LanguageDef：nestedComments

everyday parser Parsec 
Prelude> :m Text.ParserCombinators.Parsec.Language
Prelude Text.ParserCombinators.Parsec.Language> nestedComments haskellStyle
Loading package parsec ... linking ... done.
True
Prelude Text.ParserCombinators.Parsec.Language> nestedComments javaStyle
True
Prelude Text.ParserCombinators.Parsec.Language> nestedComments emptyDef
True
Prelude Text.ParserCombinators.Parsec.Language> nestedComments haskellDef
True
Prelude Text.ParserCombinators.Parsec.Language> nestedComments mondrianDef
True