tree-sitter-hack.ebnf

//
// From tree-sitter-hack/src/grammar.json
//
//
// EBNF to generate railroad diagram at 
//      (IPV6) https://www.bottlecaps.de/rr/ui
//      (IPV4) https://rr.red-dove.com/ui
//

script ::=
	 '<\'?[hH][hH]? _statement*

identifier ::=
	 [a-zA-Z_\x80-\xff][a-zA-Z0-9_\x80-\xff]*

variable ::=
	 ( '$' [a-zA-Z_\x80-\xff][a-zA-Z0-9_\x80-\xff]* )

pipe_variable ::=
	 '$$'

_keyword ::=
	 'type'
	| 'newtype'
	| 'shape'
	| 'tuple'
	| 'clone'
	| 'new'
	| 'print'
	| 'namespace'
	| 'include'
	| 'include_once'
	| 'require'
	| 'require_once'
	| _primitive_type
	| _collection_type

qualified_identifier ::=
	 ( identifier | 'namespace' )? ( '\\'  identifier )+
	| identifier

scoped_identifier ::=
	 ( qualified_identifier | variable | scope_identifier | _xhp_identifier | pipe_variable ) '::' ( identifier | variable )

scope_identifier ::=
	 'self'
	| 'parent'
	| 'static'

_variablish ::=
	 variable
	| pipe_variable
	| list_expression
	| subscript_expression
	| qualified_identifier
	| parenthesized_expression
	| call_expression
	| scoped_identifier
	| scope_identifier
	| selection_expression
	| _xhp_identifier

_statement ::=
	 _declaration
	| module_attribute
	| compound_statement
	| empty_statement
	| expression_statement
	| return_statement
	| break_statement
	| continue_statement
	| throw_statement
	| echo_statement
	| unset_statement
	| use_statement
	| if_statement
	| while_statement
	| do_statement
	| for_statement
	| switch_statement
	| foreach_statement
	| try_statement
	| concurrent_statement
	| using_statement

_declaration ::=
	 function_declaration
	| class_declaration
	| interface_declaration
	| trait_declaration
	| alias_declaration
	| enum_declaration
	| abstract_enum_class_declaration
	| enum_class_declaration
	| namespace_declaration
	| const_declaration

module_attribute ::=
	 '<<' identifier ':' qualified_identifier arguments? ( ',' qualified_identifier arguments? )* ','? '>>'

heredoc ::=
	 '<<<' _heredoc_start _heredoc_start_newline? ( _heredoc_body | variable | embedded_braced_expression )* _heredoc_end_newline? _heredoc_end

embedded_braced_expression ::=
	 _embedded_opening_brace ( variable | call_expression | subscript_expression | selection_expression ) '}'

braced_expression ::=
	 '{' _expression '}'

_expression ::=
	 heredoc
	| array
	| tuple
	| shape
	| collection
	| _literal
	| _variablish
	| expression_tree
	| prefixed_string
	| parenthesized_expression
	| binary_expression
	| prefix_unary_expression
	| postfix_unary_expression
	| is_expression
	| as_expression
	| awaitable_expression
	| yield_expression
	| cast_expression
	| ternary_expression
	| lambda_expression
	| call_expression
	| selection_expression
	| new_expression
	| include_expression
	| require_expression
	| anonymous_function_expression
	| xhp_expression
	| function_pointer
	| enum_class_label

empty_statement ::=
	 ';'

expression_statement ::=
	 _expression ';'

compound_statement ::=
	 '{' _statement* '}'

return_statement ::=
	 'return' _expression? ';'

break_statement ::=
	 'break' _expression? ';'

continue_statement ::=
	 'continue' _expression? ';'

throw_statement ::=
	 'throw' _expression ';'

echo_statement ::=
	 'echo' _expression ( ',' _expression )* ';'

unset_statement ::=
	 'unset' '(' ( _variablish ( ',' _variablish )* )? ')' ';'

concurrent_statement ::=
	 'concurrent' compound_statement

use_statement ::=
	 'use' ( use_clause ( ',' use_clause )* ','? | use_type? _namespace_identifier '{' use_clause ( ',' use_clause )* ','? '}' ) ';'

use_type ::=
	 'namespace'
	| 'function'
	| 'type'
	| 'const'

use_clause ::=
	 use_type? _namespace_identifier ( 'as' identifier )?

_namespace_identifier ::=
	 qualified_identifier '\\' ?
	| '\\' 

if_statement ::=
	 'if' parenthesized_expression _statement ( ( 'elseif' | 'else' 'if' ) parenthesized_expression _statement )* ( 'else' _statement )?

switch_statement ::=
	 'switch' parenthesized_expression '{' ( switch_case | switch_default )* '}'

switch_case ::=
	 'case' _expression ':' _statement*

switch_default ::=
	 'default' ':' _statement*

foreach_statement ::=
	 'foreach' '(' _expression await_modifier? 'as' ( _variablish '=>' )? _variablish ')' _statement

while_statement ::=
	 'while' parenthesized_expression _statement

do_statement ::=
	 'do' _statement 'while' parenthesized_expression ';'

for_statement ::=
	 'for' '(' ( _expression ( ',' _expression )* )? ';' ( _expression ( ',' _expression )* )? ';' ( _expression ( ',' _expression )* )? ')' _statement

try_statement ::=
	 'try' compound_statement catch_clause* ( catch_clause | finally_clause )

catch_clause ::=
	 'catch' '(' _type variable ')' compound_statement

finally_clause ::=
	 'finally' compound_statement

using_statement ::=
	 await_modifier? 'using' ( expression_statement | '(' _expression ( ',' _expression )* ')' ( compound_statement | ';' ) )

_literal ::=
	 string
	| integer
	| float
	| true
	| false
	| null

float ::=
	 ( [0-9]+'.'[0-9]*([eE][+-]?[0-9]+)? | [0-9]*'.'[0-9]+([eE][+-]?[0-9]+)? | [0-9]+[eE][+-]?[0-9]+ )

integer ::=
	 ( [1-9][0-9]* | '0'[0-7]* | '0'[xX][0-9a-fA-F]+ | '0'[bB][01]+ )

true ::=
	 'true'
	| 'True'
	| 'TRUE'

false ::=
	 'false'
	| 'False'
	| 'FALSE'

null ::=
	 'null'
	| 'Null'
	| 'NULL'

string ::=
	 ( "'"("\'"|"\\"|"\"?[^'\])*"'" | '"'('\"'|'\\'|'\'?[^"\])*'"' )

expression_tree ::=
	 identifier '`'[^`]*'`'

prefixed_string ::=
	 identifier string

_type ::=
	 type_specifier
	| type_constant
	| shape_type_specifier
	| function_type_specifier
	| tuple_type_specifier

type_specifier ::=
	 _type_modifier* ( _primitive_type | qualified_identifier | _collection_type | _xhp_identifier ) type_arguments?

_type_modifier ::=
	 '@'
	| '?'
	| '~'

tuple_type_specifier ::=
	 _type_modifier* '(' _type ( ',' _type )* ','? ')'

function_type_specifier ::=
	 _type_modifier* '(' 'function' [ #x09#x0A#x0B#x0C#x0D]* '(' ( inout_modifier? _type variadic_modifier? ( ',' inout_modifier? _type variadic_modifier? )* ','? )? ')' capability_list? ':' _type ')'

shape_type_specifier ::=
	 _type_modifier* 'shape' '(' ( ( field_specifier | '...' ) ( ',' ( field_specifier | '...' ) )* ','? )? ')'

field_specifier ::=
	 '?'? _expression '=>' _type

type_constant ::=
	 _type_modifier* _type_constant

_type_constant ::=
	 ( qualified_identifier | _type_constant ) '::' identifier

_collection_type ::=
	 'array'
	| 'varray'
	| 'darray'
	| 'vec'
	| 'dict'
	| 'keyset'

_primitive_type ::=
	 'bool'
	| 'float'
	| 'int'
	| 'num'
	| 'string'
	| 'arraykey'
	| 'void'
	| 'nonnull'
	| null
	| 'mixed'
	| 'dynamic'
	| 'noreturn'
	| 'nothing'
	| 'resource'

type_arguments ::=
	 '<' ( _type ( ',' _type )* ','? )? '>'

type_parameters ::=
	 '<' type_parameter ( ',' type_parameter )* ','? '>'

type_parameter ::=
	 attribute_modifier? ( '+' | '-' | 'reify' )? identifier ( ( 'as' | 'super' ) _type )*

where_clause ::=
	 'where' ( where_constraint ','? )+

where_constraint ::=
	 _type ( 'as' | 'super' | '=' ) _type

array ::=
	 _collection_type type_arguments? '[' ( ( _expression | element_initializer ) ( ',' ( _expression | element_initializer ) )* ','? )? ']'

element_initializer ::=
	 _expression '=>' _expression

tuple ::=
	 'tuple' '(' ( _expression ( ',' _expression )* ','? )? ')'

shape ::=
	 'shape' '(' ( field_initializer ( ',' field_initializer )* ','? )? ')'

field_initializer ::=
	 ( string | scoped_identifier ) '=>' _expression

collection ::=
	 qualified_identifier type_arguments? '{' ( ( _expression | element_initializer ) ( ',' ( _expression | element_initializer ) )* ','? )? '}'

include_expression ::=
	 ( 'include' | 'include_once' ) _expression

require_expression ::=
	 ( 'require' | 'require_once' ) _expression

parenthesized_expression ::=
	 '(' _expression ')'

subscript_expression ::=
	 _expression '[' _expression? ']'

list_expression ::=
	 'list' '(' _expression? ( ',' _expression? )* ','? ')'

binary_expression ::=
	 _expression '|>' _expression
	| _expression '??' _expression
	| _expression '||' _expression
	| _expression '&&' _expression
	| _expression '|' _expression
	| _expression '^' _expression
	| _expression '&' _expression
	| _expression '==' _expression
	| _expression '!=' _expression
	| _expression '===' _expression
	| _expression '!==' _expression
	| _expression '<' _expression
	| _expression '>' _expression
	| _expression '<=' _expression
	| _expression '>=' _expression
	| _expression '<=>' _expression
	| _expression '<<' _expression
	| _expression '>>' _expression
	| _expression '+' _expression
	| _expression '-' _expression
	| _expression '.' _expression
	| _expression '*' _expression
	| _expression '/' _expression
	| _expression '%' _expression
	| _expression '**' _expression
	| _expression '?:' _expression
	| _expression '=' _expression
	| _expression '??=' _expression
	| _expression '.=' _expression
	| _expression '|=' _expression
	| _expression '^=' _expression
	| _expression '&=' _expression
	| _expression '<<=' _expression
	| _expression '>>=' _expression
	| _expression '+=' _expression
	| _expression '-=' _expression
	| _expression '*=' _expression
	| _expression '/=' _expression
	| _expression '%=' _expression
	| _expression '**=' _expression

prefix_unary_expression ::=
	 '!' _expression
	| '~' _expression
	| '-' _expression
	| '+' _expression
	| '++' _expression
	| '--' _expression
	| 'print' _expression
	| 'clone' _expression
	| 'await' _expression
	| '@' _expression

postfix_unary_expression ::=
	 _expression ( '++' | '--' )

is_expression ::=
	 _expression 'is' _type

as_expression ::=
	 _expression ( 'as' | '?as' ) _type

awaitable_expression ::=
	 'async' compound_statement

yield_expression ::=
	 'yield' ( _expression | element_initializer )

cast_expression ::=
	 '(' ( 'array' | 'int' | 'float' | 'string' | 'bool' ) ')' _expression

ternary_expression ::=
	 _expression '?' _expression ':' _expression

lambda_expression ::=
	 attribute_modifier? async_modifier? ( _single_parameter_parameters | parameters capability_list? ( ':' _type )? ) '==>' ( _expression | compound_statement )

_single_parameter_parameters ::=
	 _single_parameter

_single_parameter ::=
	 variable

call_expression ::=
	 ( _expression | _collection_type ) type_arguments? arguments

new_expression ::=
	 'new' _variablish type_arguments? arguments

arguments ::=
	 '(' ( argument ( ',' argument )* ','? )? ')'

argument ::=
	 ( inout_modifier | variadic_modifier )? _expression

selection_expression ::=
	 ( _variablish | as_expression ) ( '?->' | '->' ) ( _variablish | braced_expression | _keyword )

alias_declaration ::=
	 attribute_modifier? ( 'type' | 'newtype' ) identifier type_parameters? ( 'as' _type )? '=' _type ';'

function_declaration ::=
	 attribute_modifier? _function_declaration_header ( compound_statement | ';' )

_function_declaration_header ::=
	 async_modifier? 'function' identifier type_parameters? parameters capability_list? ( ':' attribute_modifier? _type )? where_clause?

capability_list ::=
	 '[' ( capability ( ',' capability )* )? ']'

capability ::=
	 identifier type_parameters?
	| scoped_identifier
	| 'ctx' variable

parameters ::=
	 '(' ( variadic_modifier | parameter ( ',' parameter )* ','? )? ')'

parameter ::=
	 attribute_modifier? visibility_modifier? inout_modifier? _type? variadic_modifier? variable ( '=' _expression )?

trait_declaration ::=
	 attribute_modifier? 'trait' identifier type_parameters? implements_clause? where_clause? member_declarations

interface_declaration ::=
	 attribute_modifier? 'interface' identifier type_parameters? extends_clause? where_clause? member_declarations

class_declaration ::=
	 attribute_modifier? _class_modifier? _class_modifier? xhp_modifier? 'class' ( identifier | _xhp_identifier ) type_parameters? extends_clause? implements_clause? where_clause? member_declarations

member_declarations ::=
	 '{' ( _class_const_declaration | method_declaration | property_declaration | type_const_declaration | context_const_declaration | trait_use_clause | require_implements_clause | require_extends_clause | xhp_attribute_declaration | xhp_children_declaration | xhp_category_declaration )* '}'

trait_use_clause ::=
	 'use' _type ( ',' _type )* ( '{' ( ( trait_select_clause | trait_alias_clause ) ';' )* '}' | ';' )

trait_select_clause ::=
	 qualified_identifier '::' identifier 'insteadof' qualified_identifier ( ',' qualified_identifier )*

trait_alias_clause ::=
	 identifier 'as' ( visibility_modifier identifier? | visibility_modifier? identifier )

extends_clause ::=
	 'extends' _type ( ',' _type )*

implements_clause ::=
	 'implements' _type ( ',' _type )*

require_extends_clause ::=
	 'require' 'extends' _type ( ',' _type )* ';'

require_implements_clause ::=
	 'require' 'implements' _type ( ',' _type )* ';'

method_declaration ::=
	 attribute_modifier? _member_modifier* _function_declaration_header ( compound_statement | ';' )

_class_const_declaration ::=
	 _member_modifier* 'const' _type? _class_const_declarator ( ',' _class_const_declarator )* ';'

_class_const_declarator ::=
	 ( identifier | _keyword ) ( '=' _expression )?

type_const_declaration ::=
	 attribute_modifier? _member_modifier* 'const' 'type' identifier type_parameters? ( 'as' _type )? ( '=' _type )? ';'

context_const_declaration ::=
	 abstract_modifier? 'const' 'ctx' identifier ( 'super' capability_list )? ( 'as' capability_list )? ( '=' capability_list )? ';'

const_declaration ::=
	 'const' _type? const_declarator ( ',' const_declarator )* ';'

const_declarator ::=
	 ( identifier | _keyword ) ( '=' _expression )

property_declaration ::=
	 attribute_modifier? _member_modifier* _type? property_declarator ( ',' property_declarator )* ';'

property_declarator ::=
	 variable ( '=' _expression )?

enum_declaration ::=
	 attribute_modifier? 'enum' identifier ':' _type ( 'as' _type )? '{' enumerator* '}'

abstract_enum_class_declaration ::=
	 attribute_modifier? 'abstract' 'enum' 'class' identifier ':' extends_clause? _type '{' ( typed_enumerator | 'abstract' _type identifier ';' )* '}'

enum_class_declaration ::=
	 attribute_modifier? 'enum' 'class' identifier ':' _type extends_clause? '{' typed_enumerator* '}'

enum_class_label ::=
	 qualified_identifier? '#' identifier

enumerator ::=
	 identifier '=' _expression ';'

typed_enumerator ::=
	 _type enumerator

namespace_declaration ::=
	 'namespace' ( qualified_identifier ';' | qualified_identifier? compound_statement )?

_member_modifier ::=
	 visibility_modifier
	| static_modifier
	| abstract_modifier
	| final_modifier

_class_modifier ::=
	 abstract_modifier
	| final_modifier

final_modifier ::=
	 'final'

abstract_modifier ::=
	 'abstract'

xhp_modifier ::=
	 'xhp'

static_modifier ::=
	 'static'

visibility_modifier ::=
	 'public'
	| 'protected'
	| 'private'

attribute_modifier ::=
	 '<<' qualified_identifier arguments? ( ',' qualified_identifier arguments? )* ','? '>>'

inout_modifier ::=
	 'inout'

variadic_modifier ::=
	 '...'

async_modifier ::=
	 'async'

await_modifier ::=
	 'await'

xhp_identifier ::=
	 [a-zA-Z_][a-zA-Z0-9_]*([-:][a-zA-Z0-9_]+)*

xhp_class_identifier ::=
	 ':'[a-zA-Z_][a-zA-Z0-9_]*([-:][a-zA-Z0-9_]+)*

_xhp_identifier ::=
	 xhp_identifier
	| xhp_class_identifier

xhp_category_identifier ::=
	 '%'[a-zA-Z_][a-zA-Z0-9_]*([-:][a-zA-Z0-9_]+)*

xhp_expression ::=
	 xhp_open_close
	| xhp_open ( xhp_string | xhp_comment | braced_expression | xhp_expression )* xhp_close

xhp_comment ::=
	 ( '<!--' ('-'?'>')?([^>]|[^-]'>'|[^-]'->')* '-->' )

xhp_string ::=
	 [^<{]+

xhp_open ::=
	 '<' _xhp_identifier xhp_attribute* '>'

xhp_open_close ::=
	 '<' _xhp_identifier xhp_attribute* '/>'

xhp_close ::=
	 '</' _xhp_identifier '>'

xhp_attribute ::=
	 xhp_identifier '=' ( string | braced_expression )
	| braced_expression
	| xhp_spread_expression

xhp_spread_expression ::=
	 '{' '...' _expression '}'

xhp_attribute_declaration ::=
	 'attribute' xhp_class_attribute ( ',' xhp_class_attribute )* ';'

xhp_class_attribute ::=
	 ( _type | xhp_enum_type ) xhp_identifier? ( '=' _expression )? ( '@required' | '@lateinit' )?

xhp_enum_type ::=
	 'enum' '{' ( string | integer ) ( ',' ( string | integer ) )* ','? '}'

_xhp_attribute_expression ::=
	 xhp_identifier
	| xhp_class_identifier
	| xhp_category_identifier
	| _xhp_binary_expression
	| _xhp_postfix_unary_expression
	| _xhp_parenthesized_expression

function_pointer ::=
	 ( scoped_identifier | qualified_identifier ) type_arguments

comment ::=
	 ( '//' '.'* | '/*' [^*]*'\'*+([^/*][^*]*'\'*+)* '/' )

anonymous_function_expression ::=
	 async_modifier? 'function' parameters capability_list? ( ':' _type )? _anonymous_function_use_clause? compound_statement

_anonymous_function_use_clause ::=
	 'use' '(' variable ( ',' variable )* ','? ')'

xhp_children_declaration ::=
	 'children' _xhp_attribute_expression ( ',' _xhp_attribute_expression )* ';'

xhp_category_declaration ::=
	 'category' xhp_category_identifier ( ',' xhp_category_identifier )* ';'

_xhp_binary_expression ::=
	 _xhp_attribute_expression '|' _xhp_attribute_expression

_xhp_postfix_unary_expression ::=
	 _xhp_attribute_expression ( '+' | '*' | '?' )

_xhp_parenthesized_expression ::=
	 '(' _xhp_attribute_expression ( ',' _xhp_attribute_expression )* ')'