added a small readme

Author: meir

README.md

@@ -1,2 +1,49 @@
 # JsonPathCalculator
-Json path calculator library for rust
+Json path calculator library for rust. The idea behind this library is that it can operate on any json representation as long as it implements the [`SelectValue`](src/select_value.rs) triat. The library has an implementation for [serde_json value](https://docs.serde.rs/serde_json/value/enum.Value.html) and [ivalue](https://docs.rs/tch/0.1.1/tch/enum.IValue.html).
+
+### Getting Started
+Add the following to your cargo.toml
+
+```rust
+[dependencies]
+jsonpath_calculator = { git = "https://github.com/RedisJSON/JsonPathCalculator.git", branch = "master" }
+```
+
+Usage example:
+
+```rust
+extern crate jsonpath_calculator
+#[macro_use] extern crate serde_json;
+
+fn main() {
+    let mut query = jsonpath_calculator::compile("$..friends[0]");
+    let calculator = jsonpath_calculator::create(&query)
+
+    let json_obj = json!({
+        "school": {
+            "friends": [
+                {"name": "친구1", "age": 20},
+                {"name": "친구2", "age": 20}
+            ]
+        },
+        "friends": [
+            {"name": "친구3", "age": 30},
+            {"name": "친구4"}
+        ]
+    });
+
+    let json = calculator.calc(&json_obj);
+
+    assert_eq!(json, vec![
+        &json!({"name": "친구3", "age": 30}),
+        &json!({"name": "친구1", "age": 20})
+    ]);
+}
+```
+
+### Tests
+`jsonpath_calculator` pass **Almost** all the tests on https://github.com/freestrings/jsonpath, to run the tests:
+
+```
+cargo test
+```

src/lib.rs

@@ -22,6 +22,32 @@ use json_path::{
 
 /// Create a PathCalculator object. The path calculator can be re-used
 /// to calculate json paths on different jsons.
+/// /// ```rust
+/// extern crate jsonpath_calculator
+/// #[macro_use] extern crate serde_json;
+///
+/// let mut query = jsonpath_calculator::compile("$..friends[0]");
+/// let calculator = jsonpath_calculator::create(&query)
+///
+/// let json_obj = json!({
+///     "school": {
+///         "friends": [
+///             {"name": "친구1", "age": 20},
+///             {"name": "친구2", "age": 20}
+///         ]
+///     },
+///     "friends": [
+///         {"name": "친구3", "age": 30},
+///         {"name": "친구4"}
+/// ]});
+///
+/// let json = calculator.calc(&json_obj);
+///
+/// assert_eq!(json, vec![
+///     &json!({"name": "친구3", "age": 30}),
+///     &json!({"name": "친구1", "age": 20})
+/// ]);
+/// ```
 pub fn create<'i>(query: &'i Query<'i>) -> PathCalculator<'i, DummyTrackerGenerator> {
     PathCalculator::create(query)
 }