k-nucleotide Node.js #8 program

/* The Computer Language Benchmarks Game
   https://salsa.debian.org/benchmarksgame-team/benchmarksgame/
   
   Naive transliteration from bearophile's program
   contributed by Isaac Gouy   
*/

const rl = require("node:readline");

async function seq_lines() {
    const stdin = rl.createInterface({
        input: process.stdin,
    });    
    const lines = [];
    let started = false;    
    for await (const line of stdin) {      
        if (started) {
            if (line.startsWith(">")) break;       
            lines.push(line);
        } else {
            started = line.startsWith(">THREE");        
        }
    }  
    return lines;
}

function base_counts(bases, seq) { 
    counts = new Map();
    size = seq.length + 1 - bases;     
    for (let i = 0; i < size; i++) {   
        const nucleo = seq.substring(i,i+bases); 
        var v; if (v = counts.get(nucleo))        
            counts.set(nucleo,v+1); 
        else
            counts.set(nucleo,1);          
    }
    return counts;    
}

function sorted_freq(bases, seq) {
    size = seq.length + 1 - bases;  
    counts = base_counts(bases, seq); 
    return Array.from(counts)
        .sort((a, b) => b[1] - a[1]) 
        .map((a) => [a[0], 100.0 * a[1] / size]);     
}   

function specific_count(code, seq) {  
    counts = base_counts(code.length,seq);
    return counts.get(code) ? counts.get(code) : 0;        
}   

function write_freq(a) {  
    console.log(`${a[0]} ${a[1].toFixed(3)}`);        
}  

function main(n) {
    seq_lines().then(a => {
        const seq = a.map((s) => s.toUpperCase()).join("");
        
        for (const base of [1,2]) {  
            sorted_freq(base,seq).forEach(write_freq);     
            console.log();             
        }
        
        for (const code of ["GGT", "GGTA", "GGTATT",
                "GGTATTTTAATT", "GGTATTTTAATTTATAGT"]) {  
            console.log(`${specific_count(code,seq)}\t${code}`);           
        }   
               
    } );          
}            

main(+process.argv[2] || 0)
    

NOTES:
64-bit Ubuntu quad core
v23.0.0


 Wed, 11 Dec 2024 01:04:14 GMT

MAKE:
cp -L knucleotide.node-8.node knucleotide.js

0.07s to complete and log all make actions

COMMAND LINE:
 /opt/src/node-v23.0.0/bin/node knucleotide.js 0 < knucleotide-input25000000.txt

PROGRAM OUTPUT:
A 30.295
T 30.151
C 19.800
G 19.754

AA 9.177
TA 9.132
AT 9.131
TT 9.091
CA 6.002
AC 6.001
AG 5.987
GA 5.984
CT 5.971
TC 5.971
GT 5.957
TG 5.956
CC 3.917
GC 3.911
CG 3.909
GG 3.902

1471758	GGT
446535	GGTA
47336	GGTATT
893	GGTATTTTAATT
893	GGTATTTTAATTTATAGT