Re: [OE vs Phix] assigning atom to a slice is different
- Posted by petelomax Feb 15, 2018
- 1253 views
Sorry, I forgot that self-hosting is broken on linux (or rather libc.so.6/system is throwing error code 32512 which makes no sense). I've rebuilt and uploaded the compiler, so the following should do the trick:
wget http://phix.x10.mx/p32 mv p32 phix/p
and I have now pushed that change to the repository.
--string s = "fed" seq s = "fed" s[2..2] = "ee" -- s is now "feed" -- given seq p = "ee" s[2] = p -- s is now "'f',"ee",'d'" ? --type check failure, s is {102,"ee",101,100} when s is string ?s -- s is now {'f',"ee",'e','d'} s[2..3] = "12" -- s is now "f12" ? ?s -- s is now {'f','1','2','d'} s[2..-2] = "12" -- s is now "f21d" ? ?s -- s is now {'f','1','2','d'}
Some operations on a string must auto-expand it to a dword-sequence; obviously that proved necessary for compatibility reasons. There is no such thing as an auto-compact.
Note that you can do pretty much anything with {'f','1','2','d'} that you can do with "f12d", obviously apart from storing it in a string variable, and compare({'f','1','2','d'},"f12d") yields 0 (equal), however they are quite different internally.
s[2..-2] is exactly the same as s[2..3] for a length 4 sequence, it does not reverse the slice being copied, dunno what made you think that.
A real-world example of this being useful could be a template letter containing "Dear [name],\nThank you for..." and you want to put the actual name in there.
For some online docs see http://phix.x10.mx/docs/html/slices.htm
Ultimately s[i..j] = rep is just a shorthand for s = s[1..i-1] & rep & s[j+1..$]
If it cannot do it in situ (eg because the lengths differ) then that is pretty much what it does internally, not significantly more difficult than what say a &= b has to do.
