Improved error message when accessing @private from other modules. Added convenience functions to Maybe.

lib/std/collections/maybe.c3

@@ -1,16 +1,43 @@
 module std::collections::maybe(<Type>);
+import std::io;
 
-struct Maybe
+struct Maybe (Printable)
 {
 	Type value;
 	bool has_value;
 }
 
+fn usz! Maybe.to_format(&self, Formatter* f) @dynamic
+{
+	if (self.has_value) return f.printf("[%s]", self.value);
+	return f.printf("[EMPTY]");
+}
+
+fn void Maybe.set(&self, Type val)
+{
+	*self = { .value = val, .has_value = true };
+}
+
+fn void Maybe.reset(&self)
+{
+	*self = {};
+}
+
 fn Maybe value(Type val)
 {
 	return { .value = val, .has_value = true };
 }
 
+fn Maybe Maybe.with_value(Type val) @operator(construct)
+{
+	return { .value = val, .has_value = true };
+}
+
+fn Maybe Maybe.empty() @operator(construct)
+{
+	return { };
+}
+
 const Maybe EMPTY = { };
 
 macro Type! Maybe.get(self)

releasenotes.md

@@ -17,6 +17,7 @@
 - Allow using 'var' to declare lambdas in functions.
 - Add 'validation' setting and make dead code a warning.
 - Allow compile time `$foreach` iteration over constant Strings and bytes.
+- Improved error message when accessing `@private` from other modules #1769.
 
 ### Fixes
 - Fix case trying to initialize a `char[*]*` from a String.
@@ -62,6 +63,7 @@
 - Add `@enum_from_value`.
 - Updated hash function.
 - Added URL parser.
+- Added convenience functions to `Maybe`.
 
 ## 0.6.5 Change list
 

src/compiler/sema_name_resolution.c

@@ -136,7 +136,7 @@ static inline Decl *sema_find_decl_in_module(Module *module, Path *path, const c
 	return module_find_symbol(module, symbol);
 }
 
-static bool sema_find_decl_in_private_imports(SemaContext *context, NameResolve *name_resolve, bool want_generic)
+static bool sema_find_decl_in_imports(SemaContext *context, NameResolve *name_resolve, bool want_generic)
 {
 	Decl *decl = NULL;
 	// 1. Loop over imports.
@@ -145,7 +145,8 @@ static bool sema_find_decl_in_private_imports(SemaContext *context, NameResolve
 	FOREACH(Decl *, import, context->unit->imports)
 	{
 		if (import->import.module->is_generic != want_generic) continue;
-		if (!import->import.import_private_as_public) continue;
+		bool is_private_import = import->import.import_private_as_public;
+		if (!path && (decl || !is_private_import)) continue;
 		// Is the decl in the import.
 		Decl *found = sema_find_decl_in_module(import->import.module, path, symbol, &name_resolve->path_found);
 
@@ -154,6 +155,16 @@ static bool sema_find_decl_in_private_imports(SemaContext *context, NameResolve
 
 		ASSERT0(found->visibility != VISIBLE_LOCAL);
 
+		if (found->visibility != VISIBLE_PUBLIC)
+		{
+			if (decl) continue;
+			if (!is_private_import)
+			{
+				name_resolve->private_decl = found;
+				continue;
+			}
+		}
+
 		// Did we already have a match?
 		if (decl)
 		{
@@ -418,7 +429,7 @@ static bool sema_resolve_path_symbol(SemaContext *context, NameResolve *name_res
 	}
 
 	// 3. Loop over imports.
-	if (!sema_find_decl_in_private_imports(context, name_resolve, false)) return false;
+	if (!sema_find_decl_in_imports(context, name_resolve, false)) return false;
 
 	// 4. Go to global search
 	if (name_resolve->found) return true;
@@ -493,7 +504,7 @@ static bool sema_resolve_no_path_symbol(SemaContext *context, NameResolve *name_
 		return true;
 	}
 
-	if (!sema_find_decl_in_private_imports(context, name_resolve, false)) return false;
+	if (!sema_find_decl_in_imports(context, name_resolve, false)) return false;
 	if (name_resolve->found) return true;
 
 	return sema_find_decl_in_global(context, &compiler.context.symbols, NULL, name_resolve, false);
@@ -582,12 +593,12 @@ static void sema_report_error_on_decl(SemaContext *context, NameResolve *name_re
 		const char *private_name = decl_to_name(name_resolve->private_decl);
 		if (path_name)
 		{
-			sema_error_at(context, span, "The %s '%s::%s' is not visible from this module.",
+			sema_error_at(context, span, "The %s '%s::%s' is '@private' and not visible from other modules.",
 			              private_name, path_name,
 			              symbol);
 		} else
 		{
-			sema_error_at(context, span, "The %s '%s' is not visible from this module.",
+			sema_error_at(context, span, "The %s '%s' is '@private' and not visible from other modules.",
 			              private_name, symbol);
 		}
 		return;
@@ -982,7 +993,7 @@ bool unit_resolve_parameterized_symbol(SemaContext *context, NameResolve *name_r
 	name_resolve->private_decl = NULL;
 	name_resolve->path_found = NULL;
 
-	if (!sema_find_decl_in_private_imports(context, name_resolve, true)) return false;
+	if (!sema_find_decl_in_imports(context, name_resolve, true)) return false;
 	if (!name_resolve->found)
 	{
 		if (!sema_find_decl_in_global(context, &compiler.context.generic_symbols,

test/test_suite/visibility/not_visible.c3t

@@ -4,7 +4,7 @@ import bar;
 
 fn void runBar()
 {
-    bar::notVisible(); // #error: 'bar::notVisible' could not be found
+    bar::notVisible(); // #error: 'bar::notVisible' is '@private'
 }
 
 // #file: file2.c3

test/test_suite/visibility/private_import.c3

@@ -9,7 +9,7 @@ import foo;
 
 fn void test()
 {
-    foo::hidden(); // #error: 'foo::hidden' could not be found,
+    foo::hidden(); // #error: 'foo::hidden' is '@private'
 }
 
 module baz;

test/test_suite/visibility/private_import2.c3

@@ -22,6 +22,6 @@ import test;
 
 fn void abc()
 {
-	test::bar(); // #error: could not be found
+	test::bar(); // #error: is '@private'
 	test::bar2(); // #error: could not be found
 }