Shen-js

Running in Node.js

The current Node.js port support compiling, executing source files as well as REPL.

To use it, navigate to this repository in your console, then do:

> npm install -g
> shen-js --help

  Usage: shen-js [options] <file ...>

  Options:

    -h, --help         output usage information
    -V, --version      output the version number
    -c, --compile      Compile to JavaScript and save as .js files
    -i, --interactive  Run an interactive Shen REPL
    -p, --print        Print compiled JavaScript instead of writing to file

shen-js [filename] will execute the specified source file. Executing shen-js without args will drop you to the REPL

Running console REPL

Type in your terminal (choose a line depending on your js interpreter):

d8 -e 'load("shen.js"); Shen.console_repl()'
js -e 'load("shen.js"); Shen.console_repl()'

Running provided REPL in browser

Put shen.html, shen.css, shen.js, shen-repl-html.js, fileio-html5,js into a directory of your choice. Then open shen.html in your browser. It's been tested in Firefox and WebKit-based browsers (Chrome and Surf).

Working with files is a bit clumsy. It requires manual interventions and has limited filesize. Shen-js maintains list of files it has access to directly on a page. To add local files into it use button under Filesystem title. To download written file to your local drive press on that file in a list. Currently only Chrome supports naming such files. On firefox specify correct name manually.

JS integration

To define a Shen function from javascript use Shen.mkfunction.

Shen.mkfunction takes three arguments:

name of a function
number of arguments
function

function takes a vector as an argument and must check its length. If length is less than expected it must return function object which is a four element vector with elements:

1. `Shen.type_func`,
2. function object,
3. number of arguments,
4. closure vector.

Example:

Shen.mkfunction("plus", 2, function f(args) {
  if (args.length < 2) return [Shen.type_func, f, 2, args]
  return args[0] + args[1]
})

To load javascript file from Shen use shenjs.load function. To call Shen function (some-func Arg1 Arg2) from javascript use Shen.call_by_name("some-func", [Arg1, Arg2]).

Making your own REPL and I/O

To write your own Shen-js REPL and I/O you have to pass your io class to Shen.init. Your class must have the following members:

init — called from Shen.init. Initializes IO class instance. It also initializes *stinput* and *stoutput* streams.
puts — prints a line. It must not implicitely add a trailing newline.
gets — reads a line from repl.
open — is a function(type, name, direction) and is a direct mapping of shen's open function.

Stream type

Objects (stream in) or a (stream out) are represented in Shen-js as following.

(stream in) — [Shen.type_stream_in, read_byte(), close()]
(stream out) — [Shen.type_stream_out, write_byte(byte), close()]
read_byte function returns numeric value of a next byte from a stream or -1 as end of file marker.
write_byte function writes a byte to a stream. byte is a number.
close closes a stream.

You can look at Shen.console_io object and Shen.console_repl function as a references.

Current implementation sets *stinput* as in/out stream as a workaround of Shen using *stinput* for output.

xkxx / shen-js