rlox/grammar.org

statement -> print_statement

return_statement

break_statement

block_statement

var_statement

if_statement

while_statement

for_statement

expression_statement

print_statement -> "print" expression ";" return_statement -> "return" expression? ";" break_statement -> "break" ";" block_statement -> "do" statement* "end" expression_statement -> expression ";"?

; leading "var" optional; the ":" is required var_statement -> "var"? IDENTIFIER ":" IDENTIFIER? ( variable_declaration

function_declaration

struct_declaration ) ; struct = WIP

variable_declaration -> ( "=" expression )? ";" function_declaration -> ":" "fn" "(" parameters? ")" ( "{" expression "}" )? statement parameters -> IDENTIFIER ( ":" IDENTIFIER )? ( "," IDENTIFIER ( ":" IDENTIFIER )? )*

if_statement -> "if" expression "then" statement ( "elif" expression "then" statement )* ( "else" statement )? while_statement -> "while" expression statement for_statement -> "for" var_statement expression ";" expression_statement statement

; ———- expressions (lowest -> highest precedence) ———- expression -> assignment assignment -> IDENTIFIER "=" assignment ; right-associative

pipe

pipe -> logic ( "|>" logic )* ; left-assoc; x |> f(a) == f(x, a) logic -> is ( ( "or" | "and" ) is )* is -> equality ( "is" equality )* equality -> comparison ( ( "=" | "!" ) comparison )* comparison -> term ( ( ">" | ">=" | "<" | "<=" ) term )* term -> factor ( ( "+" | "-" ) factor )* factor -> unary ( ( "" | "/" ) unary ) unary -> ( "!" | "-" ) unary | call call -> primary ( "(" arguments? ")" )* arguments -> expression ( "," expression )* primary -> NUMBER | STRING | "true" | "false" | "nil"

"(" expression ")"	IDENTIFIER
dictionary	list	ATOM ; WIP

; ———- work in progress (lexed; parser support being added) ———- struct_declaration -> "struct" "{" field* "}" field -> IDENTIFIER ( ":" IDENTIFIER )? ";" dictionary -> "dict" "(" IDENTIFIER ":" expression ( "," IDENTIFIER ":" expression )* ")" list -> "list" "(" expression ( "," expression )* ")"