#Nock.js
This is an implementation of Nock in JavaScript. If you don't know what Nock is, go urbit.org. Read some documentation. Then request a destroyer, run :chat, and then say hello to everyone. Your humble author might well be online (~nosryl-tarpem). Let him know if you find any bugs.
This implementation is for pedagogic purposes, i.e. to let people play around with Nock and see how it works. It's not intended to power a browser-based Arvo implementation, although if someone wants to take this and make that happen, that would be pretty awesome.
##Usage
Despite being JavaScript, this project has no web-based interface. Instead, it runs using node.js. Run repl.js like so:
node repl.js
nock.js features a parser, so enter nock pseudocode at the prompt and it will perform its reductions until it either comes up with a solution or crashes. Try entering some samples from the Urbit documentation and following along.
There's also a one-line command evaluator, called oneliner.js, which you can run like so:
node oneliner.js *[42 0 1]
This will evaluate the given command and then exit, which is useful if you want to redirect stdout. And really who doesn't?
Brian Zick has written a web-based REPL, which you can check out here.
##Strict Mode
The interpreter has two modes. Strict mode (the default) hews as closely as possible to the Nock spec. You can disable strict mode and use pre-reduced functions, which speeds things up quite a bit. Disable strict mode by entering "strict=off" at the command prompt.
Here are the pre-reduced versions of the commands, for your reference. Most of these are described in detail in Chapter 3 of the documentation:
Nock 6:
32r :: *[a 6 b c d] *[a *[[c d] [0 *[[2 3] [0 ++*[a b]]]]]]
Nock 7:
33r :: *[a 7 b c] *[*[a b] c]
Nock 8:
34r :: *[a 8 b c] *[[*[a b] a] c]
Nock 9:
35r :: *[a 9 b c] *[*[a c] *[*[a c] 0 b]]
Nock 10:
36r :: *[a 10 [b c] d] *[*[[*[a c] a] 0 3] d]
37r :: *[a 10 b c] *[a c]