Web Development with ReasonML

Putting Modules to Work

Now that we have our records and modules set up, we’re going to write a command-line NodeJS program in ReasonML that reads a file of shirt orders, with each order represented as a line of comma-separated values. The program will get the name of the file to read from the command line argument and output a list of sales by size, color, pattern, collar, and cuff type. Here’s what it looks like when it grows up:

$ node src/Stats.bs.js orders.csv
Color Quantity
white 118
blue 114
red 73
...

Here are the first few lines of a sample input file, with the first line being a header line:

Quantity,Size,Color,Pattern,Collar,Sleeve,Cuff
6,L,white,solid,straight,long,button
5,L,blue,pinstripe,straight,xlong,button
5,M,red,check,spread,long,button ...