| octal | Text.Parsec.Token, Text.ParserCombinators.Parsec.Token | 
| octDigit | Text.Parsec.Char, Text.Parsec, Text.ParserCombinators.Parsec.Char, Text.ParserCombinators.Parsec | 
| Ok | Text.Parsec.Prim, Text.Parsec | 
| oneOf | Text.Parsec.Char, Text.Parsec, Text.ParserCombinators.Parsec.Char, Text.ParserCombinators.Parsec | 
| Operator |  | 
| 1 (Type/Class) | Text.Parsec.Expr | 
| 2 (Type/Class) | Text.ParserCombinators.Parsec.Expr | 
| operator | Text.Parsec.Token, Text.ParserCombinators.Parsec.Token | 
| OperatorTable |  | 
| 1 (Type/Class) | Text.Parsec.Expr | 
| 2 (Type/Class) | Text.ParserCombinators.Parsec.Expr | 
| opLetter | Text.Parsec.Token, Text.ParserCombinators.Parsec.Language, Text.ParserCombinators.Parsec.Token | 
| opStart | Text.Parsec.Token, Text.ParserCombinators.Parsec.Language, Text.ParserCombinators.Parsec.Token | 
| option | Text.Parsec.Combinator, Text.Parsec, Text.ParserCombinators.Parsec.Combinator, Text.ParserCombinators.Parsec | 
| optional | Text.Parsec.Combinator, Text.Parsec, Text.ParserCombinators.Parsec.Combinator, Text.ParserCombinators.Parsec | 
| optionMaybe | Text.Parsec.Combinator, Text.Parsec, Text.ParserCombinators.Parsec.Combinator, Text.ParserCombinators.Parsec |