Parsing postfix exprs: if we have '.<keyword><code_complete>', try to recover

by creating an identifier with the same spelling as the keyword.

Fixes code completion for cases like 'foo.is#^A^#'.


Swift SVN r6727

Author: gribozavr

lib/Parse/ParseExpr.cpp

@@ -838,6 +838,27 @@ NullablePtr<Expr> Parser::parseExprPostfix(Diag<> ID) {
     }
     if (consumeIf(tok::period) || (IsPeriod && consumeIf(tok::period_prefix))) {
       if (Tok.isNot(tok::identifier) && Tok.isNot(tok::integer_literal)) {
+        if (peekToken().is(tok::code_complete)) {
+          switch (Tok.getKind()) {
+          default:
+            break;
+
+#define KEYWORD(kw) \
+            case tok::kw_##kw:
+#include "swift/Parse/Tokens.def"
+            {
+              // If we have a '.<keyword><code_complete>', then try to recover
+              // by creating an identifier with the same spelling as the
+              // keyword.
+              Identifier Name = Context.getIdentifier(Tok.getText());
+              Result = new (Context) UnresolvedDotExpr(Result.get(), TokLoc,
+                                                       Name, Tok.getLoc());
+              consumeToken();
+            }
+            break;
+          }
+        }
+
         if (Tok.is(tok::code_complete) && CodeCompletion && Result.isNonNull()) {
           CodeCompletion->completeDotExpr(Result.get());
           return nullptr;