Python bindings (#115)

Signed-off-by: Anand Krishnamoorthi <anakrish@microsoft.com>

bindings/wasm/Cargo.toml

@@ -1,5 +1,5 @@
 [package]
-name = "regorus-wasm"
+name = "regorusjs"
 version = "0.1.0"
 edition = "2021"
 repository = "https://github.com/microsoft/regorus/bindings/wasm"

bindings/wasm/README.md

@@ -1,4 +1,4 @@
-# regorus-wasm
+# regorusjs
 
 **Regorus** is
 
@@ -8,21 +8,70 @@
 
 See [Repository](https://github.com/microsoft/regorus).
 
-`regorus-wasm` is Regorus compiled into WASM.
+`regorusjs` is Regorus compiled into WASM.
 
 ## Usage
 
-In nodejs,
+```javascript
 
-``javascript
-
-var regorus = require('regorus-wasm')
+var regorus = require('regorusjs')
 
 // Create an engine.
 var engine = new regorus.Engine();
 
 // Add Rego policy.
-engine.add_policy()
+engine.add_policy(
+    // Associate this file name with policy
+    'hello.rego',
+    
+    // Rego policy
+`
+  package test
+  
+  # Join messages
+  message = concat(", ", [input.message, data.message])
+`)
 
+// Set policy data
+engine.add_data_json(`
+ {
+    "message" : "World!"
+ }
+`)
 
+// Set policy input
+engine.set_input_json(`
+ {
+	"message" : "Hello"
+ }
+`)
+
+// Eval query
+results = engine.eval_query('data.test.message')
+
+// Display
+console.log(results)
+// {
+//   "result": [
+//     {
+//       "expressions": [
+//         {
+//           "value": "Hello, World!",
+//           "text": "data.test.message",
+//           "location": {
+//             "row": 1,
+//             "col": 1
+//           }
+//         }
+//       ]
+//     }
+//   ]
+// }
+
+// Convert results to object
+results = JSON.parse(results)
+
+// Process result
+console.log(results.result[0].expressions[0].value)
+// Hello, World!
 ```

bindings/wasm/src/lib.rs

@@ -63,6 +63,12 @@ impl Engine {
         self.engine.add_data(data).map_err(error_to_jsvalue)
     }
 
+    /// Clear policy data.
+    pub fn clear_data(&mut self) -> Result<(), JsValue> {
+        self.engine.clear_data();
+        Ok(())
+    }
+
     /// Set input.
     ///
     /// See https://docs.rs/regorus/0.1.0-alpha.2/regorus/struct.Engine.html#method.set_input