Added some comments

src/lib.rs

@@ -1,3 +1,10 @@
+// Copyright Ravi Shah 2021
+// You should've got the GPL v3.0 with this software
+// If ya didn't, it's available here:
+// https://www.gnu.org/licenses/gpl-3.0.en.html
+
+// Imports
+
 mod utils;
 
 use wasm_bindgen::prelude::*;
@@ -15,6 +22,8 @@ pub fn transcription(dna: String) -> String {
     let mut transcribed_vec: Vec<char> = Vec::new();
     for i in char_vec {
 
+        // Basically converts DNA strand to mRNA
+
         match i {
             'A' => transcribed_vec.push('U'),
             'T' => transcribed_vec.push('A'),
@@ -26,25 +35,30 @@ pub fn transcription(dna: String) -> String {
         }
     }
 
+    // Collect transcribed mRNA into a String
     let transcribed_string: String = transcribed_vec.into_iter().collect();
     return transcribed_string;
 }
 
 pub fn find_start(messenger_rna: String) -> String {
     let start_codon = "AUG";
+    // Find index of start codon
     let start_index = messenger_rna.find(start_codon).unwrap();
+    // Remove anything before start codon
     let inter_rna: String = messenger_rna.chars().skip(start_index).collect();
     return inter_rna;
 }
 
 pub fn break_into_codons(inter_rna: String) -> Vec<String> {
     let sub_len = 3;
+    // Split into codons (chunks of 3 bases each)
     let subs = inter_rna.as_bytes()
         .chunks(sub_len)
         .map(str::from_utf8)
         .collect::<Result<Vec<&str>, _>>()
         .unwrap();
 
+    // Combine into a vector
     let mut string_vec: Vec<String> = Vec::new();
     for i in &subs {
         string_vec.push(i.to_string());
@@ -58,6 +72,7 @@ pub fn find_stop(inter_codons: &[String]) -> usize {
     let mut stop_index_2: usize = usize::MAX;
     let mut stop_index_3: usize = usize::MAX;
 
+    // Find position of any stop codons
     if inter_codons.iter().any(|i| i == "UAA") {
         stop_index_1 = inter_codons.iter().position(|r| r == "UAA").unwrap();
     }
@@ -76,6 +91,7 @@ pub fn find_stop(inter_codons: &[String]) -> usize {
 pub fn find_first(stop_index_1: usize, stop_index_2: usize, stop_index_3: usize) -> usize {
     let mut stop_index: usize = 1;
 
+    // Find which stop codon actually occured first
     if stop_index_1 < stop_index_2 {
         if stop_index_1 < stop_index_3{
             println!("UAA stop codon found!");
@@ -105,6 +121,7 @@ pub fn find_first(stop_index_1: usize, stop_index_2: usize, stop_index_3: usize)
 pub fn translation(inter_codons: Vec<String>) -> Vec<String> {
     let mut amino_acids_list: Vec<String> = Vec::new();
 
+    // Matching codons to amino acids
     for i in inter_codons {
         match i.as_str() {
              "GUU" | "GUC" | "GUA" | "GUG" => amino_acids_list.push("Valine".to_string()),
@@ -142,30 +159,32 @@ pub fn translation(inter_codons: Vec<String>) -> Vec<String> {
 pub fn main(mut strand: String) {
     println!("Enter the DNA strand to be transcribed and translated: ");
 
-    strand = strand.to_string().to_uppercase();
+    strand = strand.to_string().to_uppercase(); // Convert to uppercase
 
-    let messenger_rna = transcription(strand);
+    let messenger_rna = transcription(strand); // Transcribe strand
     println!("The transcribed strand is: {}", messenger_rna);
-    let inter_rna = find_start(messenger_rna);
+    let inter_rna = find_start(messenger_rna); // Find start codon
     println!("{}", inter_rna);
-    let mut inter_codons = break_into_codons(inter_rna);
-    let mut stop_index = find_stop(&inter_codons);
+    let mut inter_codons = break_into_codons(inter_rna); // Break into codons
+    let mut stop_index = find_stop(&inter_codons); // Find index of stop codon
     stop_index = stop_index + 1;
     println!("{}", stop_index);
-    inter_codons.truncate(stop_index);
-    let amino_acids_list = translation(inter_codons);
+    inter_codons.truncate(stop_index); // Truncate at stop index
+    let amino_acids_list = translation(inter_codons); // Translate to amino acids
 
     // Use `web_sys`'s global `window` function to get a handle on the global
     // window object.
     let window = web_sys::window().expect("no global `window` exists");
     let document = window.document().expect("should have a document on window");
-    let codons_div = document.get_element_by_id("codons").expect("codons div should exist");
+    let codons_div = document.get_element_by_id("codons").expect("codons div should exist"); // Get codons div
 
+    // Insert codons header into the DOM
     let val = document.create_element("h2").unwrap();
     val.set_text_content(Some("Codons:"));
     codons_div.append_with_node_1(&val).unwrap();
 
     print!("The translated amino acids are: ");
+    // Insert amino acids into the DOM
     for i in amino_acids_list {
         let val = document.create_element("p").unwrap();
         val.set_text_content(Some(&i));