translation-unit:
    ||-->--------------------------v--||
        |                          |
        `-- external-declaration --'

external-declaration:
    ||--v-- function-definition -->--||
        |                         |
        `------ declaration ------'

function-definition:
                                                ,---------->-----------.
                                                |                      |
    ||-- declaration-specifiers -- declarator --^-- declaration-list -->-- compound-statement --||

declaration:
                                     ,------------>-------------.
                                     |                          |
    ||--v-- declaration-specifiers --^-- init-declarator-list -->-- ";" -->--||
        |                                                                 |
        >------------------- static-assert-declaration -------------------^
        |                                                                 |
        `------------------------------ ";" ------------------------------'

declaration-specifiers:
    ||-->-- declaration-specifier --v--||
        |                           |
        `-------------<-------------'

declaration-specifier:
    ||--v-- storage-class-specifier -->--||
        |                             |
        >------ type-specifier -------^
        |                             |
        >------ type-qualifier -------^
        |                             |
        >---- function-specifier -----^
        |                             |
        `---- alignment-specifier ----'

declarator:
        ,------>------.
        |             |
    ||--^-- pointer -->-- direct-declarator --||

declaration-list:
    ||-->-- declaration --v--||
        |                 |
        `--------<--------'

compound-statement:
    ||-- "{" -->------------------------------v-- "}" --||
               |                              |
               `-- declaration-or-statement --'

declaration-or-statement:
    ||--v-- declaration -->--||
        |                 |
        `--- statement ---'

init-declarator-list:
    ||-->-- init-declarator --v--||
        |                     |
        `-------- "," --------'

init-declarator:
                      ,----------->------------.
                      |                        |
    ||-- declarator --^-- "=" -- initializer -->--||

static-assert-declaration:
    ||-- "_Static_assert" -- "(" -- constant-expression -- "," -- string-literal -- ")" -- ";" --||

storage-class-specifier:
    ||--v----- "typedef" ----->--||
        |                     |
        >----- "extern" ------^
        |                     |
        >----- "static" ------^
        |                     |
        >-- "_Thread_local" --^
        |                     |
        >------ "auto" -------^
        |                     |
        `---- "register" -----'

type-specifier:
    ||--v----------- "void" ------------>--||
        |                               |
        >----------- "char" ------------^
        |                               |
        >----------- "short" -----------^
        |                               |
        >------------ "int" ------------^
        |                               |
        >----------- "long" ------------^
        |                               |
        >----------- "float" -----------^
        |                               |
        >---------- "double" -----------^
        |                               |
        >---------- "signed" -----------^
        |                               |
        >--------- "unsigned" ----------^
        |                               |
        >----------- "_Bool" -----------^
        |                               |
        >--------- "_Complex" ----------^
        |                               |
        >-------- "_Imaginary" ---------^
        |                               |
        >---- atomic-type-specifier ----^
        |                               |
        >-- struct-or-union-specifier --^
        |                               |
        >------- enum-specifier --------^
        |                               |
        `-------- typedef-name ---------'

typedef-name:
    ||-- identifier --||

type-qualifier:
    ||--v--- "const" ---->--||
        |                |
        >-- "restrict" --^
        |                |
        >-- "volatile" --^
        |                |
        `-- "_Atomic" ---'

function-specifier:
    ||--v--- "inline" ---->--||
        |                 |
        `-- "_Noreturn" --'

alignment-specifier:
    ||--v------- "_Alignas" -- "(" -- type-name -- ")" ------->--||
        |                                                     |
        `-- "_Alignas" -- "(" -- constant-expression -- ")" --'

pointer:
               ,------------>------------.  ,------>------.
               |                         |  |             |
    ||-- "*" --^-- type-qualifier-list -->--^-- pointer -->--||

direct-declarator:
    ||--v--------------------------------------------- identifier ---------------------------------------------->--||
        |                                                                                                       |
        >-------------------------------------- "(" -- declarator -- ")" ---------------------------------------^
        |                                                                                                       |
        |                                                        ,---->----.                                    |
        |                                                        |         |                                    |
        >---------------------------- direct-declarator -- "[" --^-- "*" -->-- "]" -----------------------------^
        |                                                                                                       |
        |                                          ,------------>------------.                                  |
        |                                          |                         |                                  |
        >-- direct-declarator -- "[" -- "static" --^-- type-qualifier-list -->-- assignment-expression -- "]" --^
        |                                                                                                       |
        |                                                                    ,---->----.                        |
        |                                                                    |         |                        |
        >----------------- direct-declarator -- "[" -- type-qualifier-list --^-- "*" -->-- "]" -----------------^
        |                                                                                                       |
        |                                                     ,------>-------.                                  |
        |                                                     |              |                                  |
        >-- direct-declarator -- "[" -- type-qualifier-list --^-- "static" -->-- assignment-expression -- "]" --^
        |                                                                                                       |
        >---------------------- direct-declarator -- "[" -- assignment-expression -- "]" -----------------------^
        |                                                                                                       |
        >----------------------- direct-declarator -- "(" -- parameter-type-list -- ")" ------------------------^
        |                                                                                                       |
        >------------------------- direct-declarator -- "(" -- identifier-list -- ")" --------------------------^
        |                                                                                                       |
        `----------------------------------- direct-declarator -- "(" -- ")" -----------------------------------'

identifier-list:
    ||-->-- identifier --v--||
        |                |
        `----- "," ------'

initializer-list:
    ||-->-- designative-initializer --v--||
        |                             |
        `------------ "," ------------'

designative-initializer:
        ,-------->--------.
        |                 |
    ||--^-- designation -->-- initializer --||

initializer:
                                      ,---->----.
                                      |         |
    ||--v-- "{" -- initializer-list --^-- "," -->-- "}" -->--||
        |                                                 |
        `------------- assignment-expression -------------'

constant-expression:
    ||-- conditional-expression --||

atomic-type-specifier:
    ||-- "_Atomic" -- "(" -- type-name -- ")" --||

struct-or-union-specifier:
    ||--v------------ struct-or-union -- "{" -- struct-declaration-list -- "}" ------------>--||
        |                                                                                  |
        |                                   ,--------------------->---------------------.  |
        |                                   |                                           |  |
        `-- struct-or-union -- identifier --^-- "{" -- struct-declaration-list -- "}" -->--'

struct-or-union:
    ||--v-- "struct" -->--||
        |              |
        `-- "union" ---'

struct-declaration-list:
    ||-->-- struct-declaration --v--||
        |                        |
        `-----------<------------'

struct-declaration:
    ||--v--------------- specifier-qualifier-list -- ";" --------------->--||
        |                                                               |
        >-- specifier-qualifier-list -- struct-declarator-list -- ";" --^
        |                                                               |
        `------------------ static-assert-declaration ------------------'

enum-specifier:
                                                         ,---->----.
                                                         |         |
    ||--v------------ "enum" -- "{" -- enumerator-list --^-- "," -->-- "}" ------------>--||
        |                                                                              |
        |                          ,----------------------->------------------------.  |
        |                          |                                                |  |
        |                          |                            ,---->----.         |  |
        |                          |                            |         |         |  |
        `-- "enum" -- identifier --^-- "{" -- enumerator-list --^-- "," -->-- "}" -->--'

enumerator-list:
    ||-->-- enumerator --v--||
        |                |
        `----- "," ------'

enumerator:
                                ,--------------->----------------.
                                |                                |
    ||-- enumeration-constant --^-- "=" -- constant-expression -->--||

enumeration-constant:
    ||-- identifier --||

type-name:
                                    ,------------>------------.
                                    |                         |
    ||-- specifier-qualifier-list --^-- abstract-declarator -->--||

specifier-qualifier-list:
    ||-->-- specifier-qualifier --v--||
        |                         |
        `------------<------------'

specifier-qualifier:
    ||--v-- type-specifier -->--||
        |                    |
        `-- type-qualifier --'

abstract-declarator:
                      ,--------------->----------------.
                      |                                |
    ||--v-- pointer --^-- direct-abstract-declarator -->-->--||
        |                                                 |
        `---------- direct-abstract-declarator -----------'

direct-abstract-declarator:
    ||--v----------------------------------------- "(" -- abstract-declarator -- ")" ------------------------------------------>--||
        |                                                                                                                      |
        >----------------------------------------- "(" -- parameter-type-list -- ")" ------------------------------------------^
        |                                                                                                                      |
        >----------------------------------------------------- "(" -- ")" -----------------------------------------------------^
        |                                                                                                                      |
        |                                                     ,---->----.                                                      |
        |                                                     |         |                                                      |
        >---------------------------------------------- "[" --^-- "*" -->-- "]" -----------------------------------------------^
        |                                                                                                                      |
        |                                       ,------------>------------.                                                    |
        |                                       |                         |                                                    |
        >-------------------- "[" -- "static" --^-- type-qualifier-list -->-- assignment-expression -- "]" --------------------^
        |                                                                                                                      |
        |                                               ,---------------------->----------------------.                        |
        |                                               |                                             |                        |
        |                                               |  ,------>-------.                           |                        |
        |                                               |  |              |                           |                        |
        >----------------- "[" -- type-qualifier-list --^--^-- "static" -->-- assignment-expression -->-- "]" -----------------^
        |                                                                                                                      |
        >---------------------------------------- "[" -- assignment-expression -- "]" -----------------------------------------^
        |                                                                                                                      |
        |                                                                    ,---->----.                                       |
        |                                                                    |         |                                       |
        >------------------------------- direct-abstract-declarator -- "[" --^-- "*" -->-- "]" --------------------------------^
        |                                                                                                                      |
        |                                                      ,------------>------------.                                     |
        |                                                      |                         |                                     |
        >----- direct-abstract-declarator -- "[" -- "static" --^-- type-qualifier-list -->-- assignment-expression -- "]" -----^
        |                                                                                                                      |
        |                                                              ,---------------------->----------------------.         |
        |                                                              |                                             |         |
        |                                                              |  ,------>-------.                           |         |
        |                                                              |  |              |                           |         |
        >-- direct-abstract-declarator -- "[" -- type-qualifier-list --^--^-- "static" -->-- assignment-expression -->-- "]" --^
        |                                                                                                                      |
        >------------------------- direct-abstract-declarator -- "[" -- assignment-expression -- "]" --------------------------^
        |                                                                                                                      |
        >-------------------------- direct-abstract-declarator -- "(" -- parameter-type-list -- ")" ---------------------------^
        |                                                                                                                      |
        `-------------------------------------- direct-abstract-declarator -- "(" -- ")" --------------------------------------'

struct-declarator-list:
    ||-->-- struct-declarator --v--||
        |                       |
        `--------- "," ---------'

type-qualifier-list:
    ||-->-- type-qualifier --v--||
        |                    |
        `---------<----------'

parameter-type-list:
                          ,-------->---------.
                          |                  |
    ||-- parameter-list --^-- "," -- "..." -->--||

struct-declarator:
    ||--v------------ ":" -- constant-expression ------------>--||
        |                                                    |
        |                ,--------------->----------------.  |
        |                |                                |  |
        `-- declarator --^-- ":" -- constant-expression -->--'

assignment-operator:
    ||--v--- "=" --->--||
        |           |
        >-- "*=" ---^
        |           |
        >-- "/=" ---^
        |           |
        >-- "%=" ---^
        |           |
        >-- "+=" ---^
        |           |
        >-- "-=" ---^
        |           |
        >-- "<<=" --^
        |           |
        >-- ">>=" --^
        |           |
        >-- "&=" ---^
        |           |
        >-- "^=" ---^
        |           |
        `-- "|=" ---'

parameter-list:
    ||-->-- parameter-declaration --v--||
        |                           |
        `----------- "," -----------'

parameter-declaration:
                                  ,------------>------------.
                                  |                         |
    ||-- declaration-specifiers --+------ declarator ------->--||
                                  |                         |
                                  `-- abstract-declarator --'

expression:
    ||-->-- assignment-expression --v--||
        |                           |
        `----------- "," -----------'

assignment-expression:
    ||--v----------------------- conditional-expression ----------------------->--||
        |                                                                      |
        `-- unary-expression -- assignment-operator -- assignment-expression --'

conditional-expression:
                                 ,--------------------------->----------------------------.
                                 |                                                        |
    ||-- logical-or-expression --^-- "?" -- expression -- ":" -- conditional-expression -->--||

logical-or-expression:
    ||-->-- logical-and-expression --v--||
        |                            |
        `----------- "||" -----------'

logical-and-expression:
    ||-->-- inclusive-or-expression --v--||
        |                             |
        `----------- "&&" ------------'

inclusive-or-expression:
    ||-->-- exclusive-or-expression --v--||
        |                             |
        `------------ "|" ------------'

exclusive-or-expression:
    ||-->-- and-expression --v--||
        |                    |
        `------- "^" --------'

and-expression:
    ||-->-- equality-expression --v--||
        |                         |
        `---------- "&" ----------'

equality-expression:
    ||-->-- relational-expression --v--||
        |                           |
        `-------<-- "==" --v--------'
                |          |
                `-- "!=" --'

relational-expression:
    ||-->-- shift-expression --v--||
        |                      |
        `-----<-- "<" ---v-----'
              |          |
              ^-- ">" ---<
              |          |
              ^-- "<=" --<
              |          |
              `-- ">=" --'

shift-expression:
    ||-->-- additive-expression --v--||
        |                         |
        `------<-- "<<" --v-------'
               |          |
               `-- ">>" --'

additive-expression:
    ||-->-- multiplicative-expression --v--||
        |                               |
        `----------<-- "+" --v----------'
                   |         |
                   `-- "-" --'

multiplicative-expression:
    ||-->-- cast-expression --v--||
        |                     |
        `-----<-- "%" --v-----'
              |         |
              ^-- "*" --<
              |         |
              `-- "/" --'

cast-expression:
    ||--v--------------- unary-expression --------------->--||
        |                                                |
        `-- "(" -- type-name -- ")" -- cast-expression --'

unary-expression:
    ||--v----------- postfix-expression ------------>--||
        |                                           |
        >-----v-- "++" -->-- unary-expression ------^
        |     |          |                          |
        |     `-- "--" --'                          |
        |                                           |
        >---- unary-operator -- cast-expression ----^
        |                                           |
        >------ "sizeof" -- unary-expression -------^
        |                                           |
        >--- "sizeof" -- "(" -- type-name -- ")" ---^
        |                                           |
        `-- "_Alignof" -- "(" -- type-name -- ")" --'

postfix-expression:
    ||--v---------------------------- primary-expression ---------------------------->--||
        |                                                                            |
        >-------------- postfix-expression -- "[" -- expression -- "]" --------------^
        |                                                                            |
        |                                 ,-------------->---------------.           |
        |                                 |                              |           |
        >---- postfix-expression -- "(" --^-- argument-expression-list -->-- ")" ----^
        |                                                                            |
        >-------------- postfix-expression --v-- "." --->-- identifier --------------^
        |                                    |          |                            |
        |                                    `-- "->" --'                            |
        |                                                                            |
        >--------------------- postfix-expression --v-- "++" -->---------------------^
        |                                           |          |                     |
        |                                           `-- "--" --'                     |
        |                                                                            |
        |                                                        ,---->----.         |
        |                                                        |         |         |
        `-- "(" -- type-name -- ")" -- "{" -- initializer-list --^-- "," -->-- "}" --'

unary-operator:
    ||--v-- "!" -->--||
        |         |
        >-- "&" --^
        |         |
        >-- "*" --^
        |         |
        >-- "+" --^
        |         |
        >-- "-" --^
        |         |
        `-- "~" --'

primary-expression:
    ||--v--------- identifier --------->--||
        |                              |
        >---------- constant ----------^
        |                              |
        >----------- string -----------^
        |                              |
        >-- "(" -- expression -- ")" --^
        |                              |
        `----- generic-selection ------'

argument-expression-list:
    ||-->-- assignment-expression --v--||
        |                           |
        `----------- "," -----------'

constant:
    ||--v---- integer-constant ---->--||
        |                          |
        >--- character-constant ---^
        |                          |
        >--- floating-constant ----^
        |                          |
        `-- enumeration-constant --'

string:
    ||--v-- string-literal -->--||
        |                    |
        `---- "__func__" ----'

generic-selection:
    ||-- "_Generic" -- "(" -- assignment-expression -- "," -- generic-assoc-list -- ")" --||

generic-assoc-list:
    ||-->-- generic-association --v--||
        |                         |
        `---------- "," ----------'

generic-association:
    ||--v-- type-name -- ":" -- assignment-expression -->--||
        |                                               |
        `-- "default" -- ":" -- assignment-expression --'

designation:
    ||-- designator-list -- "=" --||

designator-list:
    ||-->-- designator --v--||
        |                |
        `-------<--------'

designator:
    ||--v-- "[" -- constant-expression -- "]" -->--||
        |                                       |
        `---------- "." -- identifier ----------'

statement:
    ||--v--- labeled-statement ---->--||
        |                          |
        >--- compound-statement ---^
        |                          |
        >-- expression-statement --^
        |                          |
        >-- selection-statement ---^
        |                          |
        >-- iteration-statement ---^
        |                          |
        `----- jump-statement -----'

labeled-statement:
    ||--v----------- identifier -- ":" -- statement ------------>--||
        |                                                       |
        >-- "case" -- constant-expression -- ":" -- statement --^
        |                                                       |
        `------------ "default" -- ":" -- statement ------------'

expression-statement:
        ,------->--------.
        |                |
    ||--^-- expression -->-- ";" --||

selection-statement:
    ||--v-- "if" -- "(" -- expression -- ")" -- statement -- "else" -- statement -->--||
        |                                                                          |
        >------------- "if" -- "(" -- expression -- ")" -- statement --------------^
        |                                                                          |
        `----------- "switch" -- "(" -- expression -- ")" -- statement ------------'

iteration-statement:
    ||--v------------------------------- "while" -- "(" -- expression -- ")" -- statement ------------------------------->--||
        |                                                                                                                |
        >----------------------- "do" -- statement -- "while" -- "(" -- expression -- ")" -- ";" ------------------------^
        |                                                                                                                |
        |                  ,------->--------.         ,------->--------.         ,------->--------.                      |
        |                  |                |         |                |         |                |                      |
        >-- "for" -- "(" --^-- expression -->-- ";" --^-- expression -->-- ";" --^-- expression -->-- ")" -- statement --^
        |                                                                                                                |
        |                                       ,------->--------.         ,------->--------.                            |
        |                                       |                |         |                |                            |
        `-------- "for" -- "(" -- declaration --^-- expression -->-- ";" --^-- expression -->-- ")" -- statement --------'

jump-statement:
    ||--v------ "goto" -- identifier -- ";" ------>--||
        |                                         |
        >----------- "continue" -- ";" -----------^
        |                                         |
        >------------ "break" -- ";" -------------^
        |                                         |
        |              ,------->--------.         |
        |              |                |         |
        `-- "return" --^-- expression -->-- ";" --'