Choosing a Language for Bioinformatics
ducktape.blot.im
ducktape.blot.im
I see in your post that you are about to look into Nim/C interop; have a look at nimterop[1]. It has been immensely useful to me for wrapping Nim libraries around C code exported from Matlab and to talk with C API for SystemVerilog.
Finally, you blog post shows a snippet of Python code, but also show to the world how the Nim code looks [I know that you are sharing the link to the git repo containing the Nim code, but still] :)
$ awk \
'BEGIN{for (i=0; i<2000000; i++){print "abcdef\tghijk\tlmnop\tqrstuv\twxyz1234\tABCDEF\tHIJK\tLMNOP\tQRSTUV\tWXYZ123"}}' \
> big.tsv
$ cat big.tsv |sort|uniq -c
2000000 abcdef ghijk lmnop qrstuv wxyz1234 ABCDEF HIJK LMNOP QRSTUV WXYZ123
You can first sort all the lines, and count them.
The first column is now the number of instances of that line.The idea is that if 2 lines are identical, the number of "count++" emitted will be exactly the same.
I took your gawk code, but I am starting the for loop at 2 instead of 1, and I removed the -F'\t' option.
$ time cat big.tsv |sort | uniq -c \
| gawk '{for (i=2; i <= NF; i++) {if (index(tolower(substr($i, 1, 3)), "bc") != 0) {count += $1}}}END{print count}'
4000000
real 0m0.724s
user 0m0.605s
sys 0m0.322s
Edit: added backslashes to split lines.