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rlp/src/Core/Parse.y

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-- TODO: resolve shift/reduce conflicts
{
module Core.Parse
( parseCore
, parseCoreExpr
, module Core.Lex -- temp convenience
, parseTmp
)
where
import Data.Foldable (foldl')
import Core.Syntax
import Core.Lex
import Compiler.RLPC
}
%name parseCore Module
%name parseCoreExpr Expr
%tokentype { CoreToken }
%error { parseError }
%monad { RLPC }
%token
let { TokenLet }
letrec { TokenLetrec }
module { TokenModule }
where { TokenWhere }
',' { TokenComma }
in { TokenIn }
litint { TokenLitInt $$ }
varname { TokenVarName $$ }
varsym { TokenVarSym $$ }
conname { TokenConName $$ }
consym { TokenConSym $$ }
'λ' { TokenLambda }
'->' { TokenArrow }
'=' { TokenEquals }
'(' { TokenLParen }
')' { TokenRParen }
'{' { TokenLBrace }
'}' { TokenRBrace }
';' { TokenSemicolon }
eof { TokenEOF }
%%
Module :: { Module }
Module : module conname where Program Eof { Module (Just ($2, [])) $4 }
| Program Eof { Module Nothing $1 }
Eof :: { () }
Eof : eof { () }
| error { () }
Program :: { Program }
Program : '{' ScDefs Close { Program $2 }
ScDefs :: { [ScDef] }
ScDefs : ScDef ';' ScDefs { $1 : $3 }
| {- epsilon -} { [] }
ScDef :: { ScDef }
ScDef : Var ParList '=' Expr { ScDef $1 $2 $4 }
ParList :: { [Name] }
ParList : Var ParList { $1 : $2 }
| {- epsilon -} { [] }
Expr :: { Expr }
Expr : let '{' Bindings Close in Expr { Let NonRec $3 $6 }
| letrec '{' Bindings Close in Expr { Let Rec $3 $6 }
| 'λ' Binders '->' Expr { Lam $2 $4 }
| Application { $1 }
| Expr1 { $1 }
Close :: { () }
Close : '}' { () }
| error { () }
Binders :: { [Name] }
Binders : Var Binders { $1 : $2 }
| Var { [$1] }
Application :: { Expr }
Application : Expr1 AppArgs { foldl' App $1 $2 }
-- TODO: Application can probably be written as a single rule, without AppArgs
AppArgs :: { [Expr] }
AppArgs : Expr1 AppArgs { $1 : $2 }
| Expr1 { [$1] }
Expr1 :: { Expr }
Expr1 : litint { IntE $1 }
| Id { Var $1 }
| '(' Expr ')' { $2 }
Bindings :: { [Binding] }
Bindings : Binding ';' Bindings { $1 : $3 }
| Binding ';' { [$1] }
| Binding { [$1] }
Binding :: { Binding }
Binding : Var '=' Expr { $1 := $3 }
Id :: { Name }
Id : Var { $1 }
| Con { $1 }
Var :: { Name }
Var : '(' varsym ')' { $2 }
| varname { $1 }
Con :: { Name }
Con : '(' consym ')' { $2 }
| conname { $1 }
{
parseError :: [CoreToken] -> a
parseError ts = error $ "parse error at token: " <> show (head ts)
parseTmp :: IO (Module)
parseTmp = do
s <- readFile "/tmp/t.hs"
case lexCore' s >>= runRLPC . parseCore of
Left e -> error e
Right a -> pure a
}