Add "SimpleT" t output form

This new output form allows easy piping to the decode function of the
tricu executable. Includes a new test for roundtrip evaluation of map,
compilation to tree calculus terms, and decoding back to a human
readable string.

src/Main.hs

@@ -1,13 +1,13 @@
 module Main where
 
 import Compiler
-import Eval     (evalTricu, result, toAST)
-import Library  (library)
-import Parser   (parseTricu)
+import Eval                   (evalTricu, result)
+import Library                (library)
+import Parser                 (parseTricu)
 import REPL
 import Research
 
-import Text.Megaparsec (runParser)
+import Text.Megaparsec        (runParser)
 import System.Console.CmdArgs
 
 import qualified Data.Map as Map
@@ -18,9 +18,6 @@ data TricuArgs
   | Decode { input :: Maybe FilePath }
   deriving (Show, Data, Typeable)
 
-data CompiledForm = TreeCalculus | AST | Ternary | Ascii
-  deriving (Show, Data, Typeable)
-
 replMode :: TricuArgs
 replMode = Repl
   &= help "Start interactive REPL"
@@ -33,8 +30,8 @@ compileMode = Compile
       &= help "Relative or absolute path to file input for compilation" &= name "f"
   , output = def &= typ "OUTPUT" 
       &= help "Optional output file path for resulting output" &= name "o"
-  , form = TreeCalculus &= typ "FORM" 
-      &= help "Output form: (tree|ast|ternary|ascii)" 
+  , form = FSL &= typ "FORM" 
+      &= help "Output form: (fsl|tree|ast|ternary|ascii)" 
       &= name "t"
   }
   &= help "Compile a file and return the result of the expression in the final line"
@@ -75,9 +72,3 @@ main = do
         Just inputPath -> readFile inputPath
         Nothing -> getContents
       putStrLn $ decodeResult $ result $ evalTricu library $ parseTricu value
-
-formatResult :: CompiledForm -> T -> String
-formatResult TreeCalculus = show
-formatResult AST          = show . toAST
-formatResult Ternary      = toTernaryString
-formatResult Ascii        = toAscii