This release adds much more detailed errors, support for the toml.Marshaler interface, and several fixes.

There is no special meaning in the jump to v1.0; the 0.x releases were always treated as if they're 1.x with regards to compatibility; the versioning scheme for this library predates the release of modules.

New features

• Error reporting is much improved; the reported position of errors should now always be correct and the library can print more detailed errors (#299, #332)

  Decode always return a toml.ParseError, which has three methods:

  • Error() behaves as before and shows a single concise line with the error.

  • ErrorWithPosition() shows the same error, but also shows the line the error occurred at, similar to e.g. clang or the Rust compiler.

  • ErrorWithUsage() is the same as ErrorWithPosition(), but may also show a longer usage guidance message. This isn't always present (in which case it behaves identical to ErrorWithPosition()), but it should be present for most common mistakes and sources of confusion.

  Which error the correct one to use is depends on your application and preferences; in general I would recommend using at least ErrorWithPosition() for user-facing errors, as it's much more helpful for users of any skill level. If your users are likely to be non-technical then ErrorWithUsage() is probably a good idea; I did my best to avoid technical jargon such as "newline" and phrase things in a way that's understandable by most people not intimately familiar with these sort of things.

  Additionally, the TOML key that fialed should now always be reported in all errors.

• Add toml.Marshaler interface. This can be used if you want full control over how something is marshalled as TOML, similar to json.Marshaler etc. This takes precedence over encoding.TextMarshaler. (#327)

• Allow TOML integers to be decoded to a Go float (#325)

  Previously int = 42 could only be decoded to an int* type; now this can also be decoded in a float type as long as it can be represented without loss of data.

Fixes

• Key.String() is now quoted when needed (#333)

• Fix decoding of nested structs on 32bit platforms (#314)

• Empty slices are now always []T{} rather than nil, which was the behaviour in v0.3.1 and before. While they are identical for most purposes, encoding/json encodes them different ([] vs. null), making it an (accidentally) incompatible change (#339)