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Why map return [] ?
Apr 14, 2017
Suliman
Apr 14, 2017
cym13
Apr 14, 2017
Suliman
Apr 14, 2017
Suliman
Apr 14, 2017
Rene Zwanenburg
Apr 14, 2017
Suliman
April 14, 2017
Gravatar of SulimanPosted by SulimanReply
Suliman
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auto x = MySQLTablesRange.map!(a=>a);
writeln(x);

return: []

while next code:
MySQLTablesRange.each!(a=>a.writeln);

return data line by line.

Why?
April 14, 2017
Gravatar of cym13Posted by cym13
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On Friday, 14 April 2017 at 15:29:33 UTC, Suliman wrote:
> auto x = MySQLTablesRange.map!(a=>a);
> writeln(x);
>
> return: []
>
> while next code:
> MySQLTablesRange.each!(a=>a.writeln);
>
> return data line by line.
>
> Why?

What library is that supposed to be?
April 14, 2017
Gravatar of SulimanPosted by Suliman
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On Friday, 14 April 2017 at 15:35:15 UTC, cym13 wrote:
> On Friday, 14 April 2017 at 15:29:33 UTC, Suliman wrote:
>> auto x = MySQLTablesRange.map!(a=>a);
>> writeln(x);
>>
>> return: []
>>
>> while next code:
>> MySQLTablesRange.each!(a=>a.writeln);
>>
>> return data line by line.
>>
>> Why?
>
> What library is that supposed to be?

http://code.dlang.org/packages/mysql-native
April 14, 2017
Gravatar of SulimanPosted by Suliman
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On Friday, 14 April 2017 at 15:38:19 UTC, Suliman wrote:
> On Friday, 14 April 2017 at 15:35:15 UTC, cym13 wrote:
>> On Friday, 14 April 2017 at 15:29:33 UTC, Suliman wrote:
>>> auto x = MySQLTablesRange.map!(a=>a);
>>> writeln(x);
>>>
>>> return: []
>>>
>>> while next code:
>>> MySQLTablesRange.each!(a=>a.writeln);
>>>
>>> return data line by line.
>>>
>>> Why?
>>
>> What library is that supposed to be?
>
> http://code.dlang.org/packages/mysql-native

I found problem! ResultRange should be converted to array before it can be `map`ed
April 14, 2017
Gravatar of Rene ZwanenburgPosted by Rene Zwanenburg
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On Friday, 14 April 2017 at 15:49:00 UTC, Suliman wrote:
> I found problem! ResultRange should be converted to array before it can be `map`ed

That shouldn't be necessary. Can you post your complete code?
April 14, 2017
Gravatar of SulimanPosted by Suliman
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Suliman
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On Friday, 14 April 2017 at 15:55:13 UTC, Rene Zwanenburg wrote:
> On Friday, 14 April 2017 at 15:49:00 UTC, Suliman wrote:
>> I found problem! ResultRange should be converted to array before it can be `map`ed
>
> That shouldn't be necessary. Can you post your complete code?

ResultRange MySQLTablesRange = mysqlconnection.query(`SELECT table_name FROM information_schema.tables;`);
auto x = MySQLTablesRange.map!(a=>a[0].coerce!string.split("_")[1]);
writeln(x);

output: []
while: MySQLTablesRange.array.map!...

output result