Subject: [PATCH v3 30/35] userdiff golang: simplify and correct matching regex

From: Ævar Arnfjörð Bjarmason <[email-masked]>
Date: Wed, 24 Feb 2021 20:51:24 +0100

Simplify the regex for the golang driver added in
1dbf0c0ad6c (userdiff: add built-in pattern for golang, 2018-03-01) to
remove redundant constructs.

There's no point in having a regex like this:

    .*(foo)?

When we can just write:

    .*

In the "func" case, since the "(foo?)" match isn't mandatory it won't
matter for the end result, and in this case we're not using the
capture pattern. Not that it would matter since it's followed by a
greedy .*, so we'd only get the empty string.

In the "type" case we would stop at the "{", since it was not preceded
by a ".*". This was a bug, if we have a comment or something else on
that line we should include it.

I'm also changing the "func[ \t]*.*" rule to "func[ \t].*" while I'm
at it. We should always get whitespace after "func", so this narrows
down our match. Let's do the same in the new "type" rule.

Signed-off-by: Ævar Arnfjörð Bjarmason <[email-masked]>
---
 t/t4018/golang | 2 +-
 userdiff.c     | 4 ++--
 2 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/t/t4018/golang b/t/t4018/golang
index 70bf0d936bb..72a35d66008 100644
--- a/t/t4018/golang
+++ b/t/t4018/golang
@@ -46,7 +46,7 @@ type RIGHT struct {
 }
 
 t4018 description: struct with comment after {
-t4018 header: type some struct {
+t4018 header: type some struct { // comment
 type some struct { // comment
 	a Type
 	b ChangeMe
diff --git a/userdiff.c b/userdiff.c
index 55f4f769bd3..698eca5ad35 100644
--- a/userdiff.c
+++ b/userdiff.c
@@ -129,9 +129,9 @@ IPATTERN("fountain",
 	 "[^ \t-]+"),
 PATTERNS("golang",
 	 /* Functions */
-	 "^[ \t]*(func[ \t]*.*(\\{[ \t]*)?)\n"
+	 "^[ \t]*(func[ \t].*)\n"
 	 /* Structs and interfaces */
-	 "^[ \t]*(type[ \t].*(struct|interface)[ \t]*(\\{[ \t]*)?)",
+	 "^[ \t]*(type[ \t].*(struct|interface)[ \t].*)",
 	 /* -- */
 	 "[a-zA-Z_][a-zA-Z0-9_]*"
 	 "|[-+0-9.eE]+i?|0[xX]?[0-9a-fA-F]+i?"
-- 
2.30.0.284.gd98b1dd5eaa7