Grammar

grammar.y

  1. Root <- skip container_doc_comment? ContainerMembers eof
  3. # *** Top level ***
  4. ContainerMembers <- ContainerDeclarations (ContainerField COMMA)* (ContainerField / ContainerDeclarations)
  6. ContainerDeclarations
  7.     <- TestDecl ContainerDeclarations
  8.      / TopLevelComptime ContainerDeclarations
  9.      / doc_comment? KEYWORD_pub? TopLevelDecl ContainerDeclarations
  10.      /
  12. TestDecl <- doc_comment? KEYWORD_test STRINGLITERALSINGLE? Block
  14. TopLevelComptime <- doc_comment? KEYWORD_comptime BlockExpr
  16. TopLevelDecl
  17.     <- (KEYWORD_export / KEYWORD_extern STRINGLITERALSINGLE? / (KEYWORD_inline / KEYWORD_noinline))? FnProto (SEMICOLON / Block)
  18.      / (KEYWORD_export / KEYWORD_extern STRINGLITERALSINGLE?)? KEYWORD_threadlocal? VarDecl
  19.      / KEYWORD_usingnamespace Expr SEMICOLON
  21. FnProto <- KEYWORD_fn IDENTIFIER? LPAREN ParamDeclList RPAREN ByteAlign? LinkSection? CallConv? EXCLAMATIONMARK? TypeExpr
  23. VarDecl <- (KEYWORD_const / KEYWORD_var) IDENTIFIER (COLON TypeExpr)? ByteAlign? LinkSection? (EQUAL Expr)? SEMICOLON
  25. ContainerField <- doc_comment? KEYWORD_comptime? IDENTIFIER (COLON (KEYWORD_anytype / TypeExpr) ByteAlign?)? (EQUAL Expr)?
  27. # *** Block Level ***
  28. Statement
  29.     <- KEYWORD_comptime? VarDecl
  30.      / KEYWORD_comptime BlockExprStatement
  31.      / KEYWORD_nosuspend BlockExprStatement
  32.      / KEYWORD_suspend BlockExprStatement
  33.      / KEYWORD_defer BlockExprStatement
  34.      / KEYWORD_errdefer Payload? BlockExprStatement
  35.      / IfStatement
  36.      / LabeledStatement
  37.      / SwitchExpr
  38.      / AssignExpr SEMICOLON
  40. IfStatement
  41.     <- IfPrefix BlockExpr ( KEYWORD_else Payload? Statement )?
  42.      / IfPrefix AssignExpr ( SEMICOLON / KEYWORD_else Payload? Statement )
  44. LabeledStatement <- BlockLabel? (Block / LoopStatement)
  46. LoopStatement <- KEYWORD_inline? (ForStatement / WhileStatement)
  48. ForStatement
  49.     <- ForPrefix BlockExpr ( KEYWORD_else Statement )?
  50.      / ForPrefix AssignExpr ( SEMICOLON / KEYWORD_else Statement )
  52. WhileStatement
  53.     <- WhilePrefix BlockExpr ( KEYWORD_else Payload? Statement )?
  54.      / WhilePrefix AssignExpr ( SEMICOLON / KEYWORD_else Payload? Statement )
  56. BlockExprStatement
  57.     <- BlockExpr
  58.      / AssignExpr SEMICOLON
  60. BlockExpr <- BlockLabel? Block
  62. # *** Expression Level ***
  63. AssignExpr <- Expr (AssignOp Expr)?
  65. Expr <- BoolOrExpr
  67. BoolOrExpr <- BoolAndExpr (KEYWORD_or BoolAndExpr)*
  69. BoolAndExpr <- CompareExpr (KEYWORD_and CompareExpr)*
  71. CompareExpr <- BitwiseExpr (CompareOp BitwiseExpr)?
  73. BitwiseExpr <- BitShiftExpr (BitwiseOp BitShiftExpr)*
  75. BitShiftExpr <- AdditionExpr (BitShiftOp AdditionExpr)*
  77. AdditionExpr <- MultiplyExpr (AdditionOp MultiplyExpr)*
  79. MultiplyExpr <- PrefixExpr (MultiplyOp PrefixExpr)*
  81. PrefixExpr <- PrefixOp* PrimaryExpr
  83. PrimaryExpr
  84.     <- AsmExpr
  85.      / IfExpr
  86.      / KEYWORD_break BreakLabel? Expr?
  87.      / KEYWORD_comptime Expr
  88.      / KEYWORD_nosuspend Expr
  89.      / KEYWORD_continue BreakLabel?
  90.      / KEYWORD_resume Expr
  91.      / KEYWORD_return Expr?
  92.      / BlockLabel? LoopExpr
  93.      / Block
  94.      / CurlySuffixExpr
  96. IfExpr <- IfPrefix Expr (KEYWORD_else Payload? Expr)?
  98. Block <- LBRACE Statement* RBRACE
  100. LoopExpr <- KEYWORD_inline? (ForExpr / WhileExpr)
  102. ForExpr <- ForPrefix Expr (KEYWORD_else Expr)?
  104. WhileExpr <- WhilePrefix Expr (KEYWORD_else Payload? Expr)?
  106. CurlySuffixExpr <- TypeExpr InitList?
  108. InitList
  109.     <- LBRACE FieldInit (COMMA FieldInit)* COMMA? RBRACE
  110.      / LBRACE Expr (COMMA Expr)* COMMA? RBRACE
  111.      / LBRACE RBRACE
  113. TypeExpr <- PrefixTypeOp* ErrorUnionExpr
  115. ErrorUnionExpr <- SuffixExpr (EXCLAMATIONMARK TypeExpr)?
  117. SuffixExpr
  118.     <- KEYWORD_async PrimaryTypeExpr SuffixOp* FnCallArguments
  119.      / PrimaryTypeExpr (SuffixOp / FnCallArguments)*
  121. PrimaryTypeExpr
  122.     <- BUILTINIDENTIFIER FnCallArguments
  123.      / CHAR_LITERAL
  124.      / ContainerDecl
  125.      / DOT IDENTIFIER
  126.      / DOT InitList
  127.      / ErrorSetDecl
  128.      / FLOAT
  129.      / FnProto
  130.      / GroupedExpr
  131.      / LabeledTypeExpr
  132.      / IDENTIFIER
  133.      / IfTypeExpr
  134.      / INTEGER
  135.      / KEYWORD_comptime TypeExpr
  136.      / KEYWORD_error DOT IDENTIFIER
  137.      / KEYWORD_anyframe
  138.      / KEYWORD_unreachable
  139.      / STRINGLITERAL
  140.      / SwitchExpr
  142. ContainerDecl <- (KEYWORD_extern / KEYWORD_packed)? ContainerDeclAuto
  144. ErrorSetDecl <- KEYWORD_error LBRACE IdentifierList RBRACE
  146. GroupedExpr <- LPAREN Expr RPAREN
  148. IfTypeExpr <- IfPrefix TypeExpr (KEYWORD_else Payload? TypeExpr)?
  150. LabeledTypeExpr
  151.     <- BlockLabel Block
  152.      / BlockLabel? LoopTypeExpr
  154. LoopTypeExpr <- KEYWORD_inline? (ForTypeExpr / WhileTypeExpr)
  156. ForTypeExpr <- ForPrefix TypeExpr (KEYWORD_else TypeExpr)?
  158. WhileTypeExpr <- WhilePrefix TypeExpr (KEYWORD_else Payload? TypeExpr)?
  160. SwitchExpr <- KEYWORD_switch LPAREN Expr RPAREN LBRACE SwitchProngList RBRACE
  162. # *** Assembly ***
  163. AsmExpr <- KEYWORD_asm KEYWORD_volatile? LPAREN Expr AsmOutput? RPAREN
  165. AsmOutput <- COLON AsmOutputList AsmInput?
  167. AsmOutputItem <- LBRACKET IDENTIFIER RBRACKET STRINGLITERAL LPAREN (MINUSRARROW TypeExpr / IDENTIFIER) RPAREN
  169. AsmInput <- COLON AsmInputList AsmClobbers?
  171. AsmInputItem <- LBRACKET IDENTIFIER RBRACKET STRINGLITERAL LPAREN Expr RPAREN
  173. AsmClobbers <- COLON StringList
  175. # *** Helper grammar ***
  176. BreakLabel <- COLON IDENTIFIER
  178. BlockLabel <- IDENTIFIER COLON
  180. FieldInit <- DOT IDENTIFIER EQUAL Expr
  182. WhileContinueExpr <- COLON LPAREN AssignExpr RPAREN
  184. LinkSection <- KEYWORD_linksection LPAREN Expr RPAREN
  186. # Fn specific
  187. CallConv <- KEYWORD_callconv LPAREN Expr RPAREN
  189. ParamDecl
  190.     <- doc_comment? (KEYWORD_noalias / KEYWORD_comptime)? (IDENTIFIER COLON)? ParamType
  191.      / DOT3
  193. ParamType
  194.     <- KEYWORD_anytype
  195.      / TypeExpr
  197. # Control flow prefixes
  198. IfPrefix <- KEYWORD_if LPAREN Expr RPAREN PtrPayload?
  200. WhilePrefix <- KEYWORD_while LPAREN Expr RPAREN PtrPayload? WhileContinueExpr?
  202. ForPrefix <- KEYWORD_for LPAREN Expr RPAREN PtrIndexPayload
  204. # Payloads
  205. Payload <- PIPE IDENTIFIER PIPE
  207. PtrPayload <- PIPE ASTERISK? IDENTIFIER PIPE
  209. PtrIndexPayload <- PIPE ASTERISK? IDENTIFIER (COMMA IDENTIFIER)? PIPE
  212. # Switch specific
  213. SwitchProng <- SwitchCase EQUALRARROW PtrPayload? AssignExpr
  215. SwitchCase
  216.     <- SwitchItem (COMMA SwitchItem)* COMMA?
  217.      / KEYWORD_else
  219. SwitchItem <- Expr (DOT3 Expr)?
  221. # Operators
  222. AssignOp
  223.     <- ASTERISKEQUAL
  224.      / SLASHEQUAL
  225.      / PERCENTEQUAL
  226.      / PLUSEQUAL
  227.      / MINUSEQUAL
  228.      / LARROW2EQUAL
  229.      / RARROW2EQUAL
  230.      / AMPERSANDEQUAL
  231.      / CARETEQUAL
  232.      / PIPEEQUAL
  233.      / ASTERISKPERCENTEQUAL
  234.      / PLUSPERCENTEQUAL
  235.      / MINUSPERCENTEQUAL
  236.      / EQUAL
  238. CompareOp
  239.     <- EQUALEQUAL
  240.      / EXCLAMATIONMARKEQUAL
  241.      / LARROW
  242.      / RARROW
  243.      / LARROWEQUAL
  244.      / RARROWEQUAL
  246. BitwiseOp
  247.     <- AMPERSAND
  248.      / CARET
  249.      / PIPE
  250.      / KEYWORD_orelse
  251.      / KEYWORD_catch Payload?
  253. BitShiftOp
  254.     <- LARROW2
  255.      / RARROW2
  257. AdditionOp
  258.     <- PLUS
  259.      / MINUS
  260.      / PLUS2
  261.      / PLUSPERCENT
  262.      / MINUSPERCENT
  264. MultiplyOp
  265.     <- PIPE2
  266.      / ASTERISK
  267.      / SLASH
  268.      / PERCENT
  269.      / ASTERISK2
  270.      / ASTERISKPERCENT
  272. PrefixOp
  273.     <- EXCLAMATIONMARK
  274.      / MINUS
  275.      / TILDE
  276.      / MINUSPERCENT
  277.      / AMPERSAND
  278.      / KEYWORD_try
  279.      / KEYWORD_await
  281. PrefixTypeOp
  282.     <- QUESTIONMARK
  283.      / KEYWORD_anyframe MINUSRARROW
  284.      / SliceTypeStart (ByteAlign / KEYWORD_const / KEYWORD_volatile / KEYWORD_allowzero)*
  285.      / PtrTypeStart (KEYWORD_align LPAREN Expr (COLON INTEGER COLON INTEGER)? RPAREN / KEYWORD_const / KEYWORD_volatile / KEYWORD_allowzero)*
  286.      / ArrayTypeStart
  288. SuffixOp
  289.     <- LBRACKET Expr (DOT2 (Expr? (COLON Expr)?)?)? RBRACKET
  290.      / DOT IDENTIFIER
  291.      / DOTASTERISK
  292.      / DOTQUESTIONMARK
  294. FnCallArguments <- LPAREN ExprList RPAREN
  296. # Ptr specific
  297. SliceTypeStart <- LBRACKET (COLON Expr)? RBRACKET
  299. PtrTypeStart
  300.     <- ASTERISK
  301.      / ASTERISK2
  302.      / LBRACKET ASTERISK (LETTERC / COLON Expr)? RBRACKET
  304. ArrayTypeStart <- LBRACKET Expr (COLON Expr)? RBRACKET
  306. # ContainerDecl specific
  307. ContainerDeclAuto <- ContainerDeclType LBRACE container_doc_comment? ContainerMembers RBRACE
  309. ContainerDeclType
  310.     <- KEYWORD_struct
  311.      / KEYWORD_opaque
  312.      / KEYWORD_enum (LPAREN Expr RPAREN)?
  313.      / KEYWORD_union (LPAREN (KEYWORD_enum (LPAREN Expr RPAREN)? / Expr) RPAREN)?
  315. # Alignment
  316. ByteAlign <- KEYWORD_align LPAREN Expr RPAREN
  318. # Lists
  319. IdentifierList <- (doc_comment? IDENTIFIER COMMA)* (doc_comment? IDENTIFIER)?
  321. SwitchProngList <- (SwitchProng COMMA)* SwitchProng?
  323. AsmOutputList <- (AsmOutputItem COMMA)* AsmOutputItem?
  325. AsmInputList <- (AsmInputItem COMMA)* AsmInputItem?
  327. StringList <- (STRINGLITERAL COMMA)* STRINGLITERAL?
  329. ParamDeclList <- (ParamDecl COMMA)* ParamDecl?
  331. ExprList <- (Expr COMMA)* Expr?
  333. # *** Tokens ***
  334. eof <- !.
  335. bin <- [01]
  336. bin_ <- '_'? bin
  337. oct <- [0-7]
  338. oct_ <- '_'? oct
  339. hex <- [0-9a-fA-F]
  340. hex_ <- '_'? hex
  341. dec <- [0-9]
  342. dec_ <- '_'? dec
  344. bin_int <- bin bin_*
  345. oct_int <- oct oct_*
  346. dec_int <- dec dec_*
  347. hex_int <- hex hex_*
  349. ox80_oxBF <- [\200-\277]
  350. oxF4 <- '\364'
  351. ox80_ox8F <- [\200-\217]
  352. oxF1_oxF3 <- [\361-\363]
  353. oxF0 <- '\360'
  354. ox90_0xBF <- [\220-\277]
  355. oxEE_oxEF <- [\356-\357]
  356. oxED <- '\355'
  357. ox80_ox9F <- [\200-\237]
  358. oxE1_oxEC <- [\341-\354]
  359. oxE0 <- '\340'
  360. oxA0_oxBF <- [\240-\277]
  361. oxC2_oxDF <- [\302-\337]
  363. # From https://lemire.me/blog/2018/05/09/how-quickly-can-you-check-that-a-string-is-valid-unicode-utf-8/
  364. # First Byte      Second Byte     Third Byte      Fourth Byte
  365. # [0x00,0x7F]
  366. # [0xC2,0xDF]     [0x80,0xBF]
  367. #    0xE0         [0xA0,0xBF]     [0x80,0xBF]
  368. # [0xE1,0xEC]     [0x80,0xBF]     [0x80,0xBF]
  369. #    0xED         [0x80,0x9F]     [0x80,0xBF]
  370. # [0xEE,0xEF]     [0x80,0xBF]     [0x80,0xBF]
  371. #    0xF0         [0x90,0xBF]     [0x80,0xBF]     [0x80,0xBF]
  372. # [0xF1,0xF3]     [0x80,0xBF]     [0x80,0xBF]     [0x80,0xBF]
  373. #    0xF4         [0x80,0x8F]     [0x80,0xBF]     [0x80,0xBF]
  375. mb_utf8_literal <-
  376.        oxF4      ox80_ox8F ox80_oxBF ox80_oxBF
  377.      / oxF1_oxF3 ox80_oxBF ox80_oxBF ox80_oxBF
  378.      / oxF0      ox90_0xBF ox80_oxBF ox80_oxBF
  379.      / oxEE_oxEF ox80_oxBF ox80_oxBF
  380.      / oxED      ox80_ox9F ox80_oxBF
  381.      / oxE1_oxEC ox80_oxBF ox80_oxBF
  382.      / oxE0      oxA0_oxBF ox80_oxBF
  383.      / oxC2_oxDF ox80_oxBF
  385. ascii_char_not_nl_slash_squote <- [\000-\011\013-\046-\050-\133\135-\177]
  387. char_escape
  388.     <- "\\x" hex hex
  389.      / "\\u{" hex+ "}"
  390.      / "\\" [nr\\t'"]
  391. char_char
  392.     <- mb_utf8_literal
  393.      / char_escape
  394.      / ascii_char_not_nl_slash_squote
  396. string_char
  397.     <- char_escape
  398.      / [^\\"\n]
  400. container_doc_comment <- ('//!' [^\n]* [ \n]*)+
  401. doc_comment <- ('///' [^\n]* [ \n]*)+
  402. line_comment <- '//' ![!/][^\n]* / '////' [^\n]*
  403. line_string <- ("\\\\" [^\n]* [ \n]*)+
  404. skip <- ([ \n] / line_comment)*
  406. CHAR_LITERAL <- "'" char_char "'" skip
  407. FLOAT
  408.     <- "0x" hex_int "." hex_int ([pP] [-+]? dec_int)? skip
  409.      /      dec_int "." dec_int ([eE] [-+]? dec_int)? skip
  410.      / "0x" hex_int [pP] [-+]? dec_int skip
  411.      /      dec_int [eE] [-+]? dec_int skip
  412. INTEGER
  413.     <- "0b" bin_int skip
  414.      / "0o" oct_int skip
  415.      / "0x" hex_int skip
  416.      /      dec_int   skip
  417. STRINGLITERALSINGLE <- "\"" string_char* "\"" skip
  418. STRINGLITERAL
  419.     <- STRINGLITERALSINGLE
  420.      / (line_string                 skip)+
  421. IDENTIFIER
  422.     <- !keyword [A-Za-z_] [A-Za-z0-9_]* skip
  423.      / "@\"" string_char* "\""                            skip
  424. BUILTINIDENTIFIER <- "@"[A-Za-z_][A-Za-z0-9_]* skip
  427. AMPERSAND            <- '&'      ![=]      skip
  428. AMPERSANDEQUAL       <- '&='               skip
  429. ASTERISK             <- '*'      ![*%=]    skip
  430. ASTERISK2            <- '**'               skip
  431. ASTERISKEQUAL        <- '*='               skip
  432. ASTERISKPERCENT      <- '*%'     ![=]      skip
  433. ASTERISKPERCENTEQUAL <- '*%='              skip
  434. CARET                <- '^'      ![=]      skip
  435. CARETEQUAL           <- '^='               skip
  436. COLON                <- ':'                skip
  437. COMMA                <- ','                skip
  438. DOT                  <- '.'      ![*.?]    skip
  439. DOT2                 <- '..'     ![.]      skip
  440. DOT3                 <- '...'              skip
  441. DOTASTERISK          <- '.*'               skip
  442. DOTQUESTIONMARK      <- '.?'               skip
  443. EQUAL                <- '='      ![>=]     skip
  444. EQUALEQUAL           <- '=='               skip
  445. EQUALRARROW          <- '=>'               skip
  446. EXCLAMATIONMARK      <- '!'      ![=]      skip
  447. EXCLAMATIONMARKEQUAL <- '!='               skip
  448. LARROW               <- '<'      ![<=]     skip
  449. LARROW2              <- '<<'     ![=]      skip
  450. LARROW2EQUAL         <- '<<='              skip
  451. LARROWEQUAL          <- '<='               skip
  452. LBRACE               <- '{'                skip
  453. LBRACKET             <- '['                skip
  454. LPAREN               <- '('                skip
  455. MINUS                <- '-'      ![%=>]    skip
  456. MINUSEQUAL           <- '-='               skip
  457. MINUSPERCENT         <- '-%'     ![=]      skip
  458. MINUSPERCENTEQUAL    <- '-%='              skip
  459. MINUSRARROW          <- '->'               skip
  460. PERCENT              <- '%'      ![=]      skip
  461. PERCENTEQUAL         <- '%='               skip
  462. PIPE                 <- '|'      ![|=]     skip
  463. PIPE2                <- '||'               skip
  464. PIPEEQUAL            <- '|='               skip
  465. PLUS                 <- '+'      ![%+=]    skip
  466. PLUS2                <- '++'               skip
  467. PLUSEQUAL            <- '+='               skip
  468. PLUSPERCENT          <- '+%'     ![=]      skip
  469. PLUSPERCENTEQUAL     <- '+%='              skip
  470. LETTERC              <- 'c'                skip
  471. QUESTIONMARK         <- '?'                skip
  472. RARROW               <- '>'      ![>=]     skip
  473. RARROW2              <- '>>'     ![=]      skip
  474. RARROW2EQUAL         <- '>>='              skip
  475. RARROWEQUAL          <- '>='               skip
  476. RBRACE               <- '}'                skip
  477. RBRACKET             <- ']'                skip
  478. RPAREN               <- ')'                skip
  479. SEMICOLON            <- ';'                skip
  480. SLASH                <- '/'      ![=]      skip
  481. SLASHEQUAL           <- '/='               skip
  482. TILDE                <- '~'                skip
  484. end_of_word <- ![a-zA-Z0-9_] skip
  485. KEYWORD_align       <- 'align'       end_of_word
  486. KEYWORD_allowzero   <- 'allowzero'   end_of_word
  487. KEYWORD_and         <- 'and'         end_of_word
  488. KEYWORD_anyframe    <- 'anyframe'    end_of_word
  489. KEYWORD_anytype     <- 'anytype'     end_of_word
  490. KEYWORD_asm         <- 'asm'         end_of_word
  491. KEYWORD_async       <- 'async'       end_of_word
  492. KEYWORD_await       <- 'await'       end_of_word
  493. KEYWORD_break       <- 'break'       end_of_word
  494. KEYWORD_callconv    <- 'callconv'    end_of_word
  495. KEYWORD_catch       <- 'catch'       end_of_word
  496. KEYWORD_comptime    <- 'comptime'    end_of_word
  497. KEYWORD_const       <- 'const'       end_of_word
  498. KEYWORD_continue    <- 'continue'    end_of_word
  499. KEYWORD_defer       <- 'defer'       end_of_word
  500. KEYWORD_else        <- 'else'        end_of_word
  501. KEYWORD_enum        <- 'enum'        end_of_word
  502. KEYWORD_errdefer    <- 'errdefer'    end_of_word
  503. KEYWORD_error       <- 'error'       end_of_word
  504. KEYWORD_export      <- 'export'      end_of_word
  505. KEYWORD_extern      <- 'extern'      end_of_word
  506. KEYWORD_fn          <- 'fn'          end_of_word
  507. KEYWORD_for         <- 'for'         end_of_word
  508. KEYWORD_if          <- 'if'          end_of_word
  509. KEYWORD_inline      <- 'inline'      end_of_word
  510. KEYWORD_noalias     <- 'noalias'     end_of_word
  511. KEYWORD_nosuspend   <- 'nosuspend'   end_of_word
  512. KEYWORD_noinline    <- 'noinline'    end_of_word
  513. KEYWORD_opaque      <- 'opaque'      end_of_word
  514. KEYWORD_or          <- 'or'          end_of_word
  515. KEYWORD_orelse      <- 'orelse'      end_of_word
  516. KEYWORD_packed      <- 'packed'      end_of_word
  517. KEYWORD_pub         <- 'pub'         end_of_word
  518. KEYWORD_resume      <- 'resume'      end_of_word
  519. KEYWORD_return      <- 'return'      end_of_word
  520. KEYWORD_linksection <- 'linksection' end_of_word
  521. KEYWORD_struct      <- 'struct'      end_of_word
  522. KEYWORD_suspend     <- 'suspend'     end_of_word
  523. KEYWORD_switch      <- 'switch'      end_of_word
  524. KEYWORD_test        <- 'test'        end_of_word
  525. KEYWORD_threadlocal <- 'threadlocal' end_of_word
  526. KEYWORD_try         <- 'try'         end_of_word
  527. KEYWORD_union       <- 'union'       end_of_word
  528. KEYWORD_unreachable <- 'unreachable' end_of_word
  529. KEYWORD_usingnamespace <- 'usingnamespace' end_of_word
  530. KEYWORD_var         <- 'var'         end_of_word
  531. KEYWORD_volatile    <- 'volatile'    end_of_word
  532. KEYWORD_while       <- 'while'       end_of_word
  534. keyword <- KEYWORD_align / KEYWORD_allowzero / KEYWORD_and / KEYWORD_anyframe
  535.          / KEYWORD_anytype / KEYWORD_asm / KEYWORD_async / KEYWORD_await
  536.          / KEYWORD_break / KEYWORD_callconv / KEYWORD_catch / KEYWORD_comptime
  537.          / KEYWORD_const / KEYWORD_continue / KEYWORD_defer / KEYWORD_else
  538.          / KEYWORD_enum / KEYWORD_errdefer / KEYWORD_error / KEYWORD_export
  539.          / KEYWORD_extern / KEYWORD_fn / KEYWORD_for / KEYWORD_if
  540.          / KEYWORD_inline / KEYWORD_noalias / KEYWORD_nosuspend / KEYWORD_noinline
  541.          / KEYWORD_opaque / KEYWORD_or / KEYWORD_orelse / KEYWORD_packed
  542.          / KEYWORD_pub / KEYWORD_resume / KEYWORD_return / KEYWORD_linksection
  543.          / KEYWORD_struct / KEYWORD_suspend / KEYWORD_switch / KEYWORD_test
  544.          / KEYWORD_threadlocal / KEYWORD_try / KEYWORD_union / KEYWORD_unreachable
  545.          / KEYWORD_usingnamespace / KEYWORD_var / KEYWORD_volatile / KEYWORD_while