1 files changed, 20 insertions, 0 deletions
diff --git a/src/Fun/Syntax.hs b/src/Fun/Syntax.hs
new file mode 100644
index 0000000..ab17215
--- /dev/null
+++ b/src/Fun/Syntax.hs
@@ -0,0 +1,20 @@
+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