Re: Getting OrderedTable key/value pair by insertion order

[mratsim]

We're still waiting for your B-Trees implementation to have SortedTable in the 
standard lib ;)

Re: Getting OrderedTable key/value pair by insertion order

[squattingmonk]

> So indeed iterating over the keys and stopping after first one makes sense, I 
> think there is no function to retrieve the first added element. And I think I 
> can remember someone asking how to get the n-th. added element, conclusion 
> was to use a loop similar as you do.

Thanks, Stefan. I'd though I was just being silly and missing something 
obvious. Good to know this is a reasonable solution.

> use 
> 
> 
> iterator pairs[A, B](t: OrderedTable[A, B]): (A, B)
> 
> 
> Run
> 
> and break-out after first (does "... in insertion order." kind of implies 
> FIFO?) element.

Hi, lucian. That's what I did in the code sample I provided, but I used the 
`keys` iterator instead of `pairs`.

Re: Getting OrderedTable key/value pair by insertion order

[Araq]

Ok, yeah, we have no api for that.

Re: Getting OrderedTable key/value pair by insertion order

[lucian]

use 


iterator pairs[A, B](t: OrderedTable[A, B]): (A, B)


Run

and break-out after first (does "... in insertion order." kind of implies 
FIFO?) element.

Re: Getting OrderedTable key/value pair by insertion order

[squattingmonk]

I'm not trying to get sorted items, just the first item added (hence why I used 
an OrderedTable).

Re: Getting OrderedTable key/value pair by insertion order

[Stefan_Salewski]

>From your last code sample, I think I understand that you want to retrieve the 
>table entry, that was added first to table. So indeed iterating over the keys 
>and stopping after first one makes sense, I think there is no function to 
>retrieve the first added element. And I think I can remember someone asking 
>how to get the n-th. added element, conclusion was to use a loop similar as 
>you do.

Re: Getting OrderedTable key/value pair by insertion order

[Araq]

I don't understand the question: An OrderedTable keeps the insertion order, 
it's not a "SortedTable" (which the stdlib still lacks)

Getting OrderedTable key/value pair by insertion order

[squattingmonk]

Hi, all! I'm trying to get the first item out of an OrderedTable that was 
indexed with strings. I'm not sure which is the best way to do it.

My program is reading a set of configuration files and loading the information 
into a type `Target`, which is then added to an ordered table using the name of 
the target as its index. If the user executes a command that takes a target, I 
want to get the target using the supplied name as the index (just normalized). 
So far, so good. However, if the user does not specify a target, I want to 
select the first one that was added to the table.

Here's my types: 


type
  Config* = object
# ...
targets*: OrderedTable[string, Target]
  
  Target = object
name*, file*, description*: string
sources*: seq[string]


Run

This is the only way I can think of to get the first index: 


if opts.target.len == 0:
  for target in cfg.targets.keys:
opts.target = target
break
 

Run

Is there a better way of getting the first index? Or maybe a better way to 
structure my data that avoids this?

Thanks!