tree-sitter-fortran.ebnf

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

translation_unit ::=
	 _top_level_item* program?

_top_level_item ::=
	 include_statement _end_of_statement | program | module | submodule | interface | subroutine | function

program ::=
	 program_statement? _specification_part* _statement* internal_procedures? end_program_statement

program_statement ::=
	 [pP][rR][oO][gG][rR][aA][mM] _name

end_program_statement ::=
	 ( [eE][nN][dD] [pP][rR][oO][gG][rR][aA][mM]? | [eE][nN][dD][pP][rR][oO][gG][rR][aA][mM] ) _name? _end_of_statement

module ::=
	 module_statement _specification_part* internal_procedures? end_module_statement

module_statement ::=
	 [mM][oO][dD][uU][lL][eE] _name

end_module_statement ::=
	 ( [eE][nN][dD] [mM][oO][dD][uU][lL][eE]? | [eE][nN][dD][mM][oO][dD][uU][lL][eE] ) _name? _end_of_statement

submodule ::=
	 submodule_statement _specification_part* internal_procedures? end_submodule_statement

submodule_statement ::=
	 [sS][uU][bB][mM][oO][dD][uU][lL][eE] '(' module_name ( ':' module_name )? ')' _name

end_submodule_statement ::=
	 ( [eE][nN][dD] [sS][uU][bB][mM][oO][dD][uU][lL][eE]? | [eE][nN][dD][sS][uU][bB][mM][oO][dD][uU][lL][eE] ) _name? _end_of_statement

module_name ::=
	 _name

interface ::=
	 interface_statement ( import_statement | procedure_statement | function | subroutine )* end_interface_statement

interface_statement ::=
	 abstract_specifier? [iI][nN][tT][eE][rR][fF][aA][cC][eE] ( _name | _generic_procedure )?

end_interface_statement ::=
	 ( [eE][nN][dD] [iI][nN][tT][eE][rR][fF][aA][cC][eE] | [eE][nN][dD][iI][nN][tT][eE][rR][fF][aA][cC][eE] ) ( _name | _generic_procedure )? _end_of_statement

assignment ::=
	 [aA][sS][sS][iI][gG][nN][mM][eE][nN][tT] '(' '=' ')'

operator ::=
	 [oO][pP][eE][rR][aA][tT][oO][rR] '(' [^()]+ ')'

defined_io_procedure ::=
	 ( [rR][eE][aA][dD] | [wW][rR][iI][tT][eE] ) '(' ( [fF][oO][rR][mM][aA][tT][tT][eE][dD] | [uU][nN][fF][oO][rR][mM][aA][tT][tT][eE][dD] ) ')'

_generic_procedure ::=
	 assignment
	| operator
	| defined_io_procedure

subroutine ::=
	 subroutine_statement _end_of_statement _specification_part* _statement* internal_procedures? end_subroutine_statement

subroutine_statement ::=
	 _callable_interface_qualifers? [sS][uU][bB][rR][oO][uU][tT][iI][nN][eE] _name _parameters? language_binding?

end_subroutine_statement ::=
	 ( [eE][nN][dD] [sS][uU][bB][rR][oO][uU][tT][iI][nN][eE]? | [eE][nN][dD][sS][uU][bB][rR][oO][uU][tT][iI][nN][eE] ) _name? _end_of_statement

module_procedure ::=
	 module_procedure_statement _end_of_statement _specification_part* _statement* internal_procedures? end_module_procedure_statement

module_procedure_statement ::=
	 _callable_interface_qualifers? [mM][oO][dD][uU][lL][eE] [pP][rR][oO][cC][eE][dD][uU][rR][eE] _name

end_module_procedure_statement ::=
	 ( [eE][nN][dD] [pP][rR][oO][cC][eE][dD][uU][rR][eE]? | [eE][nN][dD][pP][rR][oO][cC][eE][dD][uU][rR][eE] ) _name? _end_of_statement

function ::=
	 function_statement _end_of_statement _specification_part* _statement* internal_procedures? end_function_statement

function_statement ::=
	 _callable_interface_qualifers? [fF][uU][nN][cC][tT][iI][oO][nN] _name _parameters? ( language_binding | function_result )*?

language_binding ::=
	 [bB][iI][nN][dD] '(' identifier ( ',' keyword_argument )? ')'

_callable_interface_qualifers ::=
	 procedure_attributes | procedure_qualifier | _intrinsic_type | derived_type+

procedure_attributes ::=
	 [aA][tT][tT][rR][iI][bB][uU][tT][eE][sS] '(' ( [gG][lL][oO][bB][aA][lL] | [dD][eE][vV][iI][cC][eE] | [hH][oO][sS][tT] | [gG][rR][iI][dD]'_'[gG][lL][oO][bB][aA][lL] ) ( ',' ( [gG][lL][oO][bB][aA][lL] | [dD][eE][vV][iI][cC][eE] | [hH][oO][sS][tT] | [gG][rR][iI][dD]'_'[gG][lL][oO][bB][aA][lL] ) )* ')'

end_function_statement ::=
	 ( [eE][nN][dD] [fF][uU][nN][cC][tT][iI][oO][nN]? | [eE][nN][dD][fF][uU][nN][cC][tT][iI][oO][nN] ) _name? _end_of_statement

function_result ::=
	 [rR][eE][sS][uU][lL][tT] '(' identifier ')'

_name ::=
	 identifier

_parameters ::=
	 '(' ')'
	| parameters

parameters ::=
	 '(' identifier ( ',' identifier )* ')'

internal_procedures ::=
	 contains_statement _end_of_statement ( function | module_procedure | subroutine )*

contains_statement ::=
	 [cC][oO][nN][tT][aA][iI][nN][sS]

_specification_part ::=
	 include_statement _end_of_statement | use_statement _end_of_statement | implicit_statement _end_of_statement | save_statement _end_of_statement | import_statement _end_of_statement | public_statement _end_of_statement | private_statement _end_of_statement | enum | interface | derived_type_definition | namelist_statement _end_of_statement | common_statement _end_of_statement | variable_declaration _end_of_statement | variable_modification _end_of_statement | parameter_statement _end_of_statement | equivalence_statement _end_of_statement | data_statement _end_of_statement | statement_label format_statement _end_of_statement

use_statement ::=
	 [uU][sS][eE] ( ',' ( [iI][nN][tT][rR][iI][nN][sS][iI][cC] | [nN][oO][nN]'_'[iI][nN][tT][rR][iI][nN][sS][iI][cC] ) '::' | '::' ) identifier ( ',' use_alias ( ',' use_alias )* | included_items )?

included_items ::=
	 ',' [oO][nN][lL][yY] ':' ( ( use_alias | identifier | _generic_procedure ) ( ',' ( use_alias | identifier | _generic_procedure ) )* )?

use_alias ::=
	 identifier '=>' identifier

implicit_statement ::=
	 [iI][mM][pP][lL][iI][cC][iI][tT] ( intrinsic_type size? '(' implicit_range ( ',' implicit_range )* ')' ( ',' intrinsic_type size? '(' implicit_range ( ',' implicit_range )* ')' )* | [nN][oO][nN][eE] ( '(' ( [tT][yY][pP][eE] | [eE][xX][tT][eE][rR][nN][aA][lL] ) ( ',' ( [tT][yY][pP][eE] | [eE][xX][tT][eE][rR][nN][aA][lL] ) )* ')' )? )

save_statement ::=
	 [sS][aA][vV][eE] ( '::'? ( identifier | '/' identifier '/' ) ( ',' ( identifier | '/' identifier '/' ) )* )?

private_statement ::=
	 [pP][rR][iI][vV][aA][tT][eE] ( '::' ( identifier | _generic_procedure ) ( ',' ( identifier | _generic_procedure ) )* )?

public_statement ::=
	 [pP][uU][bB][lL][iI][cC] ( '::' ( identifier | _generic_procedure ) ( ',' ( identifier | _generic_procedure ) )* )?

namelist_statement ::=
	 [nN][aA][mM][eE][lL][iI][sS][tT] variable_group+

common_statement ::=
	 [cC][oO][mM][mM][oO][nN] ( variable_group | identifier ( ',' identifier )* )+

variable_group ::=
	 '/' _name '/' identifier ( ',' identifier )*

implicit_range ::=
	 [a-zA-Z] ( '-' [a-zA-Z] )?

import_statement ::=
	 [iI][mM][pP][oO][rR][tT] _import_names?

_import_names ::=
	 '::'? identifier ( ',' identifier )*
	| ',' ( [oO][nN][lL][yY] ':' identifier ( ',' identifier )* | [nN][oO][nN][eE] | [aA][lL][lL] )

derived_type_definition ::=
	 derived_type_statement public_statement? private_statement? ( [sS][eE][qQ][uU][eE][nN][cC][eE] _end_of_statement )? ( ( include_statement | variable_declaration ) _end_of_statement )* derived_type_procedures? end_type_statement

abstract_specifier ::=
	 [aA][bB][sS][tT][rR][aA][cC][tT]

access_specifier ::=
	 [pP][uU][bB][lL][iI][cC]
	| [pP][rR][iI][vV][aA][tT][eE]

base_type_specifier ::=
	 [eE][xX][tT][eE][nN][dD][sS] '(' identifier ')'

_derived_type_qualifier ::=
	 abstract_specifier
	| access_specifier
	| base_type_specifier
	| language_binding

derived_type_statement ::=
	 statement_label? [tT][yY][pP][eE] ( '::'? _type_name | ',' _derived_type_qualifier ( ',' _derived_type_qualifier )* '::' _type_name ) _end_of_statement

end_type_statement ::=
	 ( [eE][nN][dD] [tT][yY][pP][eE]? | [eE][nN][dD][tT][yY][pP][eE] ) _name? _end_of_statement

_type_name ::=
	 identifier

derived_type_procedures ::=
	 contains_statement public_statement? private_statement? procedure_statement*

procedure_statement ::=
	 _procedure_kind ( '(' identifier ')' )? ( ',' procedure_attribute ( ',' procedure_attribute )* )? '::'? ( method_name | binding_name '=>' method_name ) ( ',' ( method_name | binding_name '=>' method_name ) )*

binding_name ::=
	 identifier
	| _generic_procedure

method_name ::=
	 identifier

_procedure_kind ::=
	 [gG][eE][nN][eE][rR][iI][cC]
	| [iI][nN][iI][tT][iI][aA][lL]
	| [pP][rR][oO][cC][eE][dD][uU][rR][eE]
	| [mM][oO][dD][uU][lL][eE] [pP][rR][oO][cC][eE][dD][uU][rR][eE]
	| [pP][rR][oO][pP][eE][rR][tT][yY]
	| [fF][iI][nN][aA][lL]

procedure_attribute ::=
	 [dD][eE][fF][eE][rR][rR][eE][dD] | [pP][aA][sS][sS] ( '(' identifier ')' )? | [nN][oO][pP][aA][sS][sS] | [nN][oO][nN]'_'[oO][vV][eE][rR][rR][iI][dD][aA][bB][lL][eE] | [pP][uU][bB][lL][iI][cC] | [pP][rR][iI][vV][aA][tT][eE] | [fF][aA][mM][iI][lL][yY] | [pP][oO][iI][nN][tT][eE][rR]

variable_declaration ::=
	 ( _intrinsic_type | derived_type | procedure_declaration ) ( ',' type_qualifier ( ',' type_qualifier )* )? '::'? _declaration_targets

procedure_declaration ::=
	 [pP][rR][oO][cC][eE][dD][uU][rR][eE] ( '(' identifier? ')' )? ( ',' procedure_attribute ( ',' procedure_attribute )* )?

variable_modification ::=
	 ( type_qualifier | variable_attributes )+ '::'? _declaration_targets

variable_attributes ::=
	 [aA][tT][tT][rR][iI][bB][uU][tT][eE][sS] '(' ( [dD][eE][vV][iI][cC][eE] | [mM][aA][nN][aA][gG][eE][dD] | [cC][oO][nN][sS][tT][aA][nN][tT] | [sS][hH][aA][rR][eE][dD] | [pP][iI][nN][nN][eE][dD] | [tT][eE][xX][tT][uU][rR][eE] ) ')'

_declaration_targets ::=
	 ( identifier | identifier character_length | call_expression | assignment_statement | pointer_association_statement ) ( ',' ( identifier | identifier character_length | call_expression | assignment_statement | pointer_association_statement ) )*

_intrinsic_type ::=
	 intrinsic_type size?

intrinsic_type ::=
	 [bB][yY][tT][eE]
	| [iI][nN][tT][eE][gG][eE][rR]
	| [rR][eE][aA][lL]
	| ( [dD][oO][uU][bB][lL][eE] [pP][rR][eE][cC][iI][sS][iI][oO][nN] | [dD][oO][uU][bB][lL][eE][pP][rR][eE][cC][iI][sS][iI][oO][nN] )
	| [cC][oO][mM][pP][lL][eE][xX]
	| ( [dD][oO][uU][bB][lL][eE] [cC][oO][mM][pP][lL][eE][xX] | [dD][oO][uU][bB][lL][eE][cC][oO][mM][pP][lL][eE][xX] )
	| [lL][oO][gG][iI][cC][aA][lL]
	| [cC][hH][aA][rR][aA][cC][tT][eE][rR]

derived_type ::=
	 ( [tT][yY][pP][eE] | [cC][lL][aA][sS][sS] ) '(' ( _intrinsic_type | _type_name | unlimited_polymorphic ) ')'

unlimited_polymorphic ::=
	 '*'

size ::=
	 '*'? argument_list
	| '*' ( [0-9]+ | parenthesized_expression )

character_length ::=
	 '*' [0-9]+? ( '(' '*' ')' )?

type_qualifier ::=
	 [aA][bB][sS][tT][rR][aA][cC][tT]
	| [aA][lL][lL][oO][cC][aA][tT][aA][bB][lL][eE]
	| [aA][uU][tT][oO][mM][aA][tT][iI][cC]
	| [dD][iI][mM][eE][nN][sS][iI][oO][nN] argument_list?
	| [cC][oO][nN][sS][tT][aA][nN][tT]
	| [cC][oO][nN][tT][iI][gG][uU][oO][uU][sS]
	| [dD][eE][vV][iI][cC][eE]
	| [eE][xX][tT][eE][rR][nN][aA][lL]
	| [iI][nN][tT][eE][nN][tT] '(' ( [iI][nN] | [oO][uU][tT] | ( [iI][nN] [oO][uU][tT] | [iI][nN][oO][uU][tT] ) ) ')'
	| [iI][nN][tT][rR][iI][nN][sS][iI][cC]
	| [mM][aA][nN][aA][gG][eE][dD]
	| [oO][pP][tT][iI][oO][nN][aA][lL]
	| [pP][aA][rR][aA][mM][eE][tT][eE][rR]
	| [pP][iI][nN][nN][eE][dD]
	| [pP][oO][iI][nN][tT][eE][rR]
	| [pP][rR][iI][vV][aA][tT][eE]
	| [pP][rR][oO][tT][eE][cC][tT][eE][dD]
	| [pP][uU][bB][lL][iI][cC]
	| [sS][aA][vV][eE]
	| [sS][eE][qQ][uU][eE][nN][cC][eE]
	| [sS][hH][aA][rR][eE][dD]
	| [sS][tT][aA][tT][iI][cC]
	| [tT][aA][rR][gG][eE][tT]
	| [tT][eE][xX][tT][uU][rR][eE]
	| [vV][aA][lL][uU][eE]
	| [vV][oO][lL][aA][tT][iI][lL][eE]

procedure_qualifier ::=
	 [eE][lL][eE][mM][eE][nN][tT][aA][lL]
	| [iI][mM][pP][uU][rR][eE]
	| [mM][oO][dD][uU][lL][eE]
	| [pP][uU][rR][eE]
	| [rR][eE][cC][uU][rR][sS][iI][vV][eE]

parameter_statement ::=
	 [pP][aA][rR][aA][mM][eE][tT][eE][rR] '(' parameter_assignment ( ',' parameter_assignment )* ')'

parameter_assignment ::=
	 identifier '=' _expression

equivalence_statement ::=
	 [eE][qQ][uU][iI][vV][aA][lL][eE][nN][cC][eE] equivalence_set ( ',' equivalence_set )*

equivalence_set ::=
	 '(' ( identifier | call_expression ) ',' ( identifier | call_expression ) ( ',' ( identifier | call_expression ) )* ')'

_statement ::=
	 statement_label? _statements _end_of_statement

_statements ::=
	 assignment_statement
	| pointer_association_statement
	| call_expression
	| subroutine_call
	| keyword_statement
	| include_statement
	| if_statement
	| arithmetic_if_statement
	| where_statement
	| forall_statement
	| select_case_statement
	| select_type_statement
	| select_rank_statement
	| do_loop_statement
	| do_label_statement
	| format_statement
	| open_statement
	| close_statement
	| print_statement
	| write_statement
	| read_statement
	| inquire_statement
	| stop_statement
	| block_construct
	| associate_statement
	| file_position_statement

statement_label ::=
	 _integer_literal

statement_label_reference ::=
	 statement_label

stop_statement ::=
	 [eE][rR][rR][oO][rR]? [sS][tT][oO][pP] _expression? ( ',' [qQ][uU][iI][eE][tT] '=' _expression )?

assignment_statement ::=
	 _expression '=' _expression

pointer_association_statement ::=
	 _expression '=>' _expression

subroutine_call ::=
	 [cC][aA][lL][lL] _expression cuda_kernel_argument_list? argument_list?

cuda_kernel_argument_list ::=
	 '<<<' _expression ( ',' _expression )* '>>>'

keyword_statement ::=
	 [cC][oO][nN][tT][iI][nN][uU][eE]
	| [cC][yY][cC][lL][eE] identifier?
	| [eE][xX][iI][tT] identifier?
	| ( [gG][oO] [tT][oO] | [gG][oO][tT][oO] ) ( statement_label_reference | '(' statement_label_reference ( ',' statement_label_reference )* ')' ','? _expression )
	| [rR][eE][tT][uU][rR][nN]

include_statement ::=
	 [iI][nN][cC][lL][uU][dD][eE] string_literal

data_statement ::=
	 [dD][aA][tT][aA] data_set ( ',' data_set )*

data_set ::=
	 ( identifier | implied_do_loop_expression | call_expression | derived_type_member_expression ) ( ',' ( identifier | implied_do_loop_expression | call_expression | derived_type_member_expression ) )* data_value

data_value ::=
	 '/' number_literal '*'? ( number_literal | complex_literal | string_literal | boolean_literal | unary_expression | null_literal | identifier | call_expression ) ( ',' number_literal '*'? ( number_literal | complex_literal | string_literal | boolean_literal | unary_expression | null_literal | identifier | call_expression ) )* '/'

do_loop_statement ::=
	 block_label_start_expression? [dD][oO] ','? ( while_statement | loop_control_expression | concurrent_statement )? _end_of_statement _statement* statement_label? end_do_loop_statement

do_label_statement ::=
	 [dD][oO] statement_label_reference ','? loop_control_expression

end_do_loop_statement ::=
	 ( [eE][nN][dD] [dD][oO] | [eE][nN][dD][dD][oO] ) _block_label?

while_statement ::=
	 [wW][hH][iI][lL][eE] parenthesized_expression

concurrent_statement ::=
	 concurrent_header concurrent_locality*

concurrent_header ::=
	 [cC][oO][nN][cC][uU][rR][rR][eE][nN][tT] '(' ( _intrinsic_type '::' )? concurrent_control ( ',' concurrent_control )* ( ',' _expression )? ')'

concurrent_control ::=
	 identifier '=' _expression ':' _expression ( ':' _expression )?

concurrent_locality ::=
	 ( [lL][oO][cC][aA][lL] | [lL][oO][cC][aA][lL]'_'[iI][nN][iI][tT] | [sS][hH][aA][rR][eE][dD] ) '(' identifier ( ',' identifier )* ')'
	| [dD][eE][fF][aA][uU][lL][tT] '(' [nN][oO][nN][eE] ')'

if_statement ::=
	 _inline_if_statement
	| _block_if_statement

_inline_if_statement ::=
	 [iI][fF] parenthesized_expression _statements

arithmetic_if_statement ::=
	 [iI][fF] parenthesized_expression statement_label_reference ',' statement_label_reference ',' statement_label_reference

_block_if_statement ::=
	 block_label_start_expression? [iI][fF] parenthesized_expression [tT][hH][eE][nN] _block_label? _end_of_statement _statement* elseif_clause* else_clause? statement_label? end_if_statement

end_if_statement ::=
	 ( [eE][nN][dD] [iI][fF] | [eE][nN][dD][iI][fF] ) _block_label?

elseif_clause ::=
	 ( [eE][lL][sS][eE] [iI][fF] | [eE][lL][sS][eE][iI][fF] ) parenthesized_expression [tT][hH][eE][nN] _block_label? _end_of_statement _statement*

else_clause ::=
	 [eE][lL][sS][eE] _block_label? _end_of_statement _statement*

where_statement ::=
	 _inline_where_statement
	| _block_where_statement

_inline_where_statement ::=
	 [wW][hH][eE][rR][eE] parenthesized_expression _statements

_block_where_statement ::=
	 block_label_start_expression? [wW][hH][eE][rR][eE] parenthesized_expression _end_of_statement _statement* elsewhere_clause* end_where_statement

end_where_statement ::=
	 ( [eE][nN][dD] [wW][hH][eE][rR][eE] | [eE][nN][dD][wW][hH][eE][rR][eE] ) _block_label?

elsewhere_clause ::=
	 ( [eE][lL][sS][eE] [wW][hH][eE][rR][eE] | [eE][lL][sS][eE][wW][hH][eE][rR][eE] ) parenthesized_expression? _block_label? _end_of_statement _statement*

forall_statement ::=
	 _inline_forall_statement
	| _block_forall_statement

triplet_spec ::=
	 identifier '=' _expression ':' _expression ( ':' _expression )?

_forall_control_expression ::=
	 [fF][oO][rR][aA][lL][lL] '(' triplet_spec ( ',' triplet_spec )* ( ',' ( logical_expression | relational_expression ) )? ')'

_inline_forall_statement ::=
	 _forall_control_expression _statements

_block_forall_statement ::=
	 block_label_start_expression? _forall_control_expression _end_of_statement _statement* statement_label? end_forall_statement

end_forall_statement ::=
	 ( [eE][nN][dD] [fF][oO][rR][aA][lL][lL] | [eE][nN][dD][fF][oO][rR][aA][lL][lL] ) _block_label?

select_case_statement ::=
	 block_label_start_expression? ( [sS][eE][lL][eE][cC][tT] [cC][aA][sS][eE] | [sS][eE][lL][eE][cC][tT][cC][aA][sS][eE] ) selector _end_of_statement case_statement+ statement_label? end_select_statement

select_type_statement ::=
	 block_label_start_expression? ( [sS][eE][lL][eE][cC][tT] [tT][yY][pP][eE] | [sS][eE][lL][eE][cC][tT][tT][yY][pP][eE] ) selector _end_of_statement type_statement+ statement_label? end_select_statement

select_rank_statement ::=
	 block_label_start_expression? ( [sS][eE][lL][eE][cC][tT] [rR][aA][nN][kK] | [sS][eE][lL][eE][cC][tT][rR][aA][nN][kK] ) selector _end_of_statement rank_statement+ statement_label? end_select_statement

end_select_statement ::=
	 ( [eE][nN][dD] [sS][eE][lL][eE][cC][tT] | [eE][nN][dD][sS][eE][lL][eE][cC][tT] ) _block_label?

selector ::=
	 '(' ( _expression | pointer_association_statement ) ')'

case_statement ::=
	 [cC][aA][sS][eE] ( '(' case_value_range_list ')' | [dD][eE][fF][aA][uU][lL][tT] ) _block_label? _end_of_statement _statement*

type_statement ::=
	 ( ( ( [tT][yY][pP][eE] [iI][sS] | [tT][yY][pP][eE][iI][sS] ) | ( [cC][lL][aA][sS][sS] [iI][sS] | [cC][lL][aA][sS][sS][iI][sS] ) ) ( '(' ( _intrinsic_type | identifier ) ')' ) | _class_default ) _block_label? _end_of_statement _statement*

_class_default ::=
	 [cC][lL][aA][sS][sS] [dD][eE][fF][aA][uU][lL][tT]
	| [cC][lL][aA][sS][sS][dD][eE][fF][aA][uU][lL][tT]

case_value_range_list ::=
	 ( _expression | extent_specifier ) ( ',' ( _expression | extent_specifier ) )*

rank_statement ::=
	 [rR][aA][nN][kK] ( '(' case_value_range_list ')' | [dD][eE][fF][aA][uU][lL][tT] ) _block_label? _end_of_statement _statement*

block_construct ::=
	 block_label_start_expression? [bB][lL][oO][cC][kK] _end_of_statement _specification_part* _statement* end_block_construct_statement

end_block_construct_statement ::=
	 ( [eE][nN][dD] [bB][lL][oO][cC][kK] | [eE][nN][dD][bB][lL][oO][cC][kK] ) _block_label?

associate_statement ::=
	 block_label_start_expression? [aA][sS][sS][oO][cC][iI][aA][tT][eE] '(' association ( ',' association )* ')' _end_of_statement _statement* end_associate_statement

association ::=
	 identifier '=>' _expression

end_associate_statement ::=
	 ( [eE][nN][dD] [aA][sS][sS][oO][cC][iI][aA][tT][eE] | [eE][nN][dD][aA][sS][sS][oO][cC][iI][aA][tT][eE] ) _block_label?

format_statement ::=
	 [fF][oO][rR][mM][aA][tT] '(' _transfer_items ')'

_transfer_item ::=
	 string_literal
	| edit_descriptor
	| hollerith_constant
	| '(' _transfer_items ')'

_transfer_items ::=
	 _transfer_item ( ','? _transfer_item )*

edit_descriptor ::=
	 [a-gi-zA-GI-Z0-9/:.*$]+

hollerith_constant ::=
	 [0-9]+'H'[^/,)]+

_io_arguments ::=
	 '(' ( unit_identifier | unit_identifier ',' format_identifier | unit_identifier ',' format_identifier ',' keyword_argument ( ',' keyword_argument )* | unit_identifier ',' keyword_argument ( ',' keyword_argument )* | keyword_argument ( ',' keyword_argument )* ) ')'

read_statement ::=
	 _simple_read_statement | _parameterized_read_statement

_simple_read_statement ::=
	 [rR][eE][aA][dD] format_identifier ( ',' input_item_list )?

_parameterized_read_statement ::=
	 [rR][eE][aA][dD] _io_arguments input_item_list?

print_statement ::=
	 [pP][rR][iI][nN][tT] format_identifier ( ',' output_item_list )?

open_statement ::=
	 [oO][pP][eE][nN] _io_arguments output_item_list?

close_statement ::=
	 [cC][lL][oO][sS][eE] '(' ( unit_identifier | unit_identifier ',' keyword_argument ( ',' keyword_argument )* | keyword_argument ( ',' keyword_argument )* ) ')'

write_statement ::=
	 [wW][rR][iI][tT][eE] _io_arguments ','? output_item_list?

inquire_statement ::=
	 [iI][nN][qQ][uU][iI][rR][eE] _io_arguments output_item_list?

enum ::=
	 enum_statement enumerator_statement* end_enum_statement _end_of_statement

enum_statement ::=
	 [eE][nN][uU][mM] ',' language_binding

enumerator_statement ::=
	 [eE][nN][uU][mM][eE][rR][aA][tT][oO][rR] '::'? ( identifier | identifier '=' ( number_literal | unary_expression ) ) ( ',' ( identifier | identifier '=' ( number_literal | unary_expression ) ) )*

end_enum_statement ::=
	 ( [eE][nN][dD] [eE][nN][uU][mM] | [eE][nN][dD][eE][nN][uU][mM] )

unit_identifier ::=
	 number_literal | _io_expressions

format_identifier ::=
	 statement_label_reference
	| _io_expressions

_file_position_spec ::=
	 unit_identifier
	| '(' unit_identifier ',' keyword_argument ( ',' keyword_argument )* ')'
	| '(' keyword_argument ( ',' keyword_argument )* ')'

file_position_statement ::=
	 [bB][aA][cC][kK][sS][pP][aA][cC][eE] _file_position_spec
	| [eE][nN][dD][fF][iI][lL][eE] _file_position_spec
	| [rR][eE][wW][iI][nN][dD] _file_position_spec
	| [pP][aA][uU][sS][eE] string_literal?

_io_expressions ::=
	 '*' | string_literal | identifier | derived_type_member_expression | concatenation_expression | math_expression | parenthesized_expression | call_expression

input_item_list ::=
	 _expression ( ',' _expression )*

output_item_list ::=
	 _expression ( ',' _expression )*

_expression ::=
	 number_literal
	| complex_literal
	| string_literal
	| boolean_literal
	| array_literal
	| null_literal
	| identifier
	| derived_type_member_expression
	| logical_expression
	| relational_expression
	| concatenation_expression
	| math_expression
	| unary_expression
	| parenthesized_expression
	| call_expression
	| implied_do_loop_expression

parenthesized_expression ::=
	 '(' _expression ')'

derived_type_member_expression ::=
	 _expression '%' identifier

logical_expression ::=
	 _expression '.'[oO][rR]'.' _expression
	| _expression '.'[aA][nN][dD]'.' _expression
	| _expression '.'[eE][qQ][vV]'.' _expression
	| _expression '.'[nN][eE][qQ][vV]'.' _expression
	| '.'[nN][oO][tT]'.' _expression

relational_expression ::=
	 _expression '<' _expression
	| _expression '.'[lL][tT]'.' _expression
	| _expression '>' _expression
	| _expression '.'[gG][tT]'.' _expression
	| _expression '<=' _expression
	| _expression '.'[lL][eE]'.' _expression
	| _expression '>=' _expression
	| _expression '.'[gG][eE]'.' _expression
	| _expression '==' _expression
	| _expression '.'[eE][qQ]'.' _expression
	| _expression '/=' _expression
	| _expression '.'[nN][eE]'.' _expression

concatenation_expression ::=
	 _expression '//' _expression

math_expression ::=
	 _expression '+' _expression
	| _expression '-' _expression
	| _expression '*' _expression
	| _expression '/' _expression
	| _expression '**' _expression
	| _expression user_defined_operator _expression

unary_expression ::=
	 ( '-' | '+' | user_defined_operator ) _expression

user_defined_operator ::=
	 '.' [a-zA-Z]+ '.'

call_expression ::=
	 _expression argument_list+

implied_do_loop_expression ::=
	 '(' _expression ( ',' _expression )* ',' loop_control_expression ')'

argument_list ::=
	 '(' ( ( keyword_argument | extent_specifier | assumed_size | assumed_rank | _expression ) ( ',' ( keyword_argument | extent_specifier | assumed_size | assumed_rank | _expression ) )* )? ')'

keyword_argument ::=
	 identifier '=' ( _expression | assumed_size | assumed_shape )

extent_specifier ::=
	 _expression? ':' ( _expression | assumed_size )? ( ':' _expression )?

assumed_size ::=
	 '*'

assumed_shape ::=
	 ':'

assumed_rank ::=
	 '..'

block_label_start_expression ::=
	 identifier ':'

_block_label ::=
	 identifier

loop_control_expression ::=
	 identifier '=' _expression ',' _expression ( ',' _expression )?

array_literal ::=
	 _array_constructor_legacy
	| _array_constructor_f2003

_array_constructor_legacy ::=
	 '(/' _ac_value_list '/)'

_array_constructor_f2003 ::=
	 '[' _ac_value_list ']'

_type_spec ::=
	 ( _intrinsic_type | derived_type ) '::'

_ac_value_list ::=
	 _type_spec
	| _type_spec? _expression ( ',' _expression )*

complex_literal ::=
	 '(' ( number_literal | identifier | unary_expression ) ',' ( number_literal | identifier | unary_expression ) ')'

number_literal ::=
	 _integer_literal
	| _float_literal
	| _boz_literal

boolean_literal ::=
	 ( ( '.'[tT][rR][uU][eE]'.' | '.'[fF][aA][lL][sS][eE]'.' ) ( '_' [a-zA-Z_]+ )? )

null_literal ::=
	 [nN][uU][lL][lL] '(' ')'

preproc_file_line ::=
	 '#' [0-9]+ '"'[^"#x0A]*'"' [0-9]+? _newline

identifier ::=
	 [a-zA-Z_][a-zA-Z_]*
	| [bB][lL][oO][cC][kK]
	| [bB][yY][tT][eE]
	| [cC][yY][cC][lL][eE]
	| [dD][aA][tT][aA]
	| [dD][oO][uU][bB][lL][eE]
	| [eE][lL][sS][eE][iI][fF]
	| [eE][nN][dD]
	| [eE][nN][dD][iI][fF]
	| [eE][rR][rR][oO][rR]
	| [eE][xX][iI][tT]
	| [fF][oO][rR][mM][aA][tT]
	| [iI][fF]
	| [iI][nN][qQ][uU][iI][rR][eE]
	| [nN][uU][lL][lL]
	| [rR][eE][aA][dD]
	| [rR][eE][aA][lL]
	| [sS][eE][lL][eE][cC][tT]
	| [sS][tT][oO][pP]
	| [tT][aA][rR][gG][eE][tT]
	| [vV][aA][lL][uU][eE]
	| [wW][rR][iI][tT][eE]

comment ::=
	 ( '!' '.'* )

_line_continuation ::=
	 '&'

_semicolon ::=
	 ';'

_newline ::=
	 '\n'