Crate fionn_diff 

JSON Diff/Patch/Merge

High-performance JSON structural operations with SIMD acceleration.

This module provides three related capabilities:

JSON Diff

Generate a list of operations that transform one JSON document into another. Follows the spirit of RFC 6902 (JSON Patch) for the output format.

JSON Patch (RFC 6902)

Apply a sequence of operations to a JSON document:

• add: Insert a value at a path
• remove: Delete a value at a path
• replace: Replace a value at a path
• move: Move a value from one path to another
• copy: Copy a value from one path to another
• test: Verify a value equals the expected value

JSON Merge Patch (RFC 7396)

A simpler merge format where:

• Objects are recursively merged
• null values indicate deletion
• Other values replace existing ones

Performance

Uses SIMD acceleration for:

• Bulk string comparison (detect unchanged strings quickly)
• Array element comparison
• Finding longest common subsequence in arrays

Structs

CellChange

Change to a single cell

CsvDiff

Result of CSV diff

CsvDiffOptions

CSV diff options

CsvDiffStats

Statistics about a CSV diff

DiffOptions

Options for diff generation.

GenericDiffOptions

Options for diff computation

GenericPatch

A collection of patch operations (format-agnostic)

JsonPatch

A JSON Patch document (sequence of operations).

JsonPatchRef

A JSON Patch document with zero-copy operations.

StreamingMergeOptions

Options for streaming merge operations

TapeDiff

Result of diffing two tapes

TapeDiffOptions

Options for tape diff

Enums

CsvDiffOp

A single CSV diff operation

DiffValueKind

Classification of value types for diff operations

GenericPatchError

Errors that can occur during patch application

GenericPatchOperation

A single patch operation (format-agnostic)

PatchError

Error type for patch operations.

PatchOperation

A single patch operation.

PatchOperationRef

A single patch operation with zero-copy paths where possible.

RowIdentityMode

How rows are identified for diff comparison

TapeDiffOp

A tape diff operation

TapeValueOwned

Owned tape value for patch operations

Traits

DiffableValue

Trait for values that can be compared for diffing

Patchable

Trait for values that can have patches applied

Functions

apply_patch

Apply a JSON Patch to a value, returning a new value.

apply_patch_mut

Apply a JSON Patch to a value in place.

apply_tape_diff

Apply a TapeDiff to a mutable value

csv_diff

Compute diff between two CSV representations

csv_diff_tapes

Compute diff between two TapeSource CSVs

deep_merge

Deep merge two objects, preferring values from overlay.

deep_merge_tape_into_value

Deep merge a tape onto an existing Value

deep_merge_tapes

Deep merge two tapes (preserves null values)

diff_tapes

Diff two tapes and produce a patch

diff_tapes_with_options

Diff two tapes with custom options

generic_apply_operation

Apply a single operation to a value

generic_apply_patch

Apply a patch to a value

generic_compute_diff

Compute a diff between two values

generic_compute_diff_with_options

Compute a diff with custom options

json_diff

Generate a JSON Patch that transforms source into target.

json_diff_with_options

Generate a JSON Patch with custom options.

json_diff_zerocopy

Generate a zero-copy JSON Patch that transforms source into target.

json_merge_patch

Apply a JSON Merge Patch (RFC 7396) to a document.

json_numbers_equal

Compare two JSON number representations for equality.

json_strings_equal

Compare two JSON string values for equality.

merge_many

Merge multiple JSON documents using merge patch semantics.

merge_many_tapes

Merge multiple tapes left-to-right using RFC 7396 semantics

merge_patch_to_value

Generate a merge patch from two JSON documents.

merge_tape_into_value

Merge a tape onto an existing Value

merge_tapes

Merge two tapes using RFC 7396 (JSON Merge Patch) semantics

patch_tape

Full pipeline: apply diff from tape_b to value derived from tape_a

simd_bytes_equal

SIMD-accelerated byte slice equality check.

simd_find_first_difference

Find the first position where two byte slices differ.

streaming_merge

Streaming merge that can be interrupted/resumed

tape_to_value

Convert a tape to a serde_json::Value

three_way_patch

Three-way patch: apply diff to a tape and return as Value

value_to_json

Serialize a value back to JSON string

value_to_json_pretty

Serialize a value back to pretty JSON string