module Fun.Syntax where

import           Data.Either
import           Fun.Tree

data SyntaxError = SyntaxError String

syntaxBlock :: Block -> Either [SyntaxError] Block
syntaxBlock (FunctionBlock decl defns) = Right $ FunctionBlock decl defns

mergeSyntax :: [Either [SyntaxError] a] -> ([a] -> b) -> Either [SyntaxError] b
mergeSyntax d c = case any isLeft d of
  True  -> Left $ concat $ lefts d
  False -> Right $ c $ rights d

syntaxProgram :: Program -> Either [SyntaxError] Program
syntaxProgram (Program blocks) = mergeSyntax (map syntaxBlock blocks) Program

syntaxTree :: Tree -> Either [SyntaxError] Tree
syntaxTree (Tree programs) = mergeSyntax (map syntaxProgram programs) Tree