pushref(lstate, nlua_empty_dict_ref);
if (lua_rawequal(lstate, -2, -1)) {
ret.type = kObjectTypeDictionary;
}
lua_pop(lstate, 2);
}
} else if (ret.string_keys_num == tsize) { } else if (ret.string_keys_num == tsize) {
ret.type = kObjectTypeDictionary; ret.type = kObjectTypeDictionary;
} else { } else {
@ -465,6 +472,8 @@ static bool typval_conv_special = false;
nlua_create_typed_table(lstate, 0, 0, kObjectTypeDictionary); \ nlua_create_typed_table(lstate, 0, 0, kObjectTypeDictionary); \
} else { \ } else { \
lua_createtable(lstate, 0, 0); \ lua_createtable(lstate, 0, 0); \
nlua_pushref(lstate, nlua_empty_dict_ref); \
lua_setmetatable(lstate, -2); \
} \ } \
} while (0) } while (0)
@ -695,6 +704,10 @@ void nlua_push_Dictionary(lua_State *lstate, const Dictionary dict,
nlua_create_typed_table(lstate, 0, 0, kObjectTypeDictionary); nlua_create_typed_table(lstate, 0, 0, kObjectTypeDictionary);
} else { } else {
lua_createtable(lstate, 0, (int)dict.size); lua_createtable(lstate, 0, (int)dict.size);
if (dict.size == 0 && !special) {
nlua_pushref(lstate, nlua_empty_dict_ref);
lua_setmetatable(lstate, -2);
}
} }
for (size_t i = 0; i < dict.size; i++) { for (size_t i = 0; i < dict.size; i++) {
nlua_push_String(lstate, dict.items[i].key, special); nlua_push_String(lstate, dict.items[i].key, special);

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@ -324,6 +324,13 @@ static int nlua_state_init(lua_State *const lstate) FUNC_ATTR_NONNULL_ALL
nlua_nil_ref = nlua_ref(lstate, -1); nlua_nil_ref = nlua_ref(lstate, -1);
lua_setfield(lstate, -2, "NIL"); lua_setfield(lstate, -2, "NIL");
// vim._empty_dict_mt
lua_createtable(lstate, 0, 0);
lua_pushcfunction(lstate, &nlua_empty_dict_tostring);
lua_setfield(lstate, -2, "__tostring");
nlua_empty_dict_ref = nlua_ref(lstate, -1);
lua_setfield(lstate, -2, "_empty_dict_mt");
// internal vim._treesitter... API // internal vim._treesitter... API
nlua_add_treesitter(lstate); nlua_add_treesitter(lstate);
@ -665,6 +672,12 @@ static int nlua_nil_tostring(lua_State *lstate)
return 1; return 1;
} }
static int nlua_empty_dict_tostring(lua_State *lstate)
{
lua_pushstring(lstate, "vim.empty_dict()");
return 1;
}
#ifdef WIN32 #ifdef WIN32
/// os.getenv: override os.getenv to maintain coherency. #9681 /// os.getenv: override os.getenv to maintain coherency. #9681

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@ -13,6 +13,7 @@
void nlua_add_api_functions(lua_State *lstate) REAL_FATTR_NONNULL_ALL; void nlua_add_api_functions(lua_State *lstate) REAL_FATTR_NONNULL_ALL;
EXTERN LuaRef nlua_nil_ref INIT(= LUA_NOREF); EXTERN LuaRef nlua_nil_ref INIT(= LUA_NOREF);
EXTERN LuaRef nlua_empty_dict_ref INIT(= LUA_NOREF);
#define set_api_error(s, err) \ #define set_api_error(s, err) \
do { \ do { \

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@ -243,6 +243,10 @@ function vim.schedule_wrap(cb)
end) end)
end end
function vim.empty_dict()
return setmetatable({}, vim._empty_dict_mt)
end
-- vim.fn.{func}(...) -- vim.fn.{func}(...)
vim.fn = setmetatable({}, { vim.fn = setmetatable({}, {
__index = function(t, key) __index = function(t, key)

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@ -354,7 +354,8 @@ describe('lua stdlib', function()
end) end)
it('vim.tbl_islist', function() it('vim.tbl_islist', function()
eq(NIL, exec_lua("return vim.tbl_islist({})")) eq(true, exec_lua("return vim.tbl_islist({})"))
eq(false, exec_lua("return vim.tbl_islist(vim.empty_dict())"))
eq(true, exec_lua("return vim.tbl_islist({'a', 'b', 'c'})")) eq(true, exec_lua("return vim.tbl_islist({'a', 'b', 'c'})"))
eq(false, exec_lua("return vim.tbl_islist({'a', '32', a='hello', b='baz'})")) eq(false, exec_lua("return vim.tbl_islist({'a', '32', a='hello', b='baz'})"))
eq(false, exec_lua("return vim.tbl_islist({1, a='hello', b='baz'})")) eq(false, exec_lua("return vim.tbl_islist({1, a='hello', b='baz'})"))
@ -458,6 +459,19 @@ describe('lua stdlib', function()
]])) ]]))
eq({3, 'aa', true, NIL}, exec_lua([[return ret]])) eq({3, 'aa', true, NIL}, exec_lua([[return ret]]))
eq({{}, {}, false, true}, exec_lua([[
vim.rpcrequest(chan, 'nvim_exec', 'let xx = {}\nlet yy = []', false)
local dict = vim.rpcrequest(chan, 'nvim_eval', 'xx')
local list = vim.rpcrequest(chan, 'nvim_eval', 'yy')
return {dict, list, vim.tbl_islist(dict), vim.tbl_islist(list)}
]]))
exec_lua([[
vim.rpcrequest(chan, 'nvim_set_var', 'aa', {})
vim.rpcrequest(chan, 'nvim_set_var', 'bb', vim.empty_dict())
]])
eq({1, 1}, eval('[type(g:aa) == type([]), type(g:bb) == type({})]'))
-- error handling -- error handling
eq({false, 'Invalid channel: 23'}, eq({false, 'Invalid channel: 23'},
exec_lua([[return {pcall(vim.rpcrequest, 23, 'foo')}]])) exec_lua([[return {pcall(vim.rpcrequest, 23, 'foo')}]]))
@ -486,7 +500,7 @@ describe('lua stdlib', function()
}) })
screen:attach() screen:attach()
exec_lua([[ exec_lua([[
local timer = vim.loop.new_timer() timer = vim.loop.new_timer()
timer:start(20, 0, function () timer:start(20, 0, function ()
-- notify ok (executed later when safe) -- notify ok (executed later when safe)
vim.rpcnotify(chan, 'nvim_set_var', 'yy', {3, vim.NIL}) vim.rpcnotify(chan, 'nvim_set_var', 'yy', {3, vim.NIL})
@ -505,6 +519,32 @@ describe('lua stdlib', function()
]]} ]]}
feed('<cr>') feed('<cr>')
eq({3, NIL}, meths.get_var('yy')) eq({3, NIL}, meths.get_var('yy'))
exec_lua([[timer:close()]])
end)
it('vim.empty_dict()', function()
eq({true, false, true, true}, exec_lua([[
vim.api.nvim_set_var('listy', {})
vim.api.nvim_set_var('dicty', vim.empty_dict())
local listy = vim.fn.eval("listy")
local dicty = vim.fn.eval("dicty")
return {vim.tbl_islist(listy), vim.tbl_islist(dicty), next(listy) == nil, next(dicty) == nil}
]]))
-- vim.empty_dict() gives new value each time
-- equality is not overriden (still by ref)
-- non-empty table uses the usual heuristics (ignores the tag)
eq({false, {"foo"}, {namey="bar"}}, exec_lua([[
local aa = vim.empty_dict()
local bb = vim.empty_dict()
local equally = (aa == bb)
aa[1] = "foo"
bb["namey"] = "bar"
return {equally, aa, bb}
]]))
eq("{ {}, vim.empty_dict() }", exec_lua("return vim.inspect({{}, vim.empty_dict()})"))
end) end)
it('vim.validate', function() it('vim.validate', function()