support lua5.5 grammar

[CppCXY]

No description provided.

[MunifTanjim]

Thanks! I'm gonna take a look at it soon.

[MunifTanjim]

Can you please apply this patch? I can't push to this branch as it seems...

diff --git a/grammar.js b/grammar.js
index 4604fcf..33681f5 100644
--- a/grammar.js
+++ b/grammar.js
@@ -84,7 +84,10 @@ module.exports = grammar({
                 for namelist in explist do block end |
                 function funcname funcbody |
                 local function Name funcbody |
-                local namelist ['=' explist]
+                global function Name funcbody | 
+                local attnamelist ['=' explist] |
+                global attnamelist ['=' explist] |
+                global [attrib] ‘*’
     */
     statement: ($) =>
       choice(
@@ -100,14 +103,6 @@ module.exports = grammar({
         $.if_statement,
         $.for_statement,
         $.declaration,
-        $.global_mode_statement
-      ),
-    // global * | global <attrib> * [Lua 5.5]
-    global_mode_statement: ($) =>
-      seq(
-        'global',
-        optional(field('attribute', alias($._attrib, $.attribute))),
-        '*'
       ),
 
     // retstat ::= return [explist] [';']
@@ -215,12 +210,15 @@ module.exports = grammar({
         field('end', $.expression),
         optional(seq(',', field('step', $.expression)))
       ),
+    // namelist ::= Name {',' Name}
+    _name_list: ($) => name_list($),
 
     // function funcname funcbody
     // local function Name funcbody
-    // local namelist ['=' explist]
-    // global function Name funcbody [Lua 5.5]
-    // global namelist ['=' explist] [Lua 5.5]
+    // global function Name funcbody
+    // local attnamelist [‘=’ explist]
+    // global attnamelist [‘=’ explist]
+    // global [attrib] ‘*’
     declaration: ($) =>
       choice(
         $.function_declaration,
@@ -233,7 +231,14 @@ module.exports = grammar({
           'global_declaration',
           alias($._global_function_declaration, $.function_declaration)
         ),
-        field('global_declaration', $.global_variable_declaration)
+        field(
+          'global_declaration',
+          alias($._global_variable_declaration, $.variable_declaration)
+        ),
+        field(
+          'global_declaration',
+          alias($._global_implicit_variable_declaration, $.implicit_variable_declaration)
+        )
       ),
     // function funcname funcbody
     function_declaration: ($) =>
@@ -241,7 +246,7 @@ module.exports = grammar({
     // local function Name funcbody
     _local_function_declaration: ($) =>
       seq('local', 'function', field('name', $.identifier), $._function_body),
-    // global function Name funcbody [Lua 5.5]
+    // global function Name funcbody
     _global_function_declaration: ($) =>
       seq('global', 'function', field('name', $.identifier), $._function_body),
     // funcname ::= Name {'.' Name} [':' Name]
@@ -271,65 +276,52 @@ module.exports = grammar({
         field('method', $.identifier)
       ),
 
-    // local namelist ['=' explist]
+    // local attnamelist [‘=’ explist]
     variable_declaration: ($) =>
       seq(
         'local',
         choice(
           alias($._att_name_list, $.variable_list),
-          alias($._local_variable_assignment, $.assignment_statement)
+          alias($._variable_assignment, $.assignment_statement)
         )
       ),
-    // global namelist ['=' explist] [Lua 5.5]
-    // global <attrib> namelist ['=' explist] [Lua 5.5]
-    global_variable_declaration: ($) =>
+    // global attnamelist [‘=’ explist]
+    _global_variable_declaration: ($) =>
       seq(
         'global',
         choice(
-          // global <attrib> namelist ['=' explist]
-          seq(
-            field('attribute', alias($._attrib, $.attribute)),
-            choice(
-              alias($._name_list, $.variable_list),
-              alias($._global_prefixed_variable_assignment, $.assignment_statement)
-            )
-          ),
-          // global namelist ['=' explist]
           alias($._att_name_list, $.variable_list),
-          alias($._global_variable_assignment, $.assignment_statement)
+          alias($._variable_assignment, $.assignment_statement),
         )
       ),
-    _local_variable_assignment: ($) =>
+    // attnamelist ‘=’ explist
+    _variable_assignment: ($) =>
       seq(
         alias($._att_name_list, $.variable_list),
         '=',
         alias($._variable_assignment_explist, $.expression_list)
       ),
-    _global_variable_assignment: ($) =>
-      seq(
-        alias($._att_name_list, $.variable_list),
-        '=',
-        alias($._variable_assignment_explist, $.expression_list)
-      ),
-    _global_prefixed_variable_assignment: ($) =>
-      seq(
-        alias($._name_list, $.variable_list),
-        '=',
-        alias($._variable_assignment_explist, $.expression_list)
-      ),
-    // namelist ::= Name {',' Name}
-    _name_list: ($) => name_list($),
 
-    // attnamelist ::=  Name attrib {‘,’ Name attrib}
+    // attnamelist ::= [attrib] Name [attrib] {‘,’ Name [attrib]}
     _att_name_list: ($) =>
-      list_seq(
-        seq(
-          field('name', $.identifier),
-          optional(field('attribute', alias($._attrib, $.attribute)))
+      seq(
+        optional(field('attribute', alias($._attrib, $.attribute))),
+        list_seq(
+          seq(
+            field('name', $.identifier),
+            optional(field('attribute', alias($._attrib, $.attribute)))
+          ),
+          ','
         ),
-        ','
       ),
-    // attrib ::= [‘<’ Name ‘>’]
+    // global [attrib] ‘*’
+    _global_implicit_variable_declaration: ($) =>
+      seq(
+        'global',
+        optional(field('attribute', alias($._attrib, $.attribute))),
+        '*'
+      ),
+    // attrib ::= ‘<’ Name ‘>’
     _attrib: ($) => seq('<', $.identifier, '>'),
 
     // explist ::= exp {',' exp}
@@ -478,15 +470,15 @@ module.exports = grammar({
       ),
     // '(' [parlist] ')'
     parameters: ($) => seq('(', optional($._parameter_list), ')'),
-    // parlist ::= namelist [',' '...'] | '...' | namelist [',' '...' Name] | '...' Name [Lua 5.5]
+    // parlist ::= namelist [‘,’ varargparam] | varargparam
     _parameter_list: ($) =>
       choice(
-        seq(name_list($), optional(seq(',', choice($.vararg_expression, $.named_vararg)))),
-        $.vararg_expression,
-        $.named_vararg
+        seq(name_list($), optional(seq(',', $._vararg_parameter))),
+        $._vararg_parameter
       ),
-    // '...' Name [Lua 5.5]
-    named_vararg: ($) => seq('...', field('name', $.identifier)),
+    // varargparam ::= ‘...’ [Name]
+    _vararg_parameter: ($) =>
+      seq($.vararg_expression, optional(field('name', $.identifier))),
 
     // prefixexp ::= var | functioncall | '(' exp ')'
     _prefix_expression: ($) =>

[MunifTanjim]

@clason @ObserverOfTime

For the new named vararg, the non-breaking change looks like this:

function a(x, y, ...x) end

function a(x, y, ...) end

But the more proper way would be to make a breaking change (imo).

Do you think the breaking change would be too much?

[clason]

(You can't push because the PR was not opened from a feature branch but the main branch.)

Since the parser is a critical component of Neovim, I would prefer to avoid breaking changes as much as possible -- certainly if the motivation is a (so far) niche feature like Lua 5.5. I also worry about the complexity this change adds (although it seems minor).

Let me push a bit of additional CI so we can see the actual fallout of this change.

[clason]

Alternative would be to add a choice between (vararg) and (named_vararg)? That could complicate things further, though.

[MunifTanjim]

This one is good enough that doesn't have any breaking changes. We can merge after the patch I added is applied.

[clason]

First my PR, then a rebase ;)

[clason]

@CppCXY could you please open a new PR from a branch created from the tip(!) of main? Otherwise we can't fix merge issues.