✨ feat(mq-lang, mq-markdown): Add table header selector support

This commit enhances table handling capabilities in mq by adding support for table header selectors:

- Added `is_table_header()` helper function to builtin.mq for checking table header nodes
- Extended `.table` selector in builtin.rs to match table header nodes when using `.table` without row/column parameters
- Added `is_table_header()` method to the Node enum in mq-markdown for type checking
- Included comprehensive test cases for table header selector matching scenarios
- Added documentation for `.table` and `.[]` selectors in BUILTIN_SELECTOR_DOC

This change allows users to select and manipulate table headers using the same `.table` selector syntax, improving consistency in table processing workflows.

Author: harehare

crates/mq-lang/builtin.mq

@@ -162,6 +162,9 @@ def is_h_level(md, level):
     error("Invalid heading level: " + to_string(level))
 end
 
+# Checks if markdown is table header
+def is_table_header(md): to_md_name(md) == "table_header";
+
 # Checks if markdown is emphasis
 def is_em(md): to_md_name(md) == "emphasis";
 

crates/mq-lang/src/eval/builtin.rs

@@ -2643,6 +2643,14 @@ pub static BUILTIN_SELECTOR_DOC: LazyLock<FxHashMap<SmolStr, BuiltinSelectorDoc>
         },
     );
 
+    map.insert(
+        SmolStr::new(".table"),
+        BuiltinSelectorDoc {
+            description: "Selects a table cell node with the specified row and column.",
+            params: &["row", "column"],
+        },
+    );
+
     map.insert(
         SmolStr::new(".html"),
         BuiltinSelectorDoc {
@@ -2683,6 +2691,14 @@ pub static BUILTIN_SELECTOR_DOC: LazyLock<FxHashMap<SmolStr, BuiltinSelectorDoc>
         },
     );
 
+    map.insert(
+        SmolStr::new(".[]"),
+        BuiltinSelectorDoc {
+            description: "Selects a list node with the specified index and checked state.",
+            params: &["indent", "checked"],
+        },
+    );
+
     map.insert(
         SmolStr::new(".mdx_js_esm"),
         BuiltinSelectorDoc {
@@ -3712,7 +3728,7 @@ pub fn eval_selector(node: &mq_markdown::Node, selector: &Selector) -> bool {
             (None, Some(column1), mq_markdown::Node::TableCell(mq_markdown::TableCell { column: column2, .. })) => {
                 *column1 == column2
             }
-            (None, None, mq_markdown::Node::TableCell(_)) => true,
+            (None, None, mq_markdown::Node::TableCell(_)) | (None, None, mq_markdown::Node::TableHeader(_)) => true,
             _ => false,
         },
         Selector::Html => node.is_html(),
@@ -4224,6 +4240,26 @@ mod tests {
         Selector::Table(Some(1), None),
         true
     )]
+    #[case::table_header_with_no_row_col(
+        Node::TableHeader(mq_markdown::TableHeader { align: vec![], position: None }),
+        Selector::Table(None, None),
+        true
+    )]
+    #[case::table_header_with_only_row(
+        Node::TableHeader(mq_markdown::TableHeader { align: vec![], position: None }),
+        Selector::Table(Some(2), None),
+        false
+    )]
+    #[case::table_header_with_only_col(
+        Node::TableHeader(mq_markdown::TableHeader { align: vec![], position: None }),
+        Selector::Table(None, Some(3)),
+        false
+    )]
+    #[case::table_header_with_row_col(
+        Node::TableHeader(mq_markdown::TableHeader { align: vec![], position: None }),
+        Selector::Table(Some(1), Some(1)),
+        false
+    )]
     #[case::list_with_matching_index_checked(
         Node::List(mq_markdown::List { values: vec!["test".to_string().into()], ordered: false, index: 1, level: 1, checked: Some(true), position: None }),
         Selector::List(Some(1), Some(true)),

crates/mq-markdown/src/node.rs

@@ -1382,6 +1382,10 @@ impl Node {
         matches!(self, Self::TableCell(_))
     }
 
+    pub fn is_table_header(&self) -> bool {
+        matches!(self, Self::TableHeader(_))
+    }
+
     pub fn is_table_row(&self) -> bool {
         matches!(self, Self::TableRow(_))
     }