aeson v0.8.1.0 Release Notes

    • Encoding a Scientific value with a huge exponent is now handled efficiently. (This would previously allocate a huge arbitrary-precision integer, potentially leading to a denial of service.)

    • Handling of strings that contain backslash escape sequences is greatly improved. For a pathological string containing almost a megabyte of consecutive backslashes, the new implementation is 27x faster and uses 42x less memory.

    • The ToJSON instance for UTCTime is rendered with higher (picosecond) resolution.

    • ๐Ÿ“œ The value parser now correctly handles leading whitespace.

    • ๐Ÿ†• New instances of ToJSON and FromJSON for Data.Sequence and Data.Functor.Identity. The Value type now has a Read instance.

    • ๐Ÿ“œ ZonedTime parser ordering now favours the standard JSON format, increasing efficiency in the common case.

    • ๐Ÿ— Encoding to a Text.Builder now escapes '<' and '>' characters, to reduce XSS risk.