[PATCH v3 0/1] MR10343: Draft: vbscript: Document expected parser conflicts with %expect 10.

[Francis De Brabandere (＠francisdb)]

The 10 shift/reduce conflicts are inherent ambiguities where bison's
default shift gives the correct behavior: colon chains extend greedily,
and Else/End If bind to the innermost inline If (dangling-else rule).

--
  v3: vbscript: Document expected parser conflicts with %expect 10.
 
https://gitlab.winehq.org/wine/wine/-/merge_requests/10343

[PATCH v3 1/1] vbscript: Document expected parser conflicts with %expect 10.

[Francis De Brabandere]

From: Francis De Brabandere <[e-mail]>

The 10 shift/reduce conflicts are inherent ambiguities where bison's
default shift gives the correct behavior: colon chains extend greedily,
and Else/End If bind to the innermost inline If (dangling-else rule).
---
 dlls/vbscript/parser.y | 17 +++++++++++++++++
 1 file changed, 17 insertions(+)

diff --git a/dlls/vbscript/parser.y b/dlls/vbscript/parser.y
index 4977358b333..97badf7593f 100644
--- a/dlls/vbscript/parser.y
+++ b/dlls/vbscript/parser.y
@@ -93,6 +93,23 @@ static statement_t *link_statements(statement_t*,statement_t*);
 %define api.pure
 %start Program
 
+/* 10 expected shift/reduce conflicts, all resolved correctly by bison's
+ * default shift:
+ *
+ * - 5 from colon chains: ':' can extend the current statement list or
+ *   start a new one in SourceElements, inline If bodies, and Else bodies;
+ *   shifting (greedy extension) gives the correct behavior.
+ *
+ * - 2 classic dangling Else / End If: "If a Then If b Then x Else y"
+ *   and "If a Then If b Then x End If" where Else / End If binds to
+ *   the innermost If.
+ *
+ * - 3 from End If / colon after inline If-Else: "If a Then If b Then
+ *   x Else y End If" and similar; End If and ':' bind to the innermost
+ *   If-Else.
+ */
+%expect 10
+
 %union {
     const WCHAR *string;
     statement_t *statement;
-- 
GitLab

https://gitlab.winehq.org/wine/wine/-/merge_requests/10343