Class: ShenRuby::Shen

Inherits:
Klam::Environment
  • Object
show all
Defined in:
lib/shen_ruby/shen.rb

Overview

Instances of the ShenRuby::Shen class provide a Shen environment running within a Klam environment. This class is essentially a loader Shen’s KLambda sources and the ShenRuby extensions.

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize ⇒ Shen

Returns a new instance of Shen.



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# File 'lib/shen_ruby/shen.rb', line 6

def initialize
  super

  # Set the global variables
  set("*language*".to_sym, "Ruby")
  set("*implementation*".to_sym, "#{::RUBY_ENGINE} #{::RUBY_VERSION}")
  set("*release*".to_sym, ::RUBY_VERSION)
  set("*port*".to_sym, ::ShenRuby::VERSION)
  set("*porters*".to_sym, "Greg Spurrier")
  set("*home-directory*".to_sym, ::Dir.pwd)
  set("*stinput*".to_sym, ::STDIN)
  set("*stoutput*".to_sym, ::STDOUT)

  # Load the K Lambda files
  kl_root = ::File.expand_path('../../../shen/release/klambda', __FILE__)
  %w(toplevel core sys).each do |kl_filename|
    ::ShenRuby::Shen.load_file(self, ::File.join(kl_root, kl_filename + ".kl"))
  end

  # Overrides
  class << self
    # Give a way to bail out
    def quit
      ::Kernel.exit(0)
    end

    # Add a way to evaluate strings, intended for use with Ruby interop.
    # Returns the result of the last expression evaluated.
    def eval_string(s)
      forms = __send__(:"read-from-string", s)
      result = nil
      while forms
        result = eval(head(forms))
        forms = tail(forms)
      end
      result
    end
    alias_method :"eval-string", :eval_string

    # The performance of `element?` is critical
    def element?(x, l)
      while l
        return true if l.hd == x
        l = l.tl
      end
      return false
    rescue => e
      __send(:"shen.sys-error", :element?)
    end

    def vector(n)
      v = ::Klam::Absvector.new(n + 1, :"shen.fail!")
      v[0] = n
      v
    end
  end

  # Load the rest of the K Lambda files
  %w(sequent yacc
     reader prolog track load writer
     macros declarations types t-star
    ).each do |kl_filename|
    ::ShenRuby::Shen.load_file(self, ::File.join(kl_root, kl_filename + ".kl"))
  end

  # Give type signatures to the new functions added above
  declare :quit, cons(:"-->", cons(:unit, nil))
  declare :eval_string, cons(:string, cons(:"-->", cons(:unit, nil)))
  declare :"eval-string", cons(:string, cons(:"-->", cons(:unit, nil)))

  systemf :"rb-const"
  systemf :"rb-send"
  systemf :"rb-send-block"

  old_hush = value(:"*hush*")
  set :"*hush*", true
  load ::File.expand_path('../rb.shen', __FILE__)
  load ::File.expand_path('../shen_ruby.shen', __FILE__)
  set :"*hush*", old_hush
end

Class Method Details

.load_file(env, path) ⇒ Object 



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# File 'lib/shen_ruby/shen.rb', line 88

def load_file(env, path)
  ::File.open(path, 'r') do |file|
    reader = ::Klam::Reader.new(file)
    while form = reader.next
      env.__send__(:"eval-kl", form)
    end
  end
end