Re: [PATCH] diff-options: add --patch-with-stat

Johannes Schindelin <Johannes.Schindelin@gmx.de> writes:

While I think combined diffs are somewhat overrated, I think what makes some sense would be to count --cc output for each parent's column, and show something like this:

 Makefile            | +-     +- 
 debian/changelog    | ++++++ ++++++++++++++++++++
 2 files changed, 7 and 91 insertions(+), 1 and 0 deletions(-)

This is for "diff-tree --cc v1.0.0"; the hand-merge (or evil merge) changed from first parent 7(+),1(-) and from second parent 91(+),0(-) respectively.

Count the maximum change per each parent (the above example the second file has the max for both parents but that may not always be the case), add them up to determine how many columns to allocate for each parent (while taking one column gap between each parent into account) and draw normally.

The code that counted this (I did not write code to draw it) is like this:

-- >8 -- #!/usr/bin/perl

use strict; my $filename; my $num_parents = -1; my %stat;

while (<>) {
	chomp;
	if (/^diff --cc (.*)$/) {
		$filename = $1;
		$stat{$filename} = undef;
		next;
	}
	if (/^(\@+) [-+0-9, ]* \1$/) {
		$num_parents = length($1) - 1;
		next;
	}
	next unless (/^([- +]{$num_parents})/);
	my @pfx = split('', $1);
	if (!defined $stat{$filename}) {
		$stat{$filename} = [];
		for (my $i = 0; $i < $num_parents; $i++) {
			push @{$stat{$filename}}, [0, 0];
		}
	}
	for (my $i = 0; $i < $num_parents; $i++) {
		if ($pfx[$i] eq '+') {
			$stat{$filename}[$i][0]++;
		}
		if ($pfx[$i] eq '-') {
			$stat{$filename}[$i][1]++;
		}
	}
}

for my $filename (sort keys %stat) {
	print "$filename	";
	for (my $i = 0; $i < $num_parents; $i++) {
		printf " +%d/-%d",
		$stat{$filename}[$i][0], $stat{$filename}[$i][1];
	}
	print "\n";
}