Refactor, add comments.

Ky6uk · Dec 9, 2014 · c912578 · c912578
1 parent ff6669a
commit c912578
Show file tree

Hide file tree

Showing 2 changed files with 127 additions and 91 deletions.
diff --git a/Ruby/README.md b/Ruby/README.md
@@ -18,4 +18,4 @@ To get some help:
 
 ### VERSION
 
-It is compiled from [petooh-gpl](https://github.com/LavirtheWhiolet/petooh-gpl), commit [81ec5e52461f98d68f3bef310b4cecc8e5b24f77 on Wed Dec 10 00:24:27 2014 +0500](https://github.com/LavirtheWhiolet/petooh-gpl/commit/81ec5e52461f98d68f3bef310b4cecc8e5b24f77).
+It is compiled from [petooh-gpl](https://github.com/LavirtheWhiolet/petooh-gpl), commit [384cd996a2c7246d2a9905b3e9f24c5eb941539d on Wed Dec 10 02:02:00 2014 +0500](https://github.com/LavirtheWhiolet/petooh-gpl/commit/384cd996a2c7246d2a9905b3e9f24c5eb941539d).
diff --git a/Ruby/petooh.rb b/Ruby/petooh.rb
@@ -1,6 +1,115 @@
 #!/usr/bin/env ruby
 # encoding: UTF-8
 
+module PETOOH
+
+  # 
+  # +program+ is an Array of PETOOH keywords (in the form of String-s).
+  #
+  # +debug+ - if true then PETOOH VM state is dumped on each execution step.
+  # 
+  def run(program, debug = false)
+    # Init virtual machine.
+    mem = [0] * 16
+    data_ptr = 0
+    pc = 0  # Index of current instruction in program.
+    # Run!
+    while pc < program.size
+      # Log (if needed).
+      if debug
+        STDERR.puts "MEM: #{mem.join(" ")}"
+        STDERR.puts "PC: #{pc} (#{program[pc]})"
+        STDERR.puts "DP: #{data_ptr} (#{mem[data_ptr]})"
+      end
+      # Analyze current program instruction.
+      case program[pc]
+      when "Kudah"
+        # 
+        data_ptr += 1
+        # Expand memory if needed.
+        if data_ptr >= mem.size
+          mem.concat([0] * 16)
+        end
+        # 
+        pc += 1
+      when "kudah"
+        # 
+        data_ptr -= 1
+        # Convert the machine's state from the form of
+        #   { data_ptr = -1, mem = { -1:x, 0:y, 1:z, … } }
+        # to the form of
+        #   { data_ptr = 0, mem = { 0:x, 1:y, 2:z, … } }
+        if data_ptr < 0
+          mem.unshift(0)
+          data_ptr = 0
+        end
+        # 
+        pc += 1
+      when "Ko"
+        mem[data_ptr] += 1
+        pc += 1
+      when "kO"
+        mem[data_ptr] -= 1
+        pc += 1
+      when "Kukarek"
+        print mem[data_ptr].chr
+        pc += 1
+      when "Kud"
+        if mem[data_ptr] == 0
+          # Increment PC until corresponding "kud" is encountered
+          # (taking nested "Kud"/"kud" into account).
+          nest_level = 1
+          pc += 1
+          while pc < program.size and nest_level > 0
+            case program[pc]
+            when "Kud"
+              nest_level += 1
+            when "kud"
+              nest_level -= 1
+            end
+            pc += 1
+          end
+        else
+          # Just skip the instruction.
+          pc += 1
+        end
+      when "kud"
+        if mem[data_ptr] != 0
+          # Decrement PC until corresponding "Kud" is encountered
+          # (taking nested "Kud"/"kud" into account).
+          nest_level = 1
+          pc -= 1
+          while pc > 0 and nest_level > 0
+            case program[pc]
+            when "Kud"
+              nest_level -= 1
+            when "kud"
+              nest_level += 1
+            end
+            pc -= 1
+          end
+          # Position PC right to the corresponding "Kud".
+          pc += 1
+        else
+          # Just skip the instruction.
+          pc += 1
+        end
+      end
+    end
+  end
+
+  # 
+  # reads PETOOH program from +io+ and parses it into Array of PETOOH
+  # keywords (in the form of String-s).
+  # 
+  def parse(io)
+    yy_parse(io)
+  end
+
+  private
+
+  # Generated by Generator of Parsers of Lavir AKA self-bootstrap.
+
 
 
       # 
@@ -254,100 +363,27 @@ def yy_nontermh(yy_context)
         val = :yy_nil
         yy_char(yy_context) and yy_to_pcv(val)
       end
-
-module PETOOH
-
-  class VM
-
-    def initialize(program)
-    end
-
-  end
-
-end
+
+  # End of generated code.
 
-def run(program)
-  # Init.
-  mem = [0] * 16
-  data_ptr = 0
-  pc = 0
-  # Run!
-  while pc < program.size
-    if $debug
-      STDERR.puts "MEM: #{mem.join(" ")}"
-      STDERR.puts "PC: #{pc} (#{program[pc]})"
-      STDERR.puts "DP: #{data_ptr} (#{mem[data_ptr]})"
-    end
-    case program[pc]
-    when "Kudah"
-      data_ptr += 1
-      if data_ptr >= mem.size
-        mem.concat([0] * 16)
-      end
-      pc += 1
-    when "kudah"
-      data_ptr -= 1
-      if data_ptr < 0
-        mem.unshift(0)
-        data_ptr = 0
-      end
-      pc += 1
-    when "Ko"
-      mem[data_ptr] += 1
-      pc += 1
-    when "kO"
-      mem[data_ptr] -= 1
-      pc += 1
-    when "Kukarek"
-      print mem[data_ptr].chr
-      pc += 1
-    when "Kud"
-      if mem[data_ptr] == 0
-        nest_level = 1
-        pc += 1
-        while pc < program.size and nest_level > 0
-          case program[pc]
-          when "Kud"
-            nest_level += 1
-          when "kud"
-            nest_level -= 1
-          end
-          pc += 1
-        end
-      else
-        pc += 1
-      end
-    when "kud"
-      if mem[data_ptr] != 0
-        nest_level = 1
-        pc -= 1
-        while pc > 0 and nest_level > 0
-          case program[pc]
-          when "Kud"
-            nest_level -= 1
-          when "kud"
-            nest_level += 1
-          end
-          pc -= 1
-        end
-        pc += 1
-      else
-        pc += 1
-      end
-    end
-  end
 end
 
-$debug = false
-
-case ARGV
-when [], ["-h"], ["--help"]
-  puts <<-HELP
+# Main.
+if $0 == __FILE__
+  # Parse args.
+  case ARGV
+  when [], ["-h"], ["--help"]
+    puts <<-HELP
 Usage: ruby #{File.basename(__FILE__)} file
-  HELP
-else
-  File.open(ARGV[0]) do |io|
-    run(yy_parse(io))
+    HELP
+    exit
+  end
+  file = ARGV[0]
+  # Run!
+  include PETOOH
+  File.open(file) do |io|
+    program = parse(io)
+    run program
   end
 end