Re: significance of newline in io?

The genius of Io though, which distinguishes it from other languages with newlines-terminate-expressions is that Io treats lines following an unmatched left-parens ( as part of one expression until the parens is closed.

That's what allows syntax like:

f := method(arg1, arg2,
   writeln(
      arg1,
      arg2
   )
)

Instead of "writeln(" generating an error on the newline as similar syntax would in e.g. a BASIC-dialect, it's just implicit that you want to continue the expression on multiple lines.  So you don't need a line continuation character, just parenthesis.

This, on the other hand, would not work:

f := method
(
   arg1, arg2,
   writeln
      (arg1, arg2)
)

--- In [email protected], Steve Dekorte <steve@...> wrote:
>
> A newline in Io is like a semicolon in C - it ends the expression and returns the evaluation scope to the locals.
> 
> 
> 
> On Aug 7, 2011, at 8:05 PM, Paul Sanwald <pcsanwald@...> wrote:
> 
> > 
> > 
> > working through "7 languages in 7 weeks", I noticed something interesting. This method definition me an error when invoking:
> > Object ancestors := method(
> >     prototype := self proto
> >     if (prototype != Object,
> >         writeln("Slots of ",prototype type,"\n-------")
> >         prototype slotNames foreach(slotName, writeln(slotName))
> >         writeln prototype ancestors))
> > 
> > Whereas, this definition does not:
> > 
> > Object ancestors := method(
> >     prototype := self proto
> >     if (prototype != Object,
> >         writeln("Slots of ",prototype type,"\n-------")
> >         prototype slotNames foreach(slotName, writeln(slotName))
> >         writeln 
> >         prototype ancestors))
> > 
> > the only difference here is the newline after "writeln". what is the significance of the newline in the language? am I missing something in the docs?
> > 
> > thanks for your help!
> > 
> > --paul
> > 
> > 
> >
>