support `.Type` syntax for module type lookup

dsymbol/src/dsymbol/builtin/names.d

@@ -27,6 +27,15 @@ package istring[24] builtinTypeNames;
  * or the child type for single index access.
  */
 @("*arr*") istring ARRAY_SYMBOL_NAME;
+/**
+ * In breadcrumbs this is a single entry meaning that the type following this
+ * started with a dot `.`, so module scope instead of local scope is to be used
+ * for type resolution.
+ *
+ * Note that auto-completion does not rely on this symbol, only type / symbol
+ * lookup relies on this.
+ */
+@("*arr*") istring MODULE_SYMBOL_NAME;
 /**
  * Type suffix, in breadcrumbs this is a single entry.
  *

dsymbol/src/dsymbol/conversion/first.d

@@ -1358,6 +1358,10 @@ void writeIotcTo(T)(const TypeIdentifierPart tip, ref T output) nothrow
 {
 	if (!tip.identifierOrTemplateInstance)
 		return;
+
+	if (tip.dot)
+		output.insert(MODULE_SYMBOL_NAME);
+
 	if (tip.identifierOrTemplateInstance.identifier != tok!"")
 		output.insert(internString(tip.identifierOrTemplateInstance.identifier.text));
 	else

dsymbol/src/dsymbol/conversion/second.d

@@ -263,7 +263,14 @@ do
 				getSymbolFromImports(imports, part);
 			else
 			{
-				auto symbols = moduleScope.getSymbolsByNameAndCursor(part, symbol.location);
+				auto symbols = part == MODULE_SYMBOL_NAME
+					? {
+						assert(!breadcrumbs.empty);
+						part = breadcrumbs.front;
+						breadcrumbs.popFront();
+						return moduleScope.getSymbolsByName(part);
+					}()
+					: moduleScope.getSymbolsByNameAndCursor(part, symbol.location);
 				if (symbols.length > 0)
 					currentSymbol = symbols[0];
 				else

tests/tc_casts/file.d

@@ -24,3 +24,11 @@ unittest
 	auto from_cast = cast(A.B.C) nonExist;
 	from_cast.
 }
+
+unittest
+{
+	struct A {}
+
+	auto from_cast = cast(.A.B.C) nonExist;
+	from_cast.
+}

tests/tc_casts/run.sh

@@ -6,3 +6,6 @@ diff actual1.txt expected1.txt --strip-trailing-cr
 
 ../../bin/dcd-client $1 file.d -c239 > actual2.txt
 diff actual2.txt expected2.txt --strip-trailing-cr
+
+../../bin/dcd-client $1 file.d -c320 > actual3.txt
+diff actual3.txt expected1.txt --strip-trailing-cr