Hi All,

 It is possible to store struct in a array ans use the same in csvReader e.g.

import std.stdio;
import std.container.array;

void main () {
Array!string a;
struct Layout { string name; int value; double other; }

a.insert(Layout);
auto record =  uFile.byLineCopy().joiner("\n").csvReader!(Tuple!a[0]))
foreach (record; records)
{
    writeln(record.name);
    writeln(record.value);
    writeln(record.other);
}

From,
Vino.B

On Tuesday, 9 January 2018 at 13:49:41 UTC, Vino wrote:
> Hi All,
>
>  It is possible to store struct in a array ans use the same in csvReader e.g.
>
> import std.stdio;
> import std.container.array;
>
> void main () {
> Array!string a;
> struct Layout { string name; int value; double other; }
>
> a.insert(Layout);
> auto record =  uFile.byLineCopy().joiner("\n").csvReader!(Tuple!a[0]))
> foreach (record; records)
> {
>     writeln(record.name);
>     writeln(record.value);
>     writeln(record.other);
> }
>
> From,
> Vino.B

Hi All,

 Was able to find on hot to store a struct in an array, but not able to use that array in csvReader

Program:
import std.algorithm: joiner;
import std.container.array;
import std.csv: csvReader;
import std.stdio: File, writeln;
import std.typecons: Tuple, tuple;

void main () {
auto fName = "C:\\Users\\bheev1\\Desktop\\Current\\Script\\Others\\Table1.csv";
auto uFile = File(fName, "r");
struct T1 { string Name; string Country; int Age; }
Array!T1 T1s;
foreach (record; uFile.byLineCopy().joiner("\n").csvReader!(Tuple!T1s))
writeln(record);
}

Error:
C:\D\dmd2\windows\bin\..\..\src\phobos\std\typecons.d(523): Error: template instance parseSpecs!(T1s) cannot use local 'T1s' as parameter to non-global template
 parseSpecs(Specs...)
C:\D\dmd2\windows\bin\..\..\src\phobos\std\typecons.d(635): Error: CTFE failed because of previous errors in injectNamedFields
ArrayStruct.d(12): Error: template instance ArrayStruct.main.Tuple!(T1s) error instantiating
Failed: ["dmd", "-v", "-o-", "ArrayStruct.d", "-I."]

From,
Vino.B

On Tuesday, 9 January 2018 at 13:49:41 UTC, Vino wrote:
> Hi All,
>
>  It is possible to store struct in a array ans use the same in csvReader

Sure, you can just pass the type of your struct to csvReader:

struct Layout { string name; int value; double other; }

auto readArrayOfStructs(string fname) {
    Array!Layout res;
    foreach(record; fname.readText.csvReader!Layout('\t')) {
        res ~= record;
    }
    return res;
}

On Tuesday, 9 January 2018 at 17:00:05 UTC, thedeemon wrote:
> On Tuesday, 9 January 2018 at 13:49:41 UTC, Vino wrote:
>> Hi All,
>>
>>  It is possible to store struct in a array ans use the same in csvReader
>
> Sure, you can just pass the type of your struct to csvReader:
>
> struct Layout { string name; int value; double other; }
>
> auto readArrayOfStructs(string fname) {
>     Array!Layout res;
>     foreach(record; fname.readText.csvReader!Layout('\t')) {
>         res ~= record;
>     }
>     return res;
> }

Hi Deemon,

  Thank you, and sorry for the confusion, the requirement is as below

auto reader(T) (Array!T T1s, T fname) {
auto uFile = File(fName, "r");
foreach (record; uFile.byLineCopy().joiner("\n").csvReader!(Tuple!T1s)) // receive the type and fetch the record
writeln(record);
}

void main () {
auto fName = "C:\\Users\\bheev1\\Desktop\\Current\\Script\\Others\\Table1.csv";
struct T1 { string Name; string Country; int Age; }
Array!T1 T1s;
reader(fName, T1s); // pass the array Type as a function parameter
}


From,
Vino.B

On Tuesday, 9 January 2018 at 17:41:10 UTC, Vino wrote:
> On Tuesday, 9 January 2018 at 17:00:05 UTC, thedeemon wrote:
>> On Tuesday, 9 January 2018 at 13:49:41 UTC, Vino wrote:
>>> Hi All,
>>>
>>>  It is possible to store struct in a array ans use the same in csvReader
>>
>> Sure, you can just pass the type of your struct to csvReader:
>>
>> struct Layout { string name; int value; double other; }
>>
>> auto readArrayOfStructs(string fname) {
>>     Array!Layout res;
>>     foreach(record; fname.readText.csvReader!Layout('\t')) {
>>         res ~= record;
>>     }
>>     return res;
>> }
>
> Hi Deemon,
>
>   Thank you, and sorry for the confusion, the requirement is as below
>
> auto reader(T) (Array!T T1s, T fname) {
> auto uFile = File(fName, "r");
> foreach (record; uFile.byLineCopy().joiner("\n").csvReader!(Tuple!T1s)) // receive the type and fetch the record
> writeln(record);
> }
>
> void main () {
> auto fName = "C:\\Users\\bheev1\\Desktop\\Current\\Script\\Others\\Table1.csv";
> struct T1 { string Name; string Country; int Age; }
> Array!T1 T1s;
> reader(fName, T1s); // pass the array Type as a function parameter
> }
>
>
> From,
> Vino.B

Details

For example let say we have 3 struct
auto read(T) (T Filename, T ArrayType) {
T ArrayType res;
foreach (record; Filename.byLineCopy().joiner("\n").csvReader!(T)(Tuple!ArrayType))
foreach(i, T; ColumnTypes) { res[i].insert(record[i]); }
	}
	return res;
}

void main () {

struct S1 { }
struct S2 { }
struct S3 { }

Get user input(UI)
if(UI == S1) {
Array!S1 T1;
writeln(read(File1, Array Type));
}

From,
Vino.B

On Tuesday, 9 January 2018 at 18:09:58 UTC, Vino wrote:
>>>>  It is possible to store struct in a array ans use the same in csvReader
>>>
>>> Sure, you can just pass the type of your struct to csvReader:

>> Array!T1 T1s;
>> reader(fName, T1s); // pass the array Type as a function parameter

First you write a template function that takes an array of some generic type and fills it with records from CSV file:

void readData(DataType)(string fname, ref Array!DataType arr) {
    foreach (record; fname.readText.csvReader!DataType('\t')) {
        arr ~= record;
    }
}

Then you can use it in your main program with different types:

struct S1 { string name; string value; int other; }
struct S2 { int a; string b; }

void main () {
    ...
    if (someCondition) {
        Array!S1 arr1;
        readData("data1.csv", arr1);
    } else {
        Array!S2 arr2;
        readData("data2.csv", arr2);
    }
}

A little advice. Kindly pause and spend an evening reading this book:
http://ddili.org/ders/d.en/

Currently your code pieces look like a soup produced by someone who still confuses variables and types, and lacks basic programming skills. Read the book, don't rush with writing broken code.

On Tuesday, 9 January 2018 at 19:05:48 UTC, thedeemon wrote:
> On Tuesday, 9 January 2018 at 18:09:58 UTC, Vino wrote:
>>>>>  It is possible to store struct in a array ans use the same in csvReader
>>>>
>>>> Sure, you can just pass the type of your struct to csvReader:
>
>>> Array!T1 T1s;
>>> reader(fName, T1s); // pass the array Type as a function parameter
>
> First you write a template function that takes an array of some generic type and fills it with records from CSV file:
>
> void readData(DataType)(string fname, ref Array!DataType arr) {
>     foreach (record; fname.readText.csvReader!DataType('\t')) {
>         arr ~= record;
>     }
> }
>
> Then you can use it in your main program with different types:
>
> struct S1 { string name; string value; int other; }
> struct S2 { int a; string b; }
>
> void main () {
>     ...
>     if (someCondition) {
>         Array!S1 arr1;
>         readData("data1.csv", arr1);
>     } else {
>         Array!S2 arr2;
>         readData("data2.csv", arr2);
>     }
> }
>
> A little advice. Kindly pause and spend an evening reading this book:
> http://ddili.org/ders/d.en/
>
> Currently your code pieces look like a soup produced by someone who still confuses variables and types, and lacks basic programming skills. Read the book, don't rush with writing broken code.

Hi Deemon,

 I agree that my code is broken code and I am a Newbie in the world of programming, the confusion begin when i started writing the second module, and now i was able to find the issue, and the real requirement. The requirement is as below.

Program: The below program works.
auto reader(MyStruct) (File fname, auto ref MyStruct st) {
alias ColumnTypes = AliasSeq!(MyStruct);
foreach (record; fname.byLineCopy().joiner("\n").csvReader!(Tuple!ColumnTypes)(null)) {
writeln(record[0], record[1], record[2]);
}

void main () {
auto fname = File("C:\\Users\\bheev1\\Desktop\\Current\\Script\\Others\\Table2.csv");
auto Table = baseName(stripExtension(fname));
struct S1 { string Name; string Country; int Age; }
S1 Table1s;
reader(File(fname), join([Table, "1s"]));
}

The requirement is as below
The function reader should store the data in column wise Array and return the same.

Array!<Type has to be taken from ColumnTypes < Name of the array has to be taken from the header data as the CSV file has header Name, Country, Age using records.header)
e.g
Array!string Name; (records.header[0]);
Array!string Country;(records.header[1]);
Array!string Age;(records.header[2]);

and return the above arrays

From,
Vino.B