Initial attempt of implementation

Cargo.toml

@@ -9,7 +9,12 @@ repository = "https://github.com/jihchi/kq.git"
 license-file = "LICENSE"
 keywords = ["kdl", "query", "transform", "config", "document"]
 
+[dev-dependencies]
+assert_cmd = "2.0.2"
+predicates = "2.0.3"
+indoc = "1.0.3"
+
 [dependencies]
-kdl = "1.1.0"
+kdl = "3.0.0"
 nom = "7.0.0"
 getopts = "0.2"

README.md

@@ -4,9 +4,23 @@
 [![Crates.io - download](https://img.shields.io/crates/d/kq)](https://crates.io/crates/kq)
 [![docs.rs](https://img.shields.io/docsrs/kq)](https://docs.rs/kq)
 
->  🚧 work in progress
+A jq-like cli tool that can [query](https://github.com/kdl-org/kdl/blob/1.0.0/QUERY-SPEC.md) and transform [KDL](https://kdl.dev/) document right in the command line.
 
-A jq-like cli tool that can [query](https://github.com/kdl-org/kdl/blob/main/QUERY-SPEC.md) and transform [KDL](https://kdl.dev/) document right in the command line.
+> `||` and [Map Operator](https://github.com/kdl-org/kdl/blob/1.0.0/QUERY-SPEC.md#map-operator) are not supported yet.
+
+## Installation
+
+### Cargo
+
+```sh
+cargo install kq
+```
+
+## Usage
+
+> Modified from https://github.com/kdl-org/kdl/blob/1.0.0/QUERY-SPEC.md#examples
+
+Given following content:
 
 ```console
 $ cat example.kdl
@@ -20,34 +34,32 @@ package {
         miette "2.0.0" dev=true
     }
 }
+```
 
+```console
 $ cat example.kdl | kq "package name"
 name "foo"
+```
 
+```console
 $ cat example.kdl | kq "dependencies"
 dependencies platform="windows" {
     winapi "1.0.0" path="./crates/my-winapi-fork"
 }
 dependencies {
     miette "2.0.0" dev=true
 }
+```
 
+```console
 $ cat example.kdl | kq "dependencies[platform]"
 dependencies platform="windows" {
     winapi "1.0.0" path="./crates/my-winapi-fork"
 }
+```
 
+```console
 $ cat example.kdl | kq "dependencies > []"
 winapi "1.0.0" path="./crates/my-winapi-fork"
 miette "2.0.0" dev=true
-
-```
-
-## Installation
-
-### Cargo
-
-```sh
-cargo install kq
 ```
-

src/cli.rs

@@ -26,9 +26,7 @@ impl Args {
             program,
         })
     }
-}
 
-impl Args {
     pub fn help(&self) -> bool {
         self.matches.opt_present("h")
     }
@@ -37,9 +35,8 @@ impl Args {
         self.matches.opt_present("v")
     }
 
-    pub fn get_free(&self) -> Option<String> {
-        let some = !self.matches.free.is_empty();
-        some.then(|| self.matches.free[0].clone())
+    pub fn get_query(&self) -> Option<&String> {
+        self.matches.free.get(0)
     }
 
     pub fn print_help(&self) {