Adding some documentation.

README.md

@@ -0,0 +1,7 @@
+# mkz_aoc
+
+## Modules
+
+- file: Open files & prepare inputs
+- parse: Parse contents (moslty from Strings to Vec/integers
+)

src/file.rs

@@ -1,7 +1,18 @@
+//! This module proposes reading file helper functions.
+
 use std::fs;
 
 use crate::parse::string_to_numbers;
 
+/// Read a file & return its contents in a Vec<String> structure
+///
+/// ```
+/// use mkz_aoc::file;
+///
+/// fn main() {
+///    let lines = file ::read_to_numbers("input.txt");
+/// }
+/// ```
 pub fn read_to_lines(_filename: &str) -> Result<Vec<String>, String> {
     let _contents = fs::read_to_string(_filename);
     if let Err(v) = _contents {
@@ -13,6 +24,17 @@ pub fn read_to_lines(_filename: &str) -> Result<Vec<String>, String> {
     Ok(lines)
 }
 
+/// Read a file & return its contents in a Vec<i128> structure 
+pub fn read_to_numbers(_filename: &str) -> Result<Vec<i128>, String> {
+    let _lines = read_to_lines(_filename);
+    if let Err(v) = _lines {
+        return Err(v);
+    }
+
+    Ok(_lines.unwrap().iter().map(|x| x.parse::<i128>().unwrap()).collect::<Vec<i128>>())
+}
+
+/// Read a file & return its first line in a String
 pub fn read_to_string(_filename: &str) -> Result<String, String> {
     let _lines = read_to_lines(_filename);
 
@@ -26,6 +48,7 @@ pub fn read_to_string(_filename: &str) -> Result<String, String> {
     }
 }
 
+/// Read a file for a matrix & return it in a Vec<Vec<i128>> data structure.
 pub fn read_to_matrix(_filename: &str) -> Result<Vec<Vec<i128>>, String> {
     let _lines = read_to_lines(_filename);
 

src/lib.rs

@@ -1,2 +1,5 @@
+#![deny(missing_docs)]
+//! This create implements some useful helper functions to solve Advent of Code problems.
+
 pub mod file;
 pub mod parse;

src/parse.rs

@@ -1,7 +1,11 @@
+//! Parsing helper functions
+
+/// Transform a String with only digits to a number array.
 pub fn string_to_usize_vec(input: String) -> Vec<usize> {
     input.chars().map(|x| x.to_digit(10).unwrap() as usize).collect()
 }
 
+/// Transform a string to a i128 array.
 pub fn string_to_numbers(input: String) -> Vec<i128> {
     input
         .split_whitespace()