Re: Function definitions in table constructors
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- Subject: Re: Function definitions in table constructors
- From: Edgar Toernig <froese@...>
- Date: 2008年2月22日 00:25:15 +0100
Miles Bader wrote:
>
> Mark Hamburg <mhamburg@adobe.com> writes:
> >> so table-constructor methods have a lightweight syntax.
> >
> > But to really make it pay off one needs some way to also remove the need for
> > a comma after the end.
>
> Yeah, I've always found the need for "," or ";" inside table
> constructors inside tables annoying... Do things become overly
> ambiguous without them though?
I have that in my Lua dialect and there are some pitfalls but
I never stepped into one. I usually use commas but omit them
when they are annoying, i.e. after function statements.
IMHO, if you can manage the different precedences of + and * you
can handle this, too.
Excerpt from http://goron.de/~froese/sol/Diffs2Lua
---snip---
- Commas and semicolons are optional but may be used to
avoid ambiguities. There's no semantic difference
between a comma and a semicolon.
{ a=1 b=2 c=3, d=4; e=5;,; 32 f, (1+2)*3 }
Be careful when a field is followed by a string constant,
a table constructor, or a parenthesized or negated
expression:
{ f "foo" } vs { f, "foo" }
{ {} {} } vs { {}, {} }
{ a=1 (2+3) } vs { a=1, (2+3) }
{ a=1 -2 } vs { a=1, -2 }
It's recommended to be not too economic with commas ;-)
- Named functions may be used as rec-fields:
{
function foo() .... end
function bar() .... end
}
---snip---
Ciao, ET.