API reference

Everything exported by github.com/deltamesh/deltamesh as of v1.9.2.

Differ

func NewDiffer(c Codec, opts ...Option) *Differ
func (d *Differ) Diff(ctx context.Context, a, b io.Reader) (*Patch, error)
func (d *Differ) DiffTo(ctx context.Context, a, b io.Reader, w io.Writer) error

DiffTo never builds the patch in memory and is the right choice when the result is written straight to disk or to the network.

Applier

func NewApplier(c Codec, opts ...Option) *Applier
func (a *Applier) Apply(ctx context.Context, src io.Reader, p *Patch, dst io.Writer) error
func (a *Applier) Invert(p *Patch) (*Patch, error)

Codecs

Constructor	Handles	Notes
`JSON()`	RFC 8259 documents	Numbers preserved as written
`Proto(md)`	Protobuf messages	Requires a descriptor
`Arrow(schema)`	Record batches	Column-wise diffing
`NDJSON()`	Line-delimited JSON	Each line is a top-level entry

Error codes

Sentinel	Meaning	Retryable
`ErrTooDeep`	Nesting exceeded `WithMaxDepth`	No
`ErrMalformed`	Input is not valid for the codec	No
`ErrPathMissing`	Patch references a path absent from the source	No
`ErrVersionSkew`	Patch was produced by an incompatible major version	No
`ErrShortRead`	Underlying reader ended mid-value	Yes

All errors wrap the underlying cause, so errors.Is and errors.As work as expected.