-- Hoogle documentation, generated by Haddock
-- See Hoogle, http://www.haskell.org/hoogle/


-- | Convert between different Haskell syntax trees.
--   
--   Provides an instance that translates haskell-src-exts expression trees
--   into Template Haskell expression trees in a way that depends only on
--   the haskell-src-exts syntax tree and agreement on the pretty-printed
--   representation of Haskell between haskell-src-exts pretty-printer and
--   Template Haskell quotations (as opposed to depending on both TH and
--   haskell-src-exts syntax tree representations).
--   
--   Instead of converting between data types, haskell-src-exts syntax
--   trees are pretty-printed and wrapped in a TH quotation which is then
--   interpreted as a Haskell program, yielding a TH Exp tree. Free
--   variables in the haskell-src-exts tree are preserved by lifting them
--   to TH splices prior to pretty-printing.
@package syntax-trees
@version 0.1

module Language.Haskell.SyntaxTrees.Main
type Witness a = a
class Translation s t
translateTree :: (Translation s t) => s -> Either s t
parseToTarget :: (Translation s t) => Witness s -> String -> Either String t


-- | Provides an instance that translates haskell-src-exts expression trees
--   into Template Haskell expression trees in a way that depends only on
--   the haskell-src-exts syntax tree and agreement on the pretty-printed
--   representation of Haskell between haskell-src-exts pretty-printer and
--   Template Haskell quotations (as opposed to depending on both TH and
--   haskell-src-exts syntax tree representations).
--   
--   Instead of converting between data types, haskell-src-exts syntax
--   trees are pretty-printed and wrapped in a TH quotation which is then
--   interpreted as a Haskell program, yielding a TH Exp tree. Free
--   variables in the haskell-src-exts tree are preserved by lifting them
--   to TH splices prior to pretty-printing.
--   
--   e.g. <tt>parseToTH "let x = 1 in x + y"</tt> = <tt> Right (LetE [ValD
--   (VarP x_1) (NormalB (LitE (IntegerL 1))) []] (InfixE (Just (VarE x_1))
--   (VarE GHC.Num.+) (Just (VarE y)))) </tt>
module Language.Haskell.SyntaxTrees.ExtsToTH

-- | Translate a Language.Haskell.Exts.Exp (haskell-src-exts) syntax tree
--   to a Language.Haskell.TH.Exp (template-haskell) syntax tree
translateExtsToTH :: Exp -> Either Exp Exp

-- | Parse a string to a Language.Haskell.TH.Exp (template-haskell)
--   expression via intermediate representation as a Exts.Exp tree.
parseToTH :: String -> Either String Exp

-- | Parse a string to a tree of type <tt>t</tt>, via intermediate
--   representation as a tree of type <tt>s</tt>. Requires a witness of the
--   intermediate type <tt>s</tt> to be passed as the first argument.
--   
--   If parsing fails then <tt>parseToTarget s = Left s</tt>, otherwise
--   <tt>parseToTarget s = Right t</tt> where <tt>t</tt> is the parsed
--   tree.
parseToTarget :: (Translation s t) => Witness s -> String -> Either String t

-- | Translate a tree of type <tt>s</tt> to a tree of type <tt>t</tt>.
--   
--   If translation fails then <tt>translate s = Left s</tt>, otherwise
--   <tt>translate s = Right t</tt> where <tt>t</tt> is the translated
--   tree.
translateTree :: (Translation s t) => s -> Either s t
instance Show NestedScopes
instance Translation Exp Exp

module Language.Haskell.SyntaxTrees