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On 26/08/15 08:53 PM, Hisham wrote:

On 26 August 2015 at 16:27, Soni L. <fakedme@gmail.com> wrote:


On 26/08/15 04:24 PM, Dirk Laurie wrote:

2015-08-24 18:07 GMT+02:00 steve donovan <steve.j.donovan@gmail.com>:

On Fri, Aug 21, 2015 at 4:04 PM, Coda Highland <chighland@gmail.com>
wrote:

I think C++11's way of defining new literals is pretty reasonable. You
define a suffix operator (which must start with _) and when literals
appear with that suffix, it's translated at compile time (in Lua's
case, bytecode generation time) to a call to that function

But (and this is crucial) any resulting object creation is not hoisted
out. For instance, in languages with regexp literals /.../, the
literal is replaced with a reference to a compiled regexp object.
They effectively become constants.  If I see a 'date literal' like
D'2015-08-24' in Lua I know that this string will be parsed _each
time_ - it isn't really a literal.

Code generation for true custom literals would get pretty involved.  I
don't think the prettiness is worth the bother.

Not at all, assuming that Roberto's suggestion of per-value
metatables gets implemented. A user-defined literal would
be implemented as a string with a metatable. It could work
this way:

I'd rather have multiple levels of metatables.

Value level
Scope level
Function level
Module level
Global level

Including for tables so that you can t = {} t:insert(v) and it just works.

...until you do something like

    users[name] = data

where name happens to be "insert"...

-- Hisham


Don't you have that caveat with the current metatable system, anyway?

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