Here is a sample repo to demonstrate how to use a simple Go program that reads from standard input a domain name in unicode form, and outputs the IDN ASCII version of the name.

The source code can be found in the goidn directory.

There is also a lib directory that contains a GoIDN library in Perl5 that uses IPC::Open2 to spawn the program passed as a binary and attaches two (2) filehandles, one for reading, one for writing.

A method called to_ascii(domain_name) writes to the write filehandle, effectively passing the request to the Go program which returns instantly and through the read filehandle.

A simple benchmark returns:

timethis 1000000: 11 wallclock secs ( 4.24 usr +  2.86 sys =  7.10 CPU) @ 140845.07/s (n=1000000)

So about ~14.1k calls a second on my Macbook Pro