yield

A program showing a pattern in Pony to transform for/while loops (which could run infinitely) into tail-recursive behavior calls -- the advantage of this beyond avoiding a non-yielding actor is that garbage collection occurs between behaviors.

How to Compile

With a minimal Pony installation, in the same directory as this README file run ponyc. You should see content building the necessary packages, which ends with:

...
Generating
 Reachability
 Selector painting
 Data prototypes
 Data types
 Function prototypes
 Functions
 Descriptors
Optimising
Writing ./yield.o
Linking ./yield

How to Run

Once yield has been compiled, in the same directory as this README file run ./yield. You should see a message showing the "infinite" actor has started, followed by the result of the kill command.

$ ./yield
Beep boop!
Ugah!

This program has multiple "sub-programs" in it which you can see with --help.

$ ./yield --help
usage: yield [<options>] [<args> ...]

Demonstrate use of the yield behaviour when writing tail recursive
behaviours in pony.

By Default, the actor will run quiet and interruptibly.

Options:
   -b, --bench=0         Run an instrumented behaviour to guesstimate overhead of non/interruptive.
   -d, --debug=false     Run in debug mode with verbose output.
   -h, --help=false
   -l, --lonely=false    Run a non-interruptible behaviour with logic that runs forever.
   -p, --punk=false      Run a punctuated stream demonstration.

Try running each of these program, but beware --lonely will run forever so you will need to externally kill it.

Program Modifications

Modify the program to make each of the above options into (leaf) subcommands by making the existing "yield" a parent command. debug should be the only subcommand which takes an argument.

$ ./yield bench --perf=10
...

$ ./yield debug
...

$ ./yield lonely
...

$ ./yield punk
...