Or, shorter, sweeter and non-recursive (and kind of a restatement of
Your Mother's contribution):
perl -wMstrict -le
"sub standard_commas {
return @_ == 0 ? ''
: @_ == 1 ? qq{$_[0]}
: join q{, }, @_[0 .. $#_ - 2], qq{$_[-2] and $_[-1]}
}
sub oxford_commas {
return @_ < 3 ? standard_commas(@_)
: join q{, }, @_[0 .. $#_ - 1], qq{and $_[-1]}
}
for (@ARGV) {
my @words = split;
print qq(\nfor words: @words);
print 'standard commas: ', standard_commas(@words);
print ' oxford commas: ', oxford_commas(@words);
}
"
"" "a" "a b" "a b c" "a b c d" "a b c d e"
for words:
standard commas:
oxford commas:
for words: a
standard commas: a
oxford commas: a
for words: a b
standard commas: a and b
oxford commas: a and b
for words: a b c
standard commas: a, b and c
oxford commas: a, b, and c
for words: a b c d
standard commas: a, b, c and d
oxford commas: a, b, c, and d
for words: a b c d e
standard commas: a, b, c, d and e
oxford commas: a, b, c, d, and e