optional end for single-expression, one-line block bodies

[StefanKarpinski]

E.g., allow these:

for i=1:10 println(i)

if condition() println("met")
else println("not met")

while x < n f(x*=2)

try ignore_me_if_i_fail()

Since we would still allow end on single-expression, one-line block bodies, this wouldn't break any code, but I think it really makes a lot of things like this look better. Compare to how the above have to be written now:

for i=1:10 println(i) end

if condition() println("met")
else println("not met")
end

while x < n f(x*=2) end

try ignore_me_if_i_fail() end

[johnmyleswhite]

Personally, I don't really like the single line if's, but would be up for some Ruby style

f(1.0) if true

[StefanKarpinski]

I was gung-ho for that a long time ago, but my ardor has cooled somewhat. A lot of people seem to find that very hard to read.

[pao]

I can't say I care for this. At least with the reversed-order Perl/Ruby style, you know that if you flip it you need to group the statements. This sounds as prone to error as the optional curlies around single-statement ifs in C.

[StefanKarpinski]

I'm not sure where the errors might come from. How do you mean? It's interesting to get feedback on this idea, which has kind of been bouncing around my brain for a while.

[johnmyleswhite]

I'm not sure about errors, but I find the optional curlies in C very confusing.

[StefanKarpinski]

I don't find the optional curlies confusing, but it did once screw me over badly in 1998. I've managed to remain unaffected by them since then.

[JeffBezanson]

Wow, that must have been a traumatic incident :)

[StefanKarpinski]

Worst bug hunt I've ever experienced. It took me a week to track down a single stray semicolon.

[pao]

Errors in editing, particularly editing code you're not familiar with. https://www.google.com/search?q="optional+curly+braces"+problem gives a few links, and I know I've run into this in C myself. It just seems like a hair too much rope just to make short lines even shorter.

If you wanted that, you should have gone with layout instead of begin..end.

Also: pesky semicolon. Been there, done that too.

[goszlanyi]

In Fortran only simple ifs without else clauses can be written on a single line without endif

if condition  do_something_useful
if condition  continue
if condition  break

are very useful and readable in my practice.
Could be useful here too.