48 lines
1.0 KiB
Markdown
48 lines
1.0 KiB
Markdown
# JSON Patch and Diff
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## Patches
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JSON Patch ([RFC 6902](https://tools.ietf.org/html/rfc6902)) defines a JSON document structure for expressing a sequence
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of operations to apply to a JSON document. With the `patch` function, a JSON Patch is applied to the current JSON value
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by executing all operations from the patch.
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??? example
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The following code shows how a JSON patch is applied to a value.
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```cpp
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--8<-- "examples/patch.cpp"
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```
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Output:
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```json
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--8<-- "examples/patch.output"
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```
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## Diff
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The library can also calculate a JSON patch (i.e., a **diff**) given two JSON values.
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!!! success "Invariant"
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For two JSON values *source* and *target*, the following code yields always true:
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```cüü
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source.patch(diff(source, target)) == target;
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```
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??? example
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The following code shows how a JSON patch is created as a diff for two JSON values.
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```cpp
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--8<-- "examples/diff.cpp"
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```
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Output:
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```json
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--8<-- "examples/diff.output"
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```
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