update readme

README.md

@@ -1,16 +1,23 @@
 # pluie-yaml
 
-vala shared library managing yaml files and yaml nodes in vala language.
+**pluie-yaml** is a vala shared library managing yaml files (v 1.2) and yaml nodes in vala language.  
+As json is now a valid subset of yaml, you can use this lib to load json files too.  
 
+The purpose of this project is to make vala able to load and deal with yaml configuration files.  
+**pluie-yaml** use the ![libyaml c library](https://github.com/yaml/libyaml) (License MIT, many thanks to Kirill Simonov) to parse and retriew related yaml events.
+
+## License
+
+GNU GPL v3
 
 ## Prerequisites
 
-valac meson ninja glib gio gee gobject pluie-echo
+`valac meson ninja glib gee gobject pluie-echo`
 
 
 ## Install
 
-git clone the project then cd to project and do :
+git clone the project then cd to project directory and do :
 
 ```
 meson --prefix=/usr ./ build
@@ -21,9 +28,12 @@ sudo ninja install -C build
 
 ```
 valac --pkg gee-0.8 --pkg pluie-echo-0.2 --pkg pluie-yaml-0.3 main.vala
-
 ```
 
+see https://git.pluie.org/pluie/libpluie-echo in order to install pluie-echo-0.2 pkg
+
+you can use `./build.sh` to rebuild/install the **pluie-yaml** lib and compile samples files
+
 ## Api / Documentation
 
 https://pluie.org/pluie-yaml-0.3/index.htm  
@@ -31,7 +41,7 @@ https://pluie.org/pluie-yaml-0.3/index.htm
 
 ## Docker
 
-a demo image will be available on docker hub. you can run a container with :
+a demo image will be available soon on docker hub. you will be able to run a container with :
 
 ```
 docker run --rm -it pluie/libyaml
@@ -39,14 +49,58 @@ docker run --rm -it pluie/libyaml
 
 ## Usage
 
+### loader 
+
 ```
-    var loader = new Yaml.Loader (path);
+    var path   = "./config/main.yml";
+    // uncomment to enable debug
+    // Pluie.Yaml.Scanner.DEBUG = true;
+    var loader = new Yaml.Loader (path /* , displayFile, displayNode */);
     if ((done = loader.done)) {
         Yaml.NodeRoot root = loader.get_nodes ();
         root.display_childs ();
     }
 ```
 
+### finder
+
+**lib-yaml** provide a `Yaml.Finder` to easily retriew a particular yaml node.  
+Search path definition has two mode.  
+The default mode is `Yaml.FIND_MODE.SQUARE_BRACKETS`  
+- node's key name must be enclosed in square brackets  
+- sequence entry must be enclosed in curly brace  
+
+ex : `[grandfather][father][son]{2}[age]`
+
+The Other mode is Yaml.FIND_MODE.DOT  
+- child mapping node are separated by dot
+- sequence entry must be enclosed in curly brace
+
+ex : `grandfather.father.son{2}.age`
+
+with singlepair node, you can retriew corresponding scalar node with {0}
+
+```
+/*
+# ex yaml file :
+product:
+    - sku         : BL394D
+      quantity    : 4
+      description : Basketball
+*/
+    ...
+    Yaml.NodeRoot root = loader.get_nodes ();
+    Yaml.Node?    node = null;
+    if ((node = finder.find("product{0}.description{0}")) != null) {
+        var val = node.data;
+    }
+```
+
 ### more samples
 
 see samples files in ./samples directory
+
+### todo
+
+* dumper
+* fix nodes traversing