Day 2

fOOrth.gemspec

@@ -26,6 +26,7 @@ Gem::Specification.new do |s|
   s.files += Dir['tests/*.rb']
 
   s.files += ['rakefile.rb',
+              'sire.rb',
               'license.txt',
               'readme.txt',
               'reek.txt']

lib/fOOrth.rb

@@ -2,6 +2,8 @@
 
 # The fOOrth Language System implemented via a Ruby gem.
 
+require_relative 'fOOrth/exceptions'
+require_relative 'fOORth/core'
 require_relative 'fOOrth/interpreter'
 require_relative 'fOOrth/compiler'
 require_relative 'fOOrth/main'
@@ -13,7 +15,7 @@ module XfOOrth
   #The version of this module.
   #<br>Returns
   #* A version string; <major>.<minor>.<step>
-  def version
+  def self.version
     "00.06.00"
   end
 
@@ -25,7 +27,7 @@ module XfOOrth
     #Create an new instance of a fOOrth virtual machine
     #<br>Parameters:
     #* name - An optional string that describes this virtual machine instance.
-    def initialize(name='----')
+    def initialize(name='-')
       @name = name
 
       #Bring the major sub-systems to a known state.

lib/fOOrth/compiler.rb

@@ -4,6 +4,7 @@
 module XfOOrth
 
   class VirtualMachine
+    attr_accessor :debug
   end
 
 end

lib/fOOrth/exceptions.rb

@@ -0,0 +1,16 @@
+# coding: utf-8
+
+#* exceptions.rb - Exception classes for the fOOrth language interpreter.
+module XfOOrth
+  #The generalize exception used by all fOOrth specific exceptions.
+  class XfOOrthError < StandardError; end
+
+  #The exception raised to force the fOOrth language system to exit.
+  class ForceExit    < StandardError; end
+
+  #The exception raised to silently force the fOOrth language system to exit.
+  class SilentExit    < StandardError; end
+
+  #The exception raised to force the fOOrth language system to abort execution.
+  class ForceAbort   < StandardError; end
+end

lib/fOOrth/interpreter.rb

@@ -6,6 +6,17 @@ require_relative 'interpreter/data_stack'
 module XfOOrth
 
   class VirtualMachine
+
+    #The fOOrth control stack. This is mostly used to hold information
+    #relating to control structures during compile and interpretation.
+    attr_reader :ctrl_stack
+
+    #Reset the state of the fOOrth inner interpreter.
+    def interpreter_reset
+      @data_stack   = Array.new
+      @ctrl_stack   = Array.new
+      @start_time   = Time.now
+    end
   end
 
 end

lib/fOOrth/interpreter/data_stack.rb

@@ -2,8 +2,83 @@
 
 #* data_stack.rb - The fOOrth language system data stack.
 module XfOOrth
-
   class VirtualMachine
-  end
+    #The fOOrth data stack. This is the primary means used to hold data
+    #for processing.
+    attr_reader :data_stack
 
+    #Add an entry to the data stack.
+    #<br>Parameters:
+    #* datum - The data to be added to the data stack.
+    def push(datum)
+      @data_stack << datum
+    end
+
+    #Remove the "top" entry from the data stack.
+    #<br>Returns:
+    #* The "top" element of the data stack.
+    #<br>Note:
+    #* If the stack is empty this will raise a XfOOrthError exception.
+    def pop
+      unless @data_stack.length >= 1
+        fail XfOOrthError, "Data Stack Underflow: pop"
+      end
+
+      @data_stack.pop
+    end
+
+    #Remove multiple entries from the "top" of the data stack.
+    #<br>Parameters:
+    #* count - the number of elements to be returned.
+    #<br>Returns:
+    #* An array containing the "top" count elements of the data stack.
+    #<br>Note:
+    #* Raises a XfOOrthError exception if the stack has too few data.
+    def popm(count)
+      unless @data_stack.length >= count
+        fail XfOOrthError, "Data Stack Underflow: popm"
+      end
+
+      @data_stack.pop(count)
+    end
+
+    #Remove the "top" entry from the data stack as a boolean.
+    #<br>Returns:
+    #* The "top" element of the data stack as a boolean
+    #<br>Note:
+    #* If the stack is empty this will raise a XfOOrthError exception.
+    def pop?
+      pop.to_fOOrth_b
+    end
+
+    #Read an entry from the data stack without modify that stack.
+    #<br>Parameters:
+    #* index - The (optional) entry to be retrieved. 1 corresponds to the
+    #  "top" of the stack, 2 the next element, etc.
+    #  This parameter defaults to 1.
+    #<br>Returns:
+    #* The element specified from the data stack.
+    #<br>Note:
+    #* Attempting to access an element deeper than the number of elements
+    #  on the stack will fail with an XfOOrthError exception.
+    def peek(index=1)
+      unless @data_stack.length >= index
+        fail XfOOrthError, "Data Stack Underflow: Peek"
+      end
+      @data_stack[-index]
+    end
+
+    #Read an entry from the data stack as a boolean without modify that stack.
+    #<br>Parameters:
+    #* index - The (optional) entry to be retrieved. 1 corresponds to the "top"
+    #  of the stack, 2 the next element, etc. This parameter defaults to 1.
+    #<br>Returns:
+    #* The element specified from the data stack as a boolean.
+    #<br>Note:
+    #* Attempting to access an element deeper than the number of elements on
+    #  the stack will fail with an XfOOrthError exception.
+    def peek?(index=1)
+      peek(index).to_fOOrth_b
+    end
+  end
 end

lib/fOOrth/main.rb

@@ -5,35 +5,124 @@ require 'getoptlong'
 #* main.rb - The entry point for a stand-alone fOOrth session.
 module XfOOrth
 
-  class VirtualMachine
-    @library_loaded = false
+  @library_loaded = false
 
-    #Has the fOOrth run time library been loaded?
-    def library_loaded?
-      @library_loaded
-    end
+  #Has the fOOrth run time library been loaded?
+  def self.library_loaded?
+    @library_loaded
+  end
 
-    #The fOOrth run time library has been loaded!
-    def library_loaded
-      @library_loaded = true
-    end
+  #The fOOrth run time library has been loaded!
+  def self.library_loaded
+    @library_loaded = true
+  end
 
-    #The starting point for an interactive fOOrth programming session.
-    #This method only returns when the session is closed.
-    #<br>To launch a fOOrth session, simply use:
-    # XfOOrth::VirtualMachine.new.main
-    def main
+  #The starting point for an interactive fOOrth programming session.
+  #This method only returns when the session is closed.
+  #<br>Returns:
+  #* The virtual machine used to run the session.
+  #<br>To launch a fOOrth interactive session, simply use:
+  # XfOOrth::main
+  def self.main
+    vm = VirtualMachine.new('main')
+
+    begin
+
+      loop do
+        begin
+          running ||= start_up(vm)
+          vm.eceute_console
+
+        rescue ForceAbort => forced_abort
+          vm.display_abort(forced_abort)
+          break unless running
+        end
+      end
+
+    rescue Interrupt
+      puts "\nProgram interrupted. Exiting fOOrth."
+
+    rescue ForceExit
+      puts "\nQuit command received. Exiting fOOrth."
+
+    rescue SilentExit
+      puts
+
+    rescue Exception => err
+      puts "\n#{err.class.to_s.gsub(/.*::/, '')} detected: #{err}"
+      puts err.backtrace
 
     end
 
-    #Process the command line arguments. A string is returned containing
-    #fOOrth commands to be executed after the dictionary is loaded.
-    #<br>Returns
-    #A string of fOOrth commands to be executed after the dictionary is loaded.
-    def process_command_line_options
+    vm
+  end
 
+  #Perform one time start-up actions.
+  def self.start_up(vm)
+    announcement
+    vm.debug = false
+    vm.exec_str.process_command_line_options
+    true
+  end
+
+  #Display the start-up messages for the interactive session.
+  def self.announcement
+    puts "fOOrth Reference Implementation Version: #{XfOOrth.version}"
+    fmt = '%Y-%m-%d at %I:%M%P'
+    puts "Session began on date: #{Time.now.strftime(fmt)}"
+  end
+
+  #Process the command line arguments. A string is returned containing
+  #fOOrth commands to be executed after the dictionary is loaded.
+  #<br>Returns
+  #A string of fOOrth commands to be executed after the dictionary is loaded.
+  def self.process_command_line_options
+    begin
+      defer, found = "", false
+
+      opts = GetoptLong.new(
+        [ "--help",  "-h", "-?", GetoptLong::NO_ARGUMENT ],
+        [ "--load",  "-l",       GetoptLong::REQUIRED_ARGUMENT ],
+        [ "--debug", "-d",       GetoptLong::NO_ARGUMENT ],
+        [ "--quit",  "-q",       GetoptLong::NO_ARGUMENT ],
+        [ "--words", "-w",       GetoptLong::NO_ARGUMENT ])
+
+      # Translate the parsed options into fOOrth.
+      opts.each do |opt, arg|
+        unless found
+          puts; found = true
+        end
+
+        case opt
+        when "--debug"
+          @debug = true
+        when "--load"
+          defer << "load\"#{arg}\" "
+        when "--quit"
+          defer << ")quit "
+        when "--words"
+          defer << ")words "
+        else
+          fail SilentExit
+        end
+      end
+
+      puts if found
+
+    rescue Exception
+      puts
+      puts "fOOrth available options:"
+      puts
+      puts "--help  -h  -?          Display this message and exit."
+      puts "--load  -l <filename>   Load the specified fOOrth source file."
+      puts "--debug -d              Default to debug ON."
+      puts "--quit  -q              Quit after processing the command line."
+      puts "--words -w              List the current vocabulary."
+      puts
+      raise SilentExit
     end
 
+    defer
   end
 
 end

rakefile.rb

@@ -4,21 +4,26 @@
 require 'rake/testtask'
 require 'rdoc/task'
 
+#Generate internal documentation with rdoc.
 RDoc::Task.new do |rdoc|
   rdoc.rdoc_dir = "rdoc"
 
   #List out all the files to be documented.
   rdoc.rdoc_files = ["lib/fOOrth.rb",
+                     "lib/fOOrth/exceptions.rb",
                      "lib/fOOrth/core.rb",
                      "lib/fOOrth/interpreter.rb",
+                     "lib/fOOrth/interpreter/data_stack.rb",
                      "lib/fOOrth/compiler.rb",
                      "lib/fOOrth/main.rb",
-                     "license.txt", "README.txt"]
+                     "license.txt",
+                     "README.txt"]
 
   #Make all access levels visible.
   rdoc.options << '--visibility' << 'private'
 end
 
+#Run the fOOrth test suite.
 Rake::TestTask.new do |t|
   #List out all the test files.
   t.test_files = []
@@ -26,15 +31,12 @@ Rake::TestTask.new do |t|
   t.verbose = false
 end
 
+#Run a scan for smelly code!
 task :reek do |t|
   `reek --no-color lib > reek.txt`
 end
 
-def eval_puts(str)
-  puts str
-  eval str
-end
-
+#Fire up an IRB session with fOOrth preloaded.
 task :console do
   require 'irb'
   require 'irb/completion'
@@ -43,3 +45,17 @@ task :console do
   ARGV.clear
   IRB.start
 end
+
+#Run the Simple Interactive Ruby Environment.
+task :sire do
+  require './lib/fOOrth'
+  require './sire'
+  SIRE.new.run_sire
+end
+
+#Run an Interactive fOOrth Session.
+task :run do
+  require './lib/fOOrth'
+  ARGV.clear
+  XfOOrth::main
+end

sire.rb

@@ -0,0 +1,78 @@
+# coding: utf-8
+# A Simple Interactive Ruby Environment
+
+require 'readline'
+require 'pp'
+
+include Readline
+
+class Object
+  #Generate the class lineage of the object.
+  def classes
+    begin
+      klass = self
+
+      begin
+        klass = klass.class unless klass.instance_of?(Class)
+        print klass
+        klass = klass.superclass
+        print " < " if klass
+      end while klass
+
+      puts
+    end
+  end
+end
+
+class SIRE
+  #Set up the interactive session.
+  def initialize
+    @done    = false
+    @running = false
+
+    puts "Welcome to a Simple Interactive Ruby Environment\n"
+    puts "Use command 'q' to quit.\n\n"
+  end
+
+  #Quit the interactive session.
+  def q
+    @done = true
+    puts
+    "Bye bye for now!"
+  end
+
+  #Run the interactive session.
+  def run_sire
+    until @done
+      begin
+        line = readline('SIRE>', true)
+        @running = true
+        result = eval line
+        @running = false
+        pp result unless line.length == 0
+
+      rescue Interrupt => e
+        if @running
+          @running = false
+          puts "\nExecution Interrupted!"
+          puts "\n#{e.class} detected: #{e}\n"
+          puts e.backtrace
+        else
+          puts "\nI'm outta here!'"
+          @done = true
+        end
+
+        puts "\n"
+
+      rescue Exception => e
+        puts "\n#{e.class} detected: #{e}\n"
+        puts e.backtrace
+        puts
+      end
+    end
+
+    puts "\n\n"
+  end
+
+end
+