My current favorite example of this (ignoring the naming scheme for string functions entirely) is that in_array and strpos are functions that perform (almost) the same task, on two different types. They take their arguments in the opposite order. strpos($haystack, $needle) vs in_array($needle, $haystack).
You never asked yourself WHY. See, that's the important question, isn't it. WHY.
I'll tell you WHY. Because two different dudes implemented it. At different times. Probably, from different continents. They didn't notice it at the time.
But, eventually, someone noticed it. And then they did something really crazy. They didn't fix it. Because that would break the software already using those functions.
It's impossible to write a perfect language from the start. Hell, it's not possible to write a good language from the start. Things that you didn't see crop up and you have to add functionality. And sometimes, the way you added it isn't right ... at that point, you have two choices.
You can fuck your existing user-base up the ass, refactor your code, change the interface, and do it "right" ... or you can do everything you can to mitigate the damage, while keeping the interface the same.
I can pull up software I wrote 10 years ago and it'll still work. Perfectly. You can only say that about languages that do it right.
And guess what? Those languages, they always have lots of warts. Because someone made the hard choice and kept something that's ugly, instead of fucking over a shitload of people to make it pretty.
I'll take function over form any day.
I had a pretty good idea why that's how it is. I even completely agree with not changing it now. Backwards compatibility is important, no argument there.
That doesn't change that it's the sort of niggling annoyance that drives people to dislike the language.
Choose a convention (ie: always $haystack before $needle), find the methods that don't conform, and print deprecation messages for them, add their replacements.
Then in the next major release, remove the deprecated methods. Hell, you could even put the deprecations in in a module so that those who can't/won't update their code won't have to be left behind.
It may be impossible to write a good language from the start, but that shouldn't deter from fixing those mistakes.
PHP chooses to be ugly, over shafting its user-base by deprecating shit left and right. I like that. It tells me I can use it in a production setting.
The problem with a language that moves slowly is that if there's an opportunity, it might just miss it. I was working in PHP in the early days and every release brought features you wanted to use yesterday. Perhaps if PHP didn't have the huge rate of change it did then maybe it would have never caught on. Python is several years older than PHP and yet it didn't come to web until long after.
function my_in_array($haystack, $needle) { return in_array($needle, $haystack); }
or whatever, and be done with it...
You're not really helping your cause here.
