partialruby - Ruby partial interpreter written in pure ruby

What I trying to say with “partial” ? Well, the ruby interpreter is composed by a few main conceptual “components”: parser, api, VM and execution environment. A partial interpreter will be a library implementing only one or even only part of one of these basic components. In this case, partialruby only implements part of the VM (e.g. partialruby DOESN’T implement a GC), use the excenllent ruby_parser gem (github.com/seattlerb/ruby_parser) to parse ruby code and use the real interpreter to the rest (api, environment, etc…).

Goals:

Implement a alternative VM which export services that is not exported by the original VM without implementing a entire ruby interpreter or fork an existing ruby interpreter

- Control of execution flow via hooking for sandboxing (see evalhook and shikashi projects) - Fast DSL (over ruby, and faster than ruby itself!)

Proof of Concept of interpreter and partial interpreter development

- Hyper-portability: microruby - Search for a faster ruby

Installation

Gem Installation (pending)

sudo gem install partialruby

Download the last version of the gem from github.com/tario/partialruby/downloads
Install the gem with the following;

sudo gem install partialruby-X.X.X.gem.

Documentation (pending)

Full API documentation can be found on: tario.github.com/partialruby/doc/

Usage (pending)

Basically, partialruby export two APIs:

A alernative eval function with context. Example:

require “partialruby”

context = PartialRuby::Context.new context.eval(‘print “hello worldn”’)

require "partialruby"

PartialRuby.eval('print "hello world\n"')

A flexible node handling. Example

require “partialruby”

class MyPartialRubyContext < PartialRuby::Context

def ruby_emul_call(tree)
    object_tree = tree[1]
    method_name = tree[2]

    arglist = tree[3]

    argsstr = arglist[1..-1].
          map{|subtree| "(" +  emul(subtree, frame) + ")" }.
          join(",")

    if (object_tree)
      "((#{emul(object_tree)}).#{method_name}(#{argsstr})"
    else
      if arglist.count == 0
      "#{method_name}(#{argsstr})"
      else
      "#{method_name}"
      end
    end

end

end

context = MyPartialRubyContext.new context.eval(‘print “hello worldn”’)