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From: Junio C Hamano <gitster@pobox•com>
To: git@vger•kernel.org
Subject: [PATCH 9/8] CodingGuidelines: on splitting a long line
Date: Fri, 02 May 2014 13:51:55 -0700	[thread overview]
Message-ID: <xmqqiopnaopg.fsf@gitster.dls.corp.google.com> (raw)
In-Reply-To: <1398894312-30763-1-git-send-email-gitster@pobox.com> (Junio C. Hamano's message of "Wed, 30 Apr 2014 14:45:04 -0700")


Signed-off-by: Junio C Hamano <gitster@pobox•com>
---
 Documentation/CodingGuidelines | 55 ++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 55 insertions(+)

diff --git a/Documentation/CodingGuidelines b/Documentation/CodingGuidelines
index 02ca67c..4dd07c3 100644
--- a/Documentation/CodingGuidelines
+++ b/Documentation/CodingGuidelines
@@ -249,6 +249,61 @@ For C programs:
    Just do not mix styles in the same part of the code and mimic
    existing styles in the neighbourhood.
 
+ - There are two schools of thought when it comes to splitting a long
+   logical line into multiple lines.  Some people push the second and
+   subsequent lines far enough to the right with tabs and align them:
+
+        if (the_beginning_of_a_very_long_expression_that_has_to ||
+		span_more_than_a_single_line_of ||
+		the_source_text) {
+                ...
+
+   while other people prefer to align the second and the subsequent
+   lines with the column immediately inside the opening parenthesis,
+   with tabs and spaces, following our "tabstop is always a multiple
+   of 8" convention:
+
+        if (the_beginning_of_a_very_long_expression_that_has_to ||
+	    span_more_than_a_single_line_of ||
+	    the_source_text) {
+                ...
+
+   Both are valid, and we use both.  Again, just do not mix styles in
+   the same part of the code and mimic existing styles in the
+   neighbourhood.
+
+ - When splitting a long logical line, some people change line before
+   a binary operator, so that the result looks like a parse tree when
+   you turn your head 90-degrees counterclockwise:
+
+        if (the_beginning_of_a_very_long_expression_that_has_to
+	    || span_more_than_a_single_line_of_the_source_text) {
+
+   while other people prefer to leave the operator at the end of the
+   line:
+
+        if (the_beginning_of_a_very_long_expression_that_has_to ||
+	    span_more_than_a_single_line_of_the_source_text) {
+
+   Both are valid, but we tend to use the latter more, unless the
+   expression gets fairly complex, in which case the former tends to
+   be easier to read.  Again, just do not mix styles in the same part
+   of the code and mimic existing styles in the neighbourhood.
+
+ - When splitting a long logical line, with everything else being
+   equal, it is preferrable to split after the operator at higher
+   level in the parse tree.  That is, this is more preferrable:
+
+	if (a_very_long_variable * that_is_used_in +
+	    a_very_long_expression) {
+		...
+
+   than
+
+	if (a_very_long_variable *
+	    that_is_used_in + a_very_long_expression) {
+		...
+
  - Some clever tricks, like using the !! operator with arithmetic
    constructs, can be extremely confusing to others.  Avoid them,
    unless there is a compelling reason to use them.
-- 
2.0.0-rc1-355-gd6d6511

  parent reply	other threads:[~2014-05-02 20:52 UTC|newest]

Thread overview: 30+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2014-04-30 21:45 [PATCH 0/8] Update the CodingGuidelines Junio C Hamano
2014-04-30 21:45 ` [PATCH 1/8] CodingGuidelines: typofix Junio C Hamano
2014-05-01 14:09   ` David Kastrup
2014-05-01 17:51     ` Junio C Hamano
2014-05-01 21:27       ` Jeff King
2014-05-02 18:31         ` Junio C Hamano
2014-05-02 20:33           ` Jeff King
2014-05-02 20:37             ` Felipe Contreras
2014-05-02 20:53               ` David Kastrup
2014-04-30 21:45 ` [PATCH 2/8] CodingGuidelines: give an example for case/esac statement Junio C Hamano
2014-04-30 21:45 ` [PATCH 3/8] CodingGuidelines: give an example for redirection Junio C Hamano
2014-04-30 22:14   ` [PATCH v2 " Junio C Hamano
2014-04-30 21:45 ` [PATCH 4/8] CodingGuidelines: give an example for control statements Junio C Hamano
2014-04-30 21:54   ` Stefan Beller
2014-04-30 22:03     ` Junio C Hamano
2014-05-01 14:12   ` David Kastrup
2014-05-01 18:00     ` Junio C Hamano
2014-04-30 21:45 ` [PATCH 5/8] CodingGuidelines: give an example for shell function preamble Junio C Hamano
2014-04-30 21:45 ` [PATCH 6/8] CodingGuidelines: call the conditional statement "if ()", not "if()" Junio C Hamano
2014-05-01 14:14   ` David Kastrup
2014-05-01 18:11     ` Junio C Hamano
2014-05-01 18:36       ` David Kastrup
2014-04-30 21:45 ` [PATCH 7/8] CodingGuidelines: on comparison Junio C Hamano
2014-05-01 21:36   ` Jeff King
2014-05-02 18:18     ` Junio C Hamano
2014-05-02 20:31       ` Jeff King
2014-05-02 20:45         ` Junio C Hamano
2014-04-30 21:45 ` [PATCH 8/8] CodingGuidelines: once it is in, it is not worth the code churn Junio C Hamano
2014-05-02 20:51 ` Junio C Hamano [this message]
2014-05-02 21:00   ` [PATCH 9/8] CodingGuidelines: on splitting a long line brian m. carlson

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