From 2dfe73de6b315e8634ac2705b74c9d3260f6246a Mon Sep 17 00:00:00 2001
From: Ava Hahn <ava@sunnypup.io>
Date: Fri, 17 Mar 2023 12:01:43 -0700
Subject: [PATCH] variables defined using def in a let statement now escape
 local scope test added as well.

---
 src/stl/control.rs        | 13 +++++++++++++
 src/sym.rs                |  4 ++++
 tests/test_lib_control.rs | 20 ++++++++++++++++++++
 3 files changed, 37 insertions(+)

diff --git a/src/stl/control.rs b/src/stl/control.rs
index 0b94f30..6a6509c 100644
--- a/src/stl/control.rs
+++ b/src/stl/control.rs
@@ -111,6 +111,7 @@ Since the call to some-func is the final form, its value is returned.";
 
 pub fn let_callback(ast: &Seg, syms: &mut SymTable) -> Result<Ctr, String> {
     let mut localsyms = syms.clone();
+    let mut locals = vec![];
     let locals_form: &Seg;
     let eval_forms: &Seg;
     if let Ctr::Seg(ref locals_form_list) = *ast.car {
@@ -156,6 +157,7 @@ pub fn let_callback(ast: &Seg, syms: &mut SymTable) -> Result<Ctr, String> {
                             &Seg::from_mono(Box::new(*var_val_res.unwrap().clone())),
                             None),
                     );
+                    locals.push(name.clone());
                 }
             } else if let Ctr::None = *var_form.car {
                 // nothing to declare
@@ -201,6 +203,17 @@ pub fn let_callback(ast: &Seg, syms: &mut SymTable) -> Result<Ctr, String> {
         return Err("evaluation failure".to_string());
     }
 
+    // we need to get any var declared from within the let eval forms
+    // those need to exist in the outside context
+    for i in localsyms.iter() {
+        if !locals.contains(i.0) && !syms.contains_key(i.0) {
+            syms.insert(
+                i.0.clone(),
+                i.1.clone(),
+            );
+        }
+    }
+
     Ok((*result).clone())
 }
 
diff --git a/src/sym.rs b/src/sym.rs
index e8bf507..2a17285 100644
--- a/src/sym.rs
+++ b/src/sym.rs
@@ -79,6 +79,10 @@ impl SymTable {
         self.0.get(arg)
     }
 
+    pub fn contains_key(&self, arg: &String) -> bool {
+        self.0.contains_key(arg)
+    }
+
     pub fn insert(&mut self, k: String, v: Symbol) -> Option<Symbol> {
         self.0.insert(k, v)
     }
diff --git a/tests/test_lib_control.rs b/tests/test_lib_control.rs
index 13e2f9b..56defb5 100644
--- a/tests/test_lib_control.rs
+++ b/tests/test_lib_control.rs
@@ -65,6 +65,26 @@ mod control_lib_tests {
         );
     }
 
+    #[test]
+    fn test_let_def_escapes_locals() {
+        let document1 = "(let (
+                           (temp 'hello')
+                           (temp (concat temp ' ' 'world')))
+                          (def global '' temp))";
+        let document2 = "global";
+        let result = "('hello world')";
+        let mut syms = SymTable::new();
+        static_stdlib(&mut syms).unwrap();
+        dynamic_stdlib(&mut syms).unwrap();
+        eval(&lex(&document1.to_string()).unwrap(), &mut syms).unwrap();
+        assert_eq!(
+            *eval(&lex(&document2.to_string()).unwrap(), &mut syms)
+                .unwrap()
+                .to_string(),
+            result.to_string(),
+        );
+    }
+
     #[test]
     fn test_let_multibody_evals() {
         let document = "(let ((temp '1')) temp (cons () temp '2'))";