refactor: big changes

Cargo.toml

@@ -1,5 +1,5 @@
 [workspace]
-members = ['packages/uischema', 'packages/optics']
+members = ['packages/uischema', 'packages/jmespath_optic']
 resolver = '2'
 
 [profile.release]

packages/optics/Cargo.toml → packages/jmespath_optic/Cargo.toml

@@ -1,8 +1,10 @@
 [package]
-name = "optics"
+name = "jmespath_optic"
 version = "0.1.0"
 edition = "2021"
 
 # See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
 
 [dependencies]
+jmespath = "0.3.0"
+serde_json = "1.0.106"

packages/jmespath_optic/src/lib.rs

@@ -0,0 +1,33 @@
+use jmespath::ast::Ast;
+use serde_json::Value;
+
+pub trait JmesTraversal {
+    fn modify_json_value(&self, source: Value, target: Value) -> Value;
+}
+
+impl JmesTraversal for &Ast {
+    fn modify_json_value(&self, source: Value, target: Value) -> Value {
+        match self {
+            Ast::Identity { .. } => target,
+            Ast::And { lhs, rhs, .. } => target,
+            _ => todo!(),
+        }
+    }
+}
+
+#[cfg(test)]
+mod test {
+    use super::*;
+
+    #[test]
+    fn identity() {
+        let expression = jmespath::compile("@").unwrap();
+        let ast = expression.as_ast();
+        assert_eq!(ast, &Ast::Identity { offset: 0 });
+
+        let source: Value = serde_json::from_str(r#"{ "hello": "world" }"#).unwrap();
+        let target = source.clone();
+        let result: Value = ast.modify_json_value(source, target.clone());
+        assert_eq!(result, target);
+    }
+}