feat(name resolution): somewhat better handling of closures and captures

include/Ark/VM/Value/Closure.hpp

@@ -61,6 +61,15 @@ namespace Ark::internal
          */
         [[nodiscard]] PageAddr_t pageAddr() const { return m_page_addr; }
 
+        /**
+         * @brief Used when generating error messages in the VM, to see if a symbol might have been wrongly fully qualified
+         *
+         * @param end
+         * @param vm
+         * @return true if the closure has a field which is the end of 'end'
+         */
+        [[nodiscard]] bool hasFieldEndingWith(const std::string& end, VM& vm) const;
+
         /**
          * @brief Print the closure to a string
          *

src/arkreactor/VM/VM.cpp

@@ -619,7 +619,22 @@ namespace Ark
                                 push(field, context);
                         }
                         else
-                            throwVMError(ErrorKind::Scope, fmt::format("`{}' isn't in the closure environment: {}", m_state.m_symbols[arg], var->refClosure().toString(*this)));
+                        {
+                            if (!var->refClosure().hasFieldEndingWith(m_state.m_symbols[arg], *this))
+                                throwVMError(
+                                    ErrorKind::Scope,
+                                    fmt::format(
+                                        "`{0}' isn't in the closure environment: {1}",
+                                        m_state.m_symbols[arg],
+                                        var->refClosure().toString(*this)));
+                            throwVMError(
+                                ErrorKind::Scope,
+                                fmt::format(
+                                    "`{0}' isn't in the closure environment: {1}. A variable in the package might have the same name as '{0}', "
+                                    "and name resolution tried to fully qualify it. Rename either the variable or the capture to solve this",
+                                    m_state.m_symbols[arg],
+                                    var->refClosure().toString(*this)));
+                        }
                         DISPATCH();
                     }
 

src/arkreactor/VM/Value/Closure.cpp

@@ -4,6 +4,8 @@
 #include <Ark/VM/Value.hpp>
 #include <Ark/VM/VM.hpp>
 
+#include <ranges>
+
 namespace Ark::internal
 {
     Closure::Closure(const Scope& scope, const PageAddr_t pa) noexcept :
@@ -16,6 +18,16 @@ namespace Ark::internal
         m_page_addr(pa)
     {}
 
+    bool Closure::hasFieldEndingWith(const std::string& end, VM& vm) const
+    {
+        for (const auto id : std::ranges::views::keys(m_scope->m_data))
+        {
+            if (end.ends_with(":" + vm.m_state.m_symbols[id]))
+                return true;
+        }
+        return false;
+    }
+
     std::string Closure::toString(VM& vm) const noexcept
     {
         std::string out = "(";

tests/unittests/resources/DiagnosticsSuite/runtime/closure_field_wrong_fqn.ark

@@ -0,0 +1 @@
+(import closure_field_wrong_fqn.b)

tests/unittests/resources/DiagnosticsSuite/runtime/closure_field_wrong_fqn.expected

@@ -0,0 +1 @@
+ScopeError: `b:b' isn't in the closure environment: (.a=hello .b=1). A variable in the package might have the same name as 'b:b', and name resolution tried to fully qualify it. Rename either the variable or the capture to solve this

tests/unittests/resources/DiagnosticsSuite/runtime/closure_field_wrong_fqn/b.ark

@@ -0,0 +1,10 @@
+(let tests 0)
+(let closure (fun (&tests) ()))
+
+(let a 1)
+(let b 2)
+
+(let make (fun (a b)
+    (fun (&a &b) ())))
+(let foo (make "hello" 1))
+(let c [foo.a foo.b])

tests/unittests/resources/LangSuite/list-tests.ark

@@ -4,14 +4,14 @@
 (let b [4 5 6])
 
 (test:suite list {
-    (let make (fun (a b)
-        (fun (&a &b) ())))
+    (let make (fun (c d)
+        (fun (&c &d) ())))
     (let foo (make "hello" 1))
 
     # if this is failing, this is most likely to be a compiler problem
-    (test:eq ["hello" 1] [foo.a foo.b])
-    (test:eq 2 (len [foo.a foo.b]))
-    (test:eq ["hello"] (append [] foo.a))
+    (test:eq ["hello" 1] [foo.c foo.d])
+    (test:eq 2 (len [foo.c foo.d]))
+    (test:eq ["hello"] (append [] foo.c))
 
     (test:case "append and return a new list" {
         (test:eq (append a 4) [1 2 3 4])

tests/unittests/resources/LangSuite/vm-tests.ark

@@ -126,11 +126,11 @@
         (test:eq (type nil) "Nil")
         (test:eq (type true) "Bool")
         (test:eq (type false) "Bool")
-        (test:expect (hasField closure "tests"))
+        (test:expect (hasField closure "vm-tests:tests"))
         (test:expect (not (hasField closure "12"))) })
 
     (test:case "closures" {
-        (test:eq (toString closure) "(.tests=0)")
+        (test:eq (toString closure) "(.vm-tests:tests=0)")
         (test:eq closure_1 closure_1_bis)
         (test:eq closure_1 closure_2)
         (test:neq closure_1 closure_4)