diff options
Diffstat (limited to 'src/Helper.hs')
| -rw-r--r-- | src/Helper.hs | 23 |
1 files changed, 22 insertions, 1 deletions
diff --git a/src/Helper.hs b/src/Helper.hs index 5433dd0..0c2b576 100644 --- a/src/Helper.hs +++ b/src/Helper.hs @@ -6,6 +6,7 @@ module Helper where import qualified Control.Monad.State as S +import Data.Array import qualified Data.BitString as Bit import qualified Data.ByteString as Byte import qualified Data.ByteString.Char8 as C @@ -35,9 +36,10 @@ printContext (Context inp path) = p $ lines inp errPrefix :: String errPrefix = "\ESC[41mERROR\ESC[0m " -data Error = SyntaxError String | UndefinedIdentifier Identifier | InvalidIndex Int | FailedTest Expression Expression Expression Expression | ContextualError Error Context | ImportError String +data Error = SyntaxError String | UndefinedIdentifier Identifier | InvalidIndex Int | FailedTest Expression Expression Expression Expression | ContextualError Error Context | SuggestSolution Error String | ImportError String instance Show Error where show (ContextualError err ctx) = show err <> "\n" <> (printContext ctx) + show (SuggestSolution err sol) = show err <> "\nPerhaps you meant: " <> sol show (SyntaxError err) = errPrefix <> "invalid syntax\n\ESC[45mnear\ESC[0m " <> err show (UndefinedIdentifier ident) = @@ -211,6 +213,25 @@ decodeStdout e = do --- +-- from reddit u/cgibbard +levenshtein :: (Eq a) => [a] -> [a] -> Int +levenshtein xs ys = levMemo ! (n, m) + where + levMemo = + array ((0, 0), (n, m)) [ ((i, j), lev i j) | i <- [0 .. n], j <- [0 .. m] ] + n = length xs + m = length ys + xa = listArray (1, n) xs + ya = listArray (1, m) ys + lev 0 v = v + lev u 0 = u + lev u v + | xa ! u == ya ! v = levMemo ! (u - 1, v - 1) + | otherwise = 1 + minimum + [levMemo ! (u, v - 1), levMemo ! (u - 1, v), levMemo ! (u - 1, v - 1)] + +--- + -- TODO: Performanize matchingFunctions :: Expression -> Environment -> String matchingFunctions e (Environment env) = |