Re: [RFC] Generalize support of negative string offsets

Christoph Becker wrote on 11/02/2016 12:16:

Appending to an array always adds a single element only, consider $a = [1,2,3]; $a[] = [4,5]; The suggested syntax for strings would concatenate an arbitrary amount of elements (characters) to a string. IMHO, this would not be consistent, but rather confusing. The alternative interpretation to append the first character only, would be confusing as well (besides there would be issues with regard to multibyte character encodings).

Indeed, this is a big problem with making the string offset functionality richer in general, because PHP has no "char" type, only a single-character string. This leads to some odd things: // string[0] returns a one-char string, which has an element [0], so you can keep adding [0] for as long as you like: $foo = 'abc'; echo $foo[0][0][0][0][0]; // a // assignment to an offset only overwrites one character, but the source can be a string of any length: $foo = 'abc'; $foo[0] = 'zzz'; echo $foo; // zbc String offsets simply can't behave like array offsets within PHP's current type system, which is why I favour dedicating {} syntax to them, and making it work *usefully*, rather than trying to make it look like arrays. Then, it would be less surprising for $string{-1} to behave differently from $array[-1], and that $string{} is a syntax error. Regards, -- Rowan Collins [IMSoP]