feat: add ApX parser

ApX is a command-oriented scripting language for the APEX PDE (Personal
Development Environment). It features pipelines, 200+ built-in commands,
control flow, functions, macros, and more.

Grammar repository: https://github.com/StackApe/tree-sitter-apx

lua/nvim-treesitter/parsers.lua

@@ -34,6 +34,14 @@ return {
     maintainers = { '@aheber', '@xixiafinland' },
     tier = 2,
   },
+  apx = {
+    install_info = {
+      revision = 'b4998766b748d9559a5d1752b76b2719721bd096',
+      url = 'https://github.com/StackApe/tree-sitter-apx',
+    },
+    maintainers = { '@StackApe' },
+    tier = 2,
+  },
   arduino = {
     install_info = {
       revision = '53eb391da4c6c5857f8defa2c583c46c2594f565',

queries/apx/highlights.scm

@@ -0,0 +1,161 @@
+; ApX Tree-sitter highlight queries for Neovim
+
+; Comments
+(comment) @comment
+
+; Strings
+(double_string) @string
+(single_string) @string
+(triple_string) @string
+(raw_string) @string
+(backtick_string) @string
+
+; Numbers
+(integer) @number
+(float) @number.float
+(hex_number) @number
+(binary_number) @number
+(octal_number) @number
+
+; Booleans and null
+(boolean) @boolean
+(null) @constant.builtin
+
+; Variables
+(regular_variable) @variable
+(env_variable) @variable.builtin
+(special_variable) @variable.builtin
+
+; Field access: $var.field
+(field_access
+  (identifier) @property)
+
+; Method calls: ai.ask
+(method_call
+  (identifier) @function.call)
+
+; Keywords - Control flow (using actual grammar keywords)
+"if" @keyword.control
+"else" @keyword.control
+"elif" @keyword.control
+"for" @keyword.control
+"while" @keyword.control
+"in" @keyword.control
+"match" @keyword.control
+"return" @keyword.control
+
+; Break and continue are statement nodes
+(break_statement) @keyword.control
+(continue_statement) @keyword.control
+
+; Keywords - Definition
+"fn" @keyword.function
+"macro" @keyword.function
+"alias" @keyword.function
+"let" @keyword.function
+"const" @keyword.function
+"set" @keyword.function
+
+; Keywords - Error handling
+"try" @keyword.exception
+"catch" @keyword.exception
+
+; Keywords - Modules
+"use" @keyword.import
+"from" @keyword.import
+"import" @keyword.import
+"as" @keyword.import
+
+; Keywords - Testing
+"test" @keyword
+
+; Keywords - Logical
+"and" @keyword.operator
+"or" @keyword.operator
+"not" @keyword.operator
+
+; Operators
+[
+  "+"
+  "-"
+  "*"
+  "/"
+  "%"
+  "=="
+  "!="
+  "<"
+  ">"
+  "<="
+  ">="
+  "&&"
+  "||"
+  "!"
+  "="
+  "|"
+  ".."
+  "..="
+  "=>"
+] @operator
+
+; Punctuation
+[
+  "("
+  ")"
+  "["
+  "]"
+  "{"
+  "}"
+] @punctuation.bracket
+
+[
+  ","
+  ":"
+  "::"
+] @punctuation.delimiter
+
+; Function definition - identifier after 'fn'
+(function_definition
+  (identifier) @function.definition)
+
+; Macro definition - identifier after 'macro'
+(macro_definition
+  (identifier) @function.macro)
+
+; Alias definition - identifier after 'alias'
+(alias_definition
+  (identifier) @function)
+
+; Test definition
+(test_definition
+  (string) @string.special)
+
+; Function parameters
+(parameter
+  (identifier) @variable.parameter)
+
+; Record fields
+(record_field
+  (identifier) @property)
+
+; Import
+(import_item
+  (identifier) @namespace)
+
+; Flags
+(long_flag) @attribute
+(short_flag) @attribute
+
+; Built-in commands
+(builtin_command) @function.builtin
+
+; User-defined command calls
+(command_expression
+  (command_name
+    (identifier) @function.call))
+
+; Match arms
+(match_arm
+  (_) @constant)
+
+; Range
+(range) @constant

queries/apx/locals.scm

@@ -0,0 +1,39 @@
+; ApX Tree-sitter locals queries for scope tracking
+
+; Scopes
+(function_definition) @local.scope
+(macro_definition) @local.scope
+(closure) @local.scope
+(for_statement) @local.scope
+(block) @local.scope
+
+; Definitions
+(assignment
+  (identifier) @local.definition)
+
+(variable_assignment
+  (variable) @local.definition)
+
+(parameter
+  (identifier) @local.definition)
+
+(function_definition
+  (identifier) @local.definition)
+
+(macro_definition
+  (identifier) @local.definition)
+
+(alias_definition
+  (identifier) @local.definition)
+
+(for_statement
+  (identifier) @local.definition)
+
+(closure_parameters
+  (identifier) @local.definition)
+
+; References
+(regular_variable) @local.reference
+(command_expression
+  (command_name
+    (identifier) @local.reference))