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why there is a [] at the end of assocArray
Jan 19, 2022
michaelbi
Jan 19, 2022
Stanislav Blinov
Jan 19, 2022
michaelbi
Jan 19, 2022
jfondren
Jan 19, 2022
Ali Çehreli
Jan 19, 2022
MichaelBi
January 19, 2022
Gravatar of michaelbiPosted by michaelbiReply
michaelbi
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input:
00100
11110
10110
10111
10101
01111
00111
11100
10000
11001
00010
01010

code:
void main()
{
	foreach(line; File("input.txt").byLine.map!(a=>a.idup).array.transposed){
		auto sortgroup = line.array.strip.sort.group.assocArray;	
		writeln(sortgroup);
	}
}

output:
['1':7, '0':5]
['1':5, '0':7]
['1':8, '0':4]
['1':7, '0':5]
['1':5, '0':7]
[]

so why there is a [] at the end of assocArray printed? thanks.

January 19, 2022
Gravatar of Stanislav BlinovPosted by Stanislav Blinov
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Stanislav Blinov
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On Wednesday, 19 January 2022 at 13:15:35 UTC, michaelbi wrote:

> 
	foreach(line; > File("input.txt").byLine.map!(a=>a.idup).array.transposed)
>

so why there is a [] at the end of assocArray printed? thanks.

...because there's an empty line at the end of input.txt?

January 19, 2022
Gravatar of michaelbiPosted by michaelbi
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michaelbi
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On Wednesday, 19 January 2022 at 13:21:32 UTC, Stanislav Blinov wrote:

>

On Wednesday, 19 January 2022 at 13:15:35 UTC, michaelbi wrote:

> 
	foreach(line; > File("input.txt").byLine.map!(a=>a.idup).array.transposed)
>

so why there is a [] at the end of assocArray printed? thanks.

...because there's an empty line at the end of input.txt?

i got it, though i still don't know where the [] come from. i just add strip here: a=>a.idup.strip

January 19, 2022
Gravatar of jfondrenPosted by jfondren
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jfondren
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On Wednesday, 19 January 2022 at 14:06:45 UTC, michaelbi wrote:

>

i got it, though i still don't know where the [] come from.

$ rdmd --eval 'writeln("".array.strip.sort.group.assocArray)'
[]
$ rdmd --eval 'writeln(typeid("".array.strip.sort.group.assocArray))'
uint[dchar]

It's what an empty AA looks like.

January 19, 2022
Gravatar of Ali ÇehreliPosted by Ali Çehreli
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Ali Çehreli
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On 1/19/22 06:06, michaelbi wrote:
> On Wednesday, 19 January 2022 at 13:21:32 UTC, Stanislav Blinov wrote:
>> On Wednesday, 19 January 2022 at 13:15:35 UTC, michaelbi wrote:
>>
>>>         foreach(line; > File("input.txt").byLine.map!(a=>a.idup).array.transposed)
>>
>>> so why there is a [] at the end of assocArray printed? thanks.
>>
>> ...because there's an empty line at the end of input.txt?
> 
> i got it, though i still don't know where the [] come from. i just add strip here: a=>a.idup.strip

Works for me on Linux. Perhaps there is an issue with Windows line endings?

In any case, the .strip above would not be eliminating empty lines; you need to filter them out e.g. with

  byLine.filter!(line => !line.empty)

Aside: Instead of copying the lines with .idup explicitly, there is .byLineCopy that already does that.

Ali
January 19, 2022
Gravatar of MichaelBiPosted by MichaelBi
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MichaelBi
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On Wednesday, 19 January 2022 at 16:36:36 UTC, Ali Çehreli wrote:
> On 1/19/22 06:06, michaelbi wrote:
>> On Wednesday, 19 January 2022 at 13:21:32 UTC, Stanislav Blinov wrote:
>>> On Wednesday, 19 January 2022 at 13:15:35 UTC, michaelbi wrote:
>>>
>>>> [...]
>>>
>>>> [...]
>>>
>>> ...because there's an empty line at the end of input.txt?
>> 
>> i got it, though i still don't know where the [] come from. i just add strip here: a=>a.idup.strip
>
> Works for me on Linux. Perhaps there is an issue with Windows line endings?
>
> In any case, the .strip above would not be eliminating empty lines; you need to filter them out e.g. with
>
>   byLine.filter!(line => !line.empty)
>
> Aside: Instead of copying the lines with .idup explicitly, there is .byLineCopy that already does that.
>
> Ali

I am using windows.
Thanks a lot for introducing those funcs. Now I am feeling the D’s quite interesting and powerful :)