feat: impl init jsonpatch module

jsonpatch/README.md

@@ -0,0 +1,47 @@
+## Introduction
+
+`jsonpatch` is a module for applying JSON patches (RFC 6902) for KCL values.
+
+TODO: more jsonpatch actions including "add", "remove", "move", etc.
+
+## How to Use
+
++ Add the dependency
+
+```shell
+kcl mod add jsonpatch
+```
+
++ Write the code
+
+```python
+import jsonpatch
+
+data = {
+    "firstName": "John",
+    "lastName": "Doe",
+    "age": 30,
+    "address": {
+        "streetAddress": "1234 Main St",
+        "city": "New York",
+        "state": "NY",
+        "postalCode": "10001"
+    },
+    "phoneNumbers": [
+        {
+            "type": "home",
+            "number": "212-555-1234"
+        },
+        {
+            "type": "work",
+            "number": "646-555-5678"
+        }
+    ]
+}
+phoneNumbers0type = jsonpatch.get_obj(data, "phoneNumbers/0/type")
+newObj = jsonpatch.set_obj(data, "phoneNumbers/0/type", "school")
+```
+
+## Resource
+
+The code source and documents are [here](https://github.com/kcl-lang/artifacthub/tree/main/jsonpatch)

jsonpatch/kcl.mod

@@ -0,0 +1,5 @@
+[package]
+name = "jsonpatch"
+version = "0.0.1"
+description = "`jsonpatch` is a module for applying JSON patches (RFC 6902) for KCL values."
+

jsonpatch/main.k

@@ -0,0 +1,119 @@
+type PatchOperationType = "add" | "remove" | "replace" | "move" | "test" | "copy"
+KCL_BUILTIN_TYPES = ["int", "str", "bool", "float", "NoneType", "UndefinedType", "any", "list", "dict", "function", "number_multiplier"]
+NULL_CONSTANTS = [Undefined, None]
+
+schema Patch:
+    op: PatchOperationType
+    path: str
+    value?: any
+
+type JsonPatch = [Patch]
+
+get_obj = lambda obj: any, path: str -> any {
+    elements = path.lstrip('/').split('/')
+    _get_obj_n(obj, elements, 0)
+}
+
+get_obj_by_key = lambda obj: any, key: str -> any {
+    result = Undefined
+    ty = typeof(obj)
+    # Schema
+    if ty not in KCL_BUILTIN_TYPES:
+        result = obj[key]
+    # Config
+    elif ty == "dict":
+        result = obj[key]
+    # List
+    elif ty == "list":
+        idx = _get_list_index_from_key(key)
+        if idx not in NULL_CONSTANTS:
+            result = obj[idx]
+    result
+}
+
+_get_list_index_from_key = lambda key: str -> int {
+    result = Undefined
+    if key == "-":
+        result = -1
+    elif key.startswith("-") and key[1:].isdigit():
+        result = -int(key)
+    elif key.isdigit():
+        result = int(key)
+    result
+}
+
+# Private function
+_get_obj_n = lambda obj: any, elements: [str], n: int -> any {
+    assert n >= 0
+    result = obj
+    if n < len(elements):
+        result = _get_obj_n(get_obj_by_key(obj, elements[n]), elements, n + 1)
+    result
+}
+
+_build_patch_obj_n = lambda obj: {str:}, value: any, elements: [str], n: int -> {str:} {
+    assert n >= 0
+    result = Undefined
+    if n < len(elements):
+        current_path = "/".join(elements[:n+1])
+        current_obj = get_obj(obj, current_path)
+        assert current_obj not in NULL_CONSTANTS, "list value not found for path: ${current_path}"
+        if n + 1 < len(elements):
+            next_key = _get_list_index_from_key(elements[n + 1])
+            next_val = _build_patch_obj_n(obj, value, elements, n + 2)
+            # List key
+            if next_key not in NULL_CONSTANTS:
+                idx = next_key
+                assert 0 <= idx < len(current_obj), "value not found for path: {}".format(current_path + "/" + elements[n + 1])
+                result = {
+                    "${elements[n]}": [None] * idx + [next_val] + [None] * (len(current_obj) - 1 - idx)
+                }
+            # Config key
+            else:
+                result = {
+                    "${elements[n]}": next_val
+                }
+        # No Next value
+        else:
+            result = {
+                "${elements[n]}" = value
+            }
+    result
+}
+
+build_patch = lambda obj: any, path: str, value: any -> any {
+    _build_patch_obj_n(obj, value, path.lstrip('/').split('/'), 0)
+}
+
+set_obj = lambda obj: any, path: str, value: any -> any {
+    obj | _build_patch_obj_n(obj, value, path.lstrip('/').split('/'), 0)
+}
+
+apply_patch = lambda obj: any, patch: Patch {
+    dst = obj
+    if patch.op == "add":
+        assert False
+    elif patch.op == "remove":
+        assert False
+    elif patch.op == "replace":
+        dst = build_patch(obj, patch.path, patch.value)
+    elif patch.op == "move":
+        assert False
+    elif patch.op == "test":
+        assert False
+    elif patch.op == "copy":
+        assert False
+    dst
+}
+
+apply_patchs = lambda obj: any, patch: JsonPatch -> any {
+    """Apply list of patches to specified json document."""
+    assert False, "TODO: PRs welcome"
+    {}
+}
+
+make_patch = lambda src: any, dst: any -> JsonPatch {
+    """Generates patch by comparing two document objects."""
+    assert False, "TODO: PRs welcome"
+    []
+}