simple code generator

Last semester I was taking a mandatory "Programming 101" course, aka. drawing stairs made out of stars and watching my classmates struggle with basic tasks, the course - a time truly well spent. Even though the course problems weren’t too enlightening, the silliness of one of the tasks’ requirements gave me a chance to write a simple code generator.

Problem

Without using an associative table (they weren’t covered in class), write a program that encodes a message using morse code. The characters should map as follow (yes, a picture; who needs copy-paste anyway?):

Implementation

First, I looked online for the table in a text format, downloaded it and, using a vim macro, formatted it so that each line would contain one of the ASCII symbols and its Morse representation separated by a space. Since I wanted to use envsubst, I created a file like so:

    else if (morse_representation == "${CASE}") {
        return '${VALUE}'
    }

Then, I wrote a script that reads each line from the ‘translation file’, and places the Morse representation inside the if’s condition and the ASCII symbol next to the return statement:

    #!/usr/bin/env sh
    while read line; do
        line=($line)
        export CASE=${line[1]}
        export VALUE=${line[0]}
        truncate -s-1 from_morse_code.cc
        envsubst < switch_case.cc >> from_morse_code.cc
    done < morse_code.txt

I ran it, ran it again with the values of the CASE and VALUE variables switched as to generate the other way translation, removed the unneeded elses at the bottom, copy-pasted the big if chains into the file where I would write the wrapper code... and voila! An hour of time was just saved (if you’re not counting the hour it took me to write this lol)!