You cannot select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
111 lines
3.5 KiB
Racket
111 lines
3.5 KiB
Racket
#lang br/ragg
|
|
|
|
;; Lua parser, adapted from:
|
|
;; http://www.lua.org/manual/5.1/manual.html#8
|
|
;;
|
|
|
|
|
|
chunk : (stat ["; "])* [laststat ["; "]]
|
|
|
|
block : chunk
|
|
|
|
stat : varlist "=" explist |
|
|
functioncall |
|
|
DO block END |
|
|
WHILE exp DO block END |
|
|
REPEAT block UNTIL exp |
|
|
IF exp THEN block (ELSEIF exp THEN block)* [ELSE block] END |
|
|
FOR NAME "=" exp "," exp ["," exp] DO block END |
|
|
FOR namelist IN explist DO block END |
|
|
FUNCTION funcname funcbody |
|
|
LOCAL FUNCTION NAME funcbody |
|
|
LOCAL namelist ["=" explist]
|
|
|
|
laststat : RETURN [explist] | BREAK
|
|
|
|
funcname : NAME ("." NAME)* [":" NAME]
|
|
|
|
varlist : var ("," var)*
|
|
|
|
var : NAME | prefixexp "[" exp "]" | prefixexp "." NAME
|
|
|
|
namelist : NAME ("," NAME)*
|
|
|
|
explist : (exp ",")* exp
|
|
|
|
|
|
;; Note by dyoo: The parsing of exp deviates from Lua in that we have these administrative
|
|
;; rules to explicitly represent the precedence rules.
|
|
;;
|
|
;; See: http://www.lua.org/manual/5.1/manual.html#2.5.6
|
|
;;
|
|
;; Ragg doesn't yet automatically desugar operator precedence rules.
|
|
;; I'm doing it by hand at the moment, which is not ideal, so a future version of
|
|
;; ragg will have a story about describing precedence.
|
|
;;
|
|
;; Operator precedence in Lua follows the table below, from lower to higher priority:
|
|
;;
|
|
;; or exp_1
|
|
;; and exp_2
|
|
;; < > <= >= ~= == exp_3
|
|
;; .. exp_4
|
|
;; + - exp_5
|
|
;; * / % exp_6
|
|
;; not # - (unary) exp_7
|
|
;; ^ exp_8
|
|
;;
|
|
;; As usual, you can use parentheses to change the precedences of an expression.
|
|
;; The concatenation ('..') and exponentiation ('^') operators are right associative.
|
|
;; All other binary operators are left associative.
|
|
;;
|
|
;; The original grammar rule before encoding precedence was:
|
|
;;
|
|
;; exp : NIL | FALSE | TRUE | NUMBER | STRING | "..." | function |
|
|
;; prefixexp | tableconstructor | exp binop exp | unop exp
|
|
|
|
exp : exp_1
|
|
exp_1: exp_1 binop_1 exp_2 | exp_2
|
|
exp_2: exp_2 binop_2 exp_3 | exp_3
|
|
exp_3: exp_3 binop_3 exp_4 | exp_4
|
|
exp_4: exp_5 binop_4 exp_4 | exp_5 ;; right associative
|
|
exp_5: exp_5 binop_5 exp_6 | exp_6
|
|
exp_6: exp_6 binop_6 exp_7 | exp_7
|
|
exp_7: unop exp_8
|
|
exp_8: exp_9 binop_8 exp_8 | exp_9 ;; right associative
|
|
exp_9: NIL | FALSE | TRUE | NUMBER | STRING | "..." | function |
|
|
prefixexp | tableconstructor
|
|
binop_1: OR
|
|
binop_2: AND
|
|
binop_3: "<" | ">" | "<=" | ">=" | "~=" | "=="
|
|
binop_4: ".."
|
|
binop_5: "+" | "-"
|
|
binop_6: "*" | "/" | "%"
|
|
binop_8: "^"
|
|
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
|
|
|
|
|
|
prefixexp : var | functioncall | "(" exp ")"
|
|
|
|
functioncall : prefixexp args | prefixexp ":" NAME args
|
|
|
|
args : "(" [explist] ")" | tableconstructor | STRING
|
|
|
|
function : FUNCTION funcbody
|
|
|
|
funcbody : "(" [parlist] ")" block END
|
|
|
|
parlist : namelist ["," "..."] | "..."
|
|
|
|
tableconstructor : "{" [fieldlist] "}"
|
|
|
|
fieldlist : field (fieldsep field)* [fieldsep]
|
|
|
|
field : "[" exp "]" "=" exp | NAME "=" exp | exp
|
|
|
|
fieldsep : "," | ";"
|
|
|
|
binop : "+" | "-" | "*" | "/" | "^" | "%" | ".." |
|
|
"<" | "<=" | ">" | ">=" | "==" | "~=" |
|
|
AND | OR
|
|
|
|
unop : "-" | NOT | "#" |