BNF → tree-sitter cheat sheet

BNF	tree-sitter JS	Notes
`name -> body ;`	`name: $ => body`	Rule definition
`a b c`	`seq(a, b, c)`	Sequence
`a \\| b \\| c`	`choice(a, b, c)`	Alternatives
`x*`	`repeat(x)`	Zero or more
`x+`	`repeat1(x)`	One or more
`x?`	`optional(x)`	Zero or one
`(body)`	inline group	No new rule created
`'text'`	`'text'`	Literal string
`/regex/`	`/regex/`	Pattern
`<< body >>`	`token(body)`	Atomic lexer token
`<<! body >>`	`token.immediate(body)`	Immediate token (no leading whitespace)
`label: sym`	`field('label', sym)`	Named AST field
`(body => name)`	`alias(body, $.name)`	Named alias
`(body => 'str')`	`alias(body, 'str')`	Anonymous alias
`body %prec N`	`prec(N, body)`	Precedence
`body %prec.left N`	`prec.left(N, body)`	Left-associative precedence
`body %prec.right N`	`prec.right(N, body)`	Right-associative precedence
`body %prec.dynamic N`	`prec.dynamic(N, body)`	Dynamic precedence
`%axiom r`	(emits `r` first in `rules:`)	Explicit start rule
`%conflicts [r1, r2]`	`conflicts: $ => [[$.r1, $.r2]]`	Conflict declaration
`%inline r`	`inline: $ => [$.r]`	Inline rule
`%supertypes r`	`supertypes: $ => [$.r]`	Supertype declaration
`%extras /x/, r`	`extras: $ => [/x/, $.r]`	Extra tokens
`%include "f.bnf"`	(merges the file’s rules and directives)	File inclusion
`# comment`	(removed)	Line comment