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1. Re: Suggestion: Deprecate "Attempt to index a nil value" error; instead, return nil or create table (score: 643)

Author: Coda Highland <chighland@...>

Date: Fri, 28 Feb 2020 17:10:03 -0600

On Fri, Feb 28, 2020 at 3:59 PM Anton Jordaan <anton.jordaan@sylvean.com> wrote: Lua is memory efficient for huge but sparse multi-dimensional arrays, since nil values aren't stored in the tables. Ho

2. Re: Suggestion: Deprecate "Attempt to index a nil value" error; instead, return nil or create table (score: 635)

Author: Dennis Fischer <darkwiiplayer@...>

Date: Sun, 1 Mar 2020 11:39:21 +0000

Wouldn't it be enough to write a function to do this type-checking for you instead of having the language *always* do it? ? Doing this would make debugging harder, as error messages wouldn't tell you

3. Re: Suggestion: Deprecate "Attempt to index a nil value" error; instead, return nil or create table (score: 626)

Author: Sam Putman <atmanistan@...>

Date: Tue, 3 Mar 2020 18:56:48 -1000

On Fri, Feb 28, 2020 at 11:59 AM Anton Jordaan <anton.jordaan@sylvean.com> wrote: Lua is memory efficient for huge but sparse multi-dimensional arrays, since nil values aren't stored in the tables. H

4. Re: Suggestion: Deprecate "Attempt to index a nil value" error; instead, return nil or create table (score: 624)

Author: Philippe Verdy <verdyp@...>

Date: Sat, 29 Feb 2020 19:24:36 +0100

Hmmm.. yes, but still "or nil" is not needed. For such situation, where you expect a function to return a value or an exception to catch in order to use an alternate (nil) value, I'd use a utility fu

5. Re: Suggestion: Deprecate "Attempt to index a nil value" error; instead, return nil or create table (score: 618)

Author: Sam Putman <atmanistan@...>

Date: Tue, 3 Mar 2020 19:07:17 -1000

On Tue, Mar 3, 2020 at 6:56 PM Sam Putman <atmanistan@gmail.com> wrote: On Fri, Feb 28, 2020 at 11:59 AM Anton Jordaan <anton.jordaan@sylvean.com> wrote: Lua is memory efficient for huge but sparse m

6. Re: Suggestion: Deprecate "Attempt to index a nil value" error; instead, return nil or create table (score: 618)

Author: connor horman <chorman64@...>

Date: Sat, 29 Feb 2020 13:25:35 -0500

actually it'll be the string "attempt to index a nil value"

7. Re: Deprecate "Attempt to index a nil value" error; instead, return nil or create table (score: 617)

Author: nobody <nobody+lua-list@...>

Date: Sun, 1 Mar 2020 23:04:33 +0100

On 01/03/2020 16.46, Philippe Verdy wrote: Or may be there's a need to subclass the "nil" value: reading an unassigned position in a table with this property could return this special "niltable" valu

8. Suggestion: Deprecate "Attempt to index a nil value" error; instead, return nil or create table (score: 612)

Author: Anton Jordaan <anton.jordaan@...>

Date: Fri, 28 Feb 2020 23:59:20 +0200

Lua is memory efficient for huge but sparse multi-dimensional arrays, since nil values aren't stored in the tables. However, reading and writing to such sparse multi-dimensional arrays can be quite a

9. Re: Suggestion: Deprecate "Attempt to index a nil value" error; instead, return nil or create table (score: 610)

Author: "Soni \"They/Them\" L." <fakedme@...>

Date: Sat, 29 Feb 2020 15:06:52 -0300

_, v = pcall(function() return t[a][b][c][d][e] end) i.e. discard (_) the false/true status in the 1st return value of the pcall, use the second value which is explicitly returned and will be nil if

10. Re: Deprecate "Attempt to index a nil value" error; instead, return nil or create table (score: 609)

Author: Anton Jordaan <anton.jordaan@...>

Date: Tue, 3 Mar 2020 13:52:23 +0200

Sean Conner wrote: Here are some of the issues that need to be addressed for this to work. 1) t[a] = v This is syntactic sugar for t = { [a] = v }. Then does that mean: local t[a] = v is legal Yes, l

11. Re: Suggestion: Deprecate "Attempt to index a nil value" error; instead, return nil or create table (score: 598)

Author: Philippe Verdy <verdyp@...>

Date: Sat, 29 Feb 2020 17:56:18 +0100

I see no value at all in adding "or nil" (except that you'll change a "false" stored value, returned without exception, into an "nil"). Then why do you need "and t[a][b][c][d][e]" ? Wouldn' this be e

12. Re: Suggestion: Deprecate "Attempt to index a nil value" error; instead, return nil or create table (score: 587)

Author: Philippe Verdy <verdyp@...>

Date: Fri, 6 Mar 2020 18:51:45 +0100

You reeate here exactly the idea I posted last week in this same thread (I spoke about the multikey function car can be used to map a set of keys into a single one, usiable as the main index of a sin

13. Re: Suggestion: Deprecate "Attempt to index a nil value" error; instead, return nil or create table (score: 587)

Author: "Soni \"They/Them\" L." <fakedme@...>

Date: Sat, 29 Feb 2020 13:42:41 -0300

the error when trying to index a null value is a good thing. Let's assume the statement v = t[a][b][c][d][e] Each of 5 indexing steps might result in nil. Sometimes you want to raise "Attempt to inde

14. Re: Deprecate "Attempt to index a nil value" error; instead, return nil or create table (score: 586)

Author: Philippe Verdy <verdyp@...>

Date: Sun, 1 Mar 2020 16:46:04 +0100

If such behavior is added, it should depend on a table's meta-property, i.e. a special value in its metatable. Autocreation can also create problems in Lua. Or may be there's a need to subclass the "

15. Re: Suggestion: Deprecate "Attempt to index a nil value" error; instead, return nil or create table (score: 584)

Author: Egor Skriptunoff <egor.skriptunoff@...>

Date: Sat, 29 Feb 2020 19:31:01 +0300

On Sat, Feb 29, 2020 at 5:42 PM Italo Maia wrote: the error when trying to index a null value is a good thing. Let's assume the statement v = t[a][b][c][d][e] Each of 5 indexing steps might result in

16. Re: Suggestion: Deprecate "Attempt to index a nil value" error; instead, return nil or create table (score: 583)

Author: Diego Nehab <diego@...>

Date: Fri, 6 Mar 2020 12:16:03 -0300

A while back Luiz Henrique and I brainstormed potential support for multi-index tables in Lua. The motivation was the binding multi-index C structures to Lua. Here is a summary of our conversation. C

17. Re: Suggestion: Deprecate "Attempt to index a nil value" error; instead, return nil or create table (score: 580)

Author: connor horman <chorman64@...>

Date: Sat, 29 Feb 2020 14:35:17 -0500

On Sat, Feb 29, 2020 at 14:29 Egor Skriptunoff <egor.skriptunoff@gmail.com> wrote: On Sat, Feb 29, 2020 at 9:26 PM connor horman wrote: I?ve used some strongly typed languages that have a ?try operat

18. Re: Suggestion: Deprecate "Attempt to index a nil value" error; instead, return nil or create table (score: 579)

Author: Sean Conner <sean@...>

Date: Sun, 1 Mar 2020 18:21:57 -0500

It was thus said that the Great Anton Jordaan once stated: Let's assume for a second this exists. Here are some of the issues that need to be addressed for this to work. 1) t[a] = v This is syntactic

19. Re: Suggestion: Deprecate "Attempt to index a nil value" error; instead, return nil or create table (score: 576)

Author: Egor Skriptunoff <egor.skriptunoff@...>

Date: Sat, 29 Feb 2020 22:29:17 +0300

On Sat, Feb 29, 2020 at 9:26 PM connor horman wrote: I?ve used some strongly typed languages that have a ?try operator?. t?[a]?[b]?[c]?[d]?[e] would be equivalent to t[a][b][c][d][e], but if any eval

20. Re: Suggestion: Deprecate "Attempt to index a nil value" error; instead, return nil or create table (score: 574)

Author: Coda Highland <chighland@...>

Date: Fri, 6 Mar 2020 16:44:55 -0600

On Fri, Mar 6, 2020 at 4:09 PM Diego Nehab <diego@impa.br> wrote: On Fri, Mar 6, 2020 at 18:19 Egor Skriptunoff <egor.skriptunoff@gmail.com> wrote: On Fri, Mar 6, 2020 at 6:16 PM Diego Nehab wrote: I