Language: Haskell
Introduction: These are I/O Haskell functions designed for two purposes: (1) to encrypt and decrypt text files using a caesar cipher and (2) to detect the language of a text file by comparing character frequency distributions.
Files: The files include language.hs, the primary file containing the functions. There is also encrypt.hs, used to encrypt files from the command line, decrypt.hs to decrypt, and guess_index.hs to determine the encryption index of an unknown encrypted file. This is done by building a dictionary of English words taken from three novels: Ulysses, Pride and Prejudice, and The Picture of Dorian Gray. The idea is that a file is considered decrypted when the cipher produces text with known English words from this dictionary. In addition, there is get_lang.hs which will tell you whether a language is likely written in English or in Portuguese based on chartacter frequency distribution.