Initial project import

tools/v/vlib/x/json2/custom.v

@@ -0,0 +1,64 @@
+module json2
+
+// implements encoding json, this is not validated so implementations must be correct
+pub interface JsonEncoder {
+	// to_json returns a string containing an objects json representation
+	to_json() string
+}
+
+// Encodable is an interface, that allows custom implementations for encoding structs to their string based JSON representations.
+
+@[deprecated: 'use `to_json` to implement `JsonEncoder` instead']
+@[deprecated_after: '2025-10-30']
+pub interface Encodable {
+	json_str() string
+}
+
+// implements decoding json strings, e.g. "hello, \u2164!"
+pub interface StringDecoder {
+mut:
+	// called with raw string (minus apostrophes) e.g. 'hello, \u2164!'
+	from_json_string(raw_string string) !
+}
+
+// implements decoding json numbers, e.g. -1.234e23
+pub interface NumberDecoder {
+mut:
+	// called with raw string of number e.g. '-1.234e23'
+	from_json_number(raw_number string) !
+}
+
+// implements decoding json true/false
+pub interface BooleanDecoder {
+mut:
+	// called with converted bool
+	// already checked so no error needed
+	from_json_boolean(boolean_value bool)
+}
+
+// implements decoding json null
+pub interface NullDecoder {
+mut:
+	// only has one value
+	// already checked so no error needed
+	from_json_null()
+}
+
+// Implement once generic interfaces are more stable
+
+// // implements decoding json arrays, e.g. ["hi", "bye", 0.9, true]
+// // elements are already decoded
+// pub interface ArrayDecoder[T] {
+// mut:
+// 	// called for every element in array e.g. 'hi', 'bye', '0.9', 'true'
+// 	from_json_value(raw_value T)!
+// }
+
+// // implements decoding json object, e.g. {"name": "foo", "name": "bar", "age": 99}
+// // this allows for duplicate/ordered keys to be decoded
+// // elements are already decoded
+// pub interface ObjectDecoder[T] {
+// mut:
+// 	// called for every key-value pair in object (minus apostrophes for keys) e.g. ('name': 'foo'), ('name': 'bar'), ('age': '99')
+// 	from_json_pair(raw_key string, raw_value T)!
+// }