From 3d8492ca99d4dcb4d4fc085fce4e8b5468c3ee6a Mon Sep 17 00:00:00 2001
From: dak2 <dawt2h@gmail.com>
Date: Sat, 31 Jan 2026 16:28:12 +0900
Subject: [PATCH] Support Regexp

---
 rust/src/analyzer/literals.rs               | 15 +++++-
 rust/src/analyzer/tests/integration_test.rs | 54 +++++++++++++++++++++
 rust/src/types.rs                           |  6 +++
 3 files changed, 74 insertions(+), 1 deletion(-)

diff --git a/rust/src/analyzer/literals.rs b/rust/src/analyzer/literals.rs
index 2628fd4..98f3995 100644
--- a/rust/src/analyzer/literals.rs
+++ b/rust/src/analyzer/literals.rs
@@ -1,7 +1,7 @@
 //! Literal Handlers - Processing Ruby literal values
 //!
 //! This module is responsible for:
-//! - String, Integer, Float, Hash literals
+//! - String, Integer, Float, Hash, Regexp literals
 //! - nil, true, false, Symbol literals
 //! - Creating Source vertices with fixed types
 //!
@@ -57,6 +57,11 @@ pub fn install_literal(genv: &mut GlobalEnv, node: &Node) -> Option<VertexId> {
         return Some(genv.new_source(Type::symbol()));
     }
 
+    // /pattern/
+    if node.as_regular_expression_node().is_some() {
+        return Some(genv.new_source(Type::regexp()));
+    }
+
     None
 }
 
@@ -89,4 +94,12 @@ mod tests {
         let vtx = genv.new_source(Type::float());
         assert_eq!(genv.get_source(vtx).unwrap().ty.show(), "Float");
     }
+
+    #[test]
+    fn test_install_regexp_literal() {
+        let mut genv = GlobalEnv::new();
+
+        let vtx = genv.new_source(Type::regexp());
+        assert_eq!(genv.get_source(vtx).unwrap().ty.show(), "Regexp");
+    }
 }
diff --git a/rust/src/analyzer/tests/integration_test.rs b/rust/src/analyzer/tests/integration_test.rs
index c645123..3898940 100644
--- a/rust/src/analyzer/tests/integration_test.rs
+++ b/rust/src/analyzer/tests/integration_test.rs
@@ -34,6 +34,11 @@ fn analyze(source: &str) -> (GlobalEnv, LocalEnv) {
     genv.register_builtin_method(Type::array(), "map", Type::array());
     genv.register_builtin_method(Type::hash(), "each", Type::hash());
 
+    // Register Regexp methods
+    genv.register_builtin_method(Type::regexp(), "match", Type::instance("MatchData"));
+    genv.register_builtin_method(Type::regexp(), "match?", Type::instance("TrueClass"));
+    genv.register_builtin_method(Type::regexp(), "source", Type::string());
+
     let mut lenv = LocalEnv::new();
     let mut installer = AstInstaller::new(&mut genv, &mut lenv, source);
 
@@ -471,3 +476,52 @@ c = x.abs
     let c_vtx = lenv.get_var("c").unwrap();
     assert_eq!(genv.get_vertex(c_vtx).unwrap().show(), "Float");
 }
+
+// ============================================
+// Regexp Literal Tests
+// ============================================
+
+#[test]
+fn test_regexp_literal_basic() {
+    let source = r#"x = /hello/"#;
+
+    let (genv, lenv) = analyze(source);
+
+    let x_vtx = lenv.get_var("x").unwrap();
+    assert_eq!(genv.get_vertex(x_vtx).unwrap().show(), "Regexp");
+}
+
+#[test]
+fn test_regexp_literal_type_error() {
+    let source = r#"
+class Matcher
+  def find
+    x = /pattern/
+    y = x.upcase
+  end
+end
+"#;
+
+    let (genv, _lenv) = analyze(source);
+
+    // Type error should be detected: Regexp doesn't have upcase method
+    assert_eq!(genv.type_errors.len(), 1);
+    assert_eq!(genv.type_errors[0].method_name, "upcase");
+}
+
+#[test]
+fn test_regexp_specific_methods() {
+    let source = r#"
+x = /hello/
+a = x.source
+"#;
+
+    let (genv, lenv) = analyze(source);
+
+    // No type errors - source is a valid Regexp method
+    assert_eq!(genv.type_errors.len(), 0);
+
+    // source returns String
+    let a_vtx = lenv.get_var("a").unwrap();
+    assert_eq!(genv.get_vertex(a_vtx).unwrap().show(), "String");
+}
diff --git a/rust/src/types.rs b/rust/src/types.rs
index 0675e12..4580a1c 100644
--- a/rust/src/types.rs
+++ b/rust/src/types.rs
@@ -242,6 +242,12 @@ impl Type {
         }
     }
 
+    pub fn regexp() -> Self {
+        Type::Instance {
+            name: QualifiedName::simple("Regexp"),
+        }
+    }
+
     /// Create a generic Array type: Array[element_type]
     pub fn array_of(element_type: Type) -> Self {
         Type::Generic {