Buzz Syntax BNF Specification

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An identifier in Buzz is any sequence of alphanumeric characters starting with a letter or an underscore (_). The recognized tokens are:

Token	Id
_identifier_	`TOKID`
_numeric constant_	`TOKCONST`
'_string_' `“`_string_`”`	`TOKSTRING`
`var`	`TOKVAR`
`nil`	`TOKNIL`
`if`	`TOKIF`
`else`	`TOKELSE`
`function`	`TOKFUN`
`return`	`TOKRETURN`
`for`	`TOKFOR`
`while`	`TOKWHILE`
`and`, `or`	`TOKANDOR`
`not`	`TOKNOT`
`+`, `-`	`TOKADDSUB`
`*`, `/`	`TOKMULDIV`
`%`	`TOKMOD`
`^`	`TOKPOW`
`{`	`TOKBLOCKOPEN`
`}`	`TOKBLOCKCLOSE`
`(`	`TOKPAROPEN`
`)`	`TOKPARCLOSE`
`[`	`TOKIDXOPEN`
`]`	`TOKIDXCLOSE`
`;` `\n`	`TOKSTATEND`
`,`	`TOKLISTSEP`
`=`	`TOKASSIGN`
`.`	`TOKDOT`
`<` `⇐` `>` `>=` `==` `!=`	`TOKCMP`

  script             ::= statlist

  statlist           ::= stat | statlist stat
  stat               ::= <nil> | vardef | fundef | if | loop | command

  block              ::= TOKBLOCKOPEN statlist TOKBLOCKCLOSE

  vardef             ::= TOKVAR TOKID | TOKVAR TOKID assignment
  fundef             ::= TOKFUN TOKID TOKPAROPEN idlist TOKPARCLOSE block
  if                 ::= TOKIF TOKPAROPEN condition TOKPARCLOSE block endif
  endif              ::= <nil> |  TOKELSE block
  loop               ::= forloop | whileloop
  forloop            ::= TOKFOR TOKPAROPEN idref TOKASSIGN expression TOKLISTSEP
                         condition TOKLISTSEP idref TOKASSIGN expression TOKPARCLOSE block
  whileloop          ::= TOKWHILE TOKPAROPEN condition TOKPARCLOSE block

  conditionlist      ::= condition | conditionlist TOKLISTSEP condition
  condition          ::= comparison | condition TOKANDOR comparison
  comparison         ::= TOKPAROPEN condition TOKPARCLOSE | NOT comparison | expression | expression TOKCMP expression

  expression         ::= product | expression TOKADDSUB product
  product            ::= modulo | product TOKMULDIV modulo
  modulo             ::= power | modulo TOKMOD power
  power              ::= operand powerrest
  powerrest          ::= <nil> | TOKPOW power
  operand            ::= TOKNIL | TOKBLOCKOPEN assignmentlist TOKBLOCKCLOSE | TOKCONST | TOKSTRING | TOKPAROPEN expression TOKPARCLOSE | TOKADDSUB power | idref | lambda

  command            ::= idref | idref assignment | TOKRETURN expression
  assignment         ::= TOKASSIGN expression
  assignmentlist     ::= <nil> | idref assignment | assignmentlist TOKLISTSEP idref assignment

  idlist             ::= <nil> | TOKID | idlist TOKLISTSEP TOKID
  idreflist          ::= idref | idreflist TOKLISTSEP idref
  idref              ::= TOKID | idref TOKDOT TOKID | idref TOKIDXOPEN expression TOKIDXCLOSE | idref TOKPAROPEN conditionlist TOKPARCLOSE

  lambda             ::= TOKFUN TOKPAROPEN idlist TOKPARCLOSE block

Buzz Syntax BNF Specification

Tokens

Grammar

The Buzz Language