[Wish] One line while loop (similar to if)

[HotKeyIt]

I suggest to reserve return, break and continue only and do not allow (x(), break).
Only those 3 should be supported in if x, y(), return z, everything else must be an expression.

[Guest_20151017]

I really doubt that it's about there being less typing, either way.

I agree. I'm gonna go out on a limb & say it's because of the restrictions on how you can write your syntax (not un-similar to complaints against python). I don't want to add another line to my code - I want the simple condition & action on the same line - especially if I'm in a One-Liner type of mood. This becomes extremely important when I'm trying to write beautiful, condensed code - or just trying to impress others with my sophisticated coding skills.

... of course I'm being sarcastic, yet truthful ...

Anyways, I'm gonna jump the gun & say why not take the perl approach and allow:

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action if conditon
; or
action while condition

That perl approach seems a bit backwards to me for putting the while and if toward the back, which isn't what happens in the non-one liners. I can see until being done like that though.

[sirksel]

Implementing the following is trivial:

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while condition, statement
for var in expression, statement
for var1, var2 in expression, statement
expression, statement  ; as in:
x(), return y
; even:
if x, y(), else, z()

It is less trivial to intuitively group the statements, as in if x, y(), return z grouping the last two in a block (or likewise when below an if/loop/etc.).

I may not be understanding, but I think what you've outlined above is useful (at least for me) just by itself, without any grouping functionality. I think, currently, all of these commands support a single unblocked statement immediately following the line (e.g., if you want to omit the braces), right? In that case, if I just want to use a single line with no braces I already can't have multiple statements on that line. I can have multiple assignments/expressions, but not multiple statements, correct? Even so, I use this no-braces option all the time for simple constructs. Isn't this proposal then just allowing that line to be moved up to the same line as the while, with all the same restrictions that would be there if this were a one-liner (unbraced) block?

For me, it would help a lot. I have lots of terse utility functions that are not that complicated to understand, and for these, compact is better. So, for example, ...

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while count<=max,  execute(count++)
;is better (for me) than
while count<=max
	execute(count++)
;the extra line doesn't really help things that much if the construct is simple.

If (i) it's just an optional thing for those who want/need it, (ii) it already mirrors the restrictions that are present in the one-liner (unbraced) form, and (iii) it's trivial to implement, I'd really appreciate it if you would include it when you have time. I, for one, would use it a great deal for simple functions. Thanks again!

[lexikos]

Being "useful" isn't enough. AutoHotkey v1 is already useful as it is. v2 is not about making the language more useful. A large part of it is about eliminating sources of confusion. Some of these sources of confusion are special rules within the language which were intended to make it more useful but end up creating inconsistency, like x := 1, y = 2 allowing = to assign an expression.

If if x, y(), return z was interpreted as

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if x
    y()
return z

that would be a source of confusion. The grouping problem is specific to expression, statement, which would be one way of allowing if condition, expression, else, statement. Obviously, the others could be allowed without this.

Allowing expression, statement but not SomeCommand, % expression, statement could be another source of confusion. Allowing the latter - with restrictions like "must be after the last parameter of the command" - would create more complication (harder to understand, remember, implement...).

In C-like languages, the return in if (x) y(); return z; does not belong to the if, but in those languages, the semicolon is clearly a statement separator, never used to delimit parameters or sub-expressions. In AutoHotkey, if x (newline) y(), z() works just fine because y(), z() is a single expression with the comma ("multi-statement") operator. But if expression, statement was allowed and simply treated as two separate lines (no block/grouping), either y(), return z() and y(), z() would be inconsistent, or worse, if x, y(), z() would be interpreted as

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if x
    y()  ; conditional upon x
z()  ; unconditional

Allowing catch, var, statement would create another source of confusion, because someone is bound to write something like catch, return, where return is a variable intended as a statement.


In this case, the "usefulness" is subjective, and I think probably not in favour of the "non-programmers" who are ostensibly the main target of AutoHotkey.

[BGM]

I always wanted the option to write loops on one line, too. It would help me organize my code better, and for me, at least, to read it more easily, especially for short loops like what fincs offered as an example above.

[_3D_]

In many sources We see next style:

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if (expression) {
	oneonlyline();
}

Same-line syntax prevent further editing of script and made source less readable.
In other case parsing become more complicated.

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if expressinon1, expression2, action1, action2

Same-line but what will be the result?

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if(expression1, expression2)
	action1, action2 ;same-line 2 actions

OR

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if(expressinon1, expression2, action1, action2)
	"" ; the action

OR

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if(expressinon1)
	expression2, action1, action2 ;same-line 3 actions

Removing same-line in IF syntax separate expressions from actions by default.