Why is split(' ') trying to be (too) smart?
implementation, ruby, split, string
Solution
It's consistent with Perl's `split()` behavior. Which in turn is based on Gnu `awk`'s `split()`. So it's a long-standing tradition with origins in Unix.
From the perldoc on `split`:
As another special case, split emulates the default behavior of the command line tool awk when the PATTERN is either omitted or a literal string composed of a single space character (such as ' ' or "\x20" , but not e.g. / / ). In this case, any leading whitespace in EXPR is removed before splitting occurs, and the PATTERN is instead treated as if it were /\s+/ ; in particular, this means that any contiguous whitespace (not just a single space character) is used as a separator. However, this special treatment can be avoided by specifying the pattern / / instead of the string " " , thereby allowing only a single space character to be a separator.
Problem
I just discovered the following odd behavior with `String#split`: ``` "a\tb c\nd".split => ["a", "b", "c", "d"] "a\tb c\nd".split(' ') => ["a", "b", "c", "d"] "a\tb c\nd".split(/ /) => ["a\tb", "c\nd"] ``` The source (string.c from 2.0.0) is over 200 lines long and contains a passage like this: ``` /* L 5909 */ else if (rb_enc_asciicompat(enc2) == 1) { if (RSTRING_LEN(spat) == 1 && RSTRING_PTR(spat)[0] == ' '){ split_type = awk; } } ``` Later, in the code for the `awk` split type, the actual argument isn't even used any more and does the same as a plain `split`. - Does anyone else feel that this is somehow broken? - Are there good reasons for this? - Does “magic” like that happen more often than most people might think in Ruby?