grouping - How to make pairs from Range? -

i have got range mysqltablesrange. it's consist data like: aa_1 aa_3 aa_2 bb_2 bb_1 bb_3

i need create pairs like: aa_1 bb_1 aa_2 bb_2 aa_3 bb_3

std.algorithm have method group doing similar thing, not know how write in code. did:

mysqltablesrange.each!(a => a.split("_")[1].array.group.writeln);

but it's wrong, because group works array, not single element.

any ideas?

update: after testing - realised it's not 'group' want. chunkby. updated answer reflect that. https://dlang.org/phobos/std_algorithm_iteration.html#chunkby

you have tell chunkby how chunk data...

[1,2,3,4,5,6]     .sort!((a,b) => a%2 > b%2)        // separate odds n evens     .chunkby!((a,b) => a%2 == b%2);   // chunk them evens in 1 range, odds in another. 

that create 2 groups. 1 odd numbers, 1 evens.

in case looks you'd group them on text comes after '_' in each element.

"aa_1 aa_2 aa_3 bb_1 bb_2 bb_3 cc_1"     .split(" ")     .sort!((a,b) => a[$-1].to!int < b[$-1].to!int) // sort _1's together, _2s together. etc     .chunkby!((a,b) => a[$-1] == b[$-1]) // chunk them they're in they're own range     .each!writeln;   // print each range  $ rdmd test.d ["aa_1", "bb_1", "cc_1"] ["aa_2", "bb_2"] ["aa_3", "bb_3"] 

ideally you'd index of _ , compare after that...