CalculatingProteinMass.hs

import qualified Bioinformatics.Protein as P
import qualified Data.Map as M

calculateProteinMass :: P.Protein -> Double
calculateProteinMass ps =
  let masses = map getValue ps
      getValue aa = maybe 0.0 id (M.lookup aa P.monoisotopicMasses)
  in sum masses

main = do
  aas <- getLine
  putStrLn . show . calculateProteinMass $ map P.charToAminoAcid aas