fix: add esquery style doc

Author: HerringtonDarkholme

src/utils.rs

@@ -45,6 +45,15 @@ fn get_message(rule: &RuleConfig<WasmLang>, node: &NodeMatch) -> String {
 }
 
 impl WasmMatch {
+  pub fn from_pattern(nm: NodeMatch) -> Self {
+    let node = nm.get_node().clone();
+    let kind = node.kind().to_string();
+    let node = WasmNode::from(node);
+    let env = nm.get_env().clone();
+    let env = env_to_map(env);
+    let message = String::new();
+    Self { node, env, message, kind }
+  }
   pub fn from_match(nm: NodeMatch, rule: &RuleConfig<WasmLang>) -> Self {
     let node = nm.get_node().clone();
     let kind = node.kind().to_string();

website/guide/rule-config/atomic-rule.md

@@ -125,6 +125,26 @@ To change the parsing behavior of `pattern`, you should use pattern object with
 See [this FAQ](/advanced/faq.html#kind-and-pattern-rules-are-not-working-together-why).
 :::
 
+### ESQuery style `kind` <Badge type="warning" text="Experimental" />
+
+From ast-grep v0.39.1, you can also use ESQuery style selector in `kind` to match AST nodes. This is an experimental feature and may change in the future.
+
+```yaml
+rule:
+  kind: call_expression > identifier
+```
+This will match the `identifier` node that is a child of `call_expression` node. Internally, it will be converted to a [relational rule](/guide/rule-config/relational-rule.html) `has`.
+
+Currently, the ESQuery style `kind` only supports the following selectors:
+* node kind: `identifier`
+* `>`: direct child selectors
+* `+`: next sibling selector
+* `~`: following sibling selector
+* ` `: descendant selector
+
+If you want more selectors, please respond to [this issue on GitHub](https://github.com/ast-grep/ast-grep/issues/2127).
+
+
 ## `regex`
 
 The `regex` atomic rule will match the AST node by its text against a Rust regular expression.

website/reference/rule.md

@@ -21,7 +21,7 @@ A rule is called **positive** if it only matches nodes with specific kinds. For
 
 A `String` pattern will match one single AST node according to [pattern syntax](/guide/pattern-syntax).
 
-Example:
+**Example:**
 
 ```yml
 pattern: console.log($ARG)
@@ -61,12 +61,19 @@ pattern:
 
 The kind name of the node to match. You can look up code's kind names in [playground](/playground).
 
-Example:
+**Example:**
 
 ```yml
 kind: call_expression
 ```
 
+ast-grep 0.39+ also supports limited ESQuery syntax for `kind`:
+
+**Example:**
+```yml
+kind: call_expression > identifier
+```
+
 ### `regex`
 * type: `String`