JavaletteLight.hs

{-# LANGUAGE QuasiQuotes #-}

module JavaletteLight where

import Language.LBNF

{- compile is a TH function and cf is a QuasiQuoter for LBNF. 
compile will generate most of the code that BNFC, Happy and Alex 
would (and some new stuff) and splice it directly into this module. 
-}
compile [$cf|

-- This is a new pragma. The rest of the grammar is original JL.
antiquote "[" ":" ":]" ;

-- Javalette Light: a simple subset of C, covering
-- programs with a single zero-argument function.
-- example: koe.jll
-- ordinary rules

Fun.      Prog     ::= Typ Ident "(" ")" "{" [Stm] "}" ;

SDecl.    Stm      ::= Typ Ident ";"  ;
SAss.     Stm      ::= Ident "=" Exp ";"  ;
SIncr.    Stm      ::= Ident "++" ";"  ;
SWhile.   Stm      ::= "while" "(" Exp ")" "{" [Stm] "}" ;

ELt.      Exp0     ::= Exp1 "<" Exp1 ;
EPlus.    Exp1     ::= Exp1 "+" Exp2 ;
ETimes.   Exp2     ::= Exp2 "*" Exp3 ;
EVar.     Exp3     ::= Ident ;
EInt.     Exp3     ::= Integer ;
EDouble.  Exp3     ::= Double ;

[].       [Stm]    ::= ;
(:).      [Stm]    ::= Stm [Stm] ;

-- coercions

_.        Stm      ::= Stm ";" ;

_.  Exp      ::= Exp0 ;
_.  Exp0     ::= Exp1 ;
_.  Exp1     ::= Exp2 ;
_.  Exp2     ::= Exp3 ;
_.  Exp3     ::= "(" Exp ")" ;

TInt.     Typ  ::= "int" ;
TDouble.  Typ  ::= "double" ;

-- pragmas

comment "/*" "*/" ;
comment "//" ;

entrypoints Prog, Stm, Exp ;
  |]