Pre-parsing.

This is the skeleton from before we started to write the parser.

You can start from here if you want to play around with writing
your own calculator.

1 files changed, 16 insertions, 0 deletions

diff --git a/calculator.hs b/calculator.hs
new file mode 100644
index 0000000..7753022
--- /dev/null
+++ b/calculator.hs
@@ -0,0 +1,16 @@
+import Text.Parsec
+import Text.Parsec.String
+
+calculation :: Parser Int
+calculation = return undefined
+
+calculate :: String -> String
+calculate s =
+  case ret of
+    Left e -> "error: " ++ (show e)
+    Right n -> "answer: " ++ (show n)
+  where
+    ret = parse calculation "" s
+
+main :: IO ()
+main = interact (unlines . (map calculate) . lines)