asm

fertige_Projekte/Parser.rb

@@ -0,0 +1,68 @@
+class Parser
+  A_INSTRUCTION = /^@\d+$/
+  SYMBOL = /^@[a-zA-Z._\$\d]+$/
+  def self.create_label_hash(hash)
+    (0..15).each do |n|
+      hash["@R#{n}"] = "@#{n.to_s}"
+    end
+    specials = %w(SP LCL ARG THIS THAT)
+    p specials
+    specials.each_with_index do |sym, ind|
+      hash["@" + sym] = "@#{ind}"
+      p hash["@" + sym]
+    end
+  end
+  def initialize(asmfile_path)
+    @file = File.open(asmfile_path, "r")
+    @commands = []
+    @labels = {}
+    @counter = 0
+    @index = 0
+    @available_token = 16
+    Parser.create_label_hash(@labels)
+    readlines
+    p @labels["@SP"]
+  end
+  def readlines
+    while !@file.eof?
+      @current_line = @file.gets.gsub(/\/\/.*/, "").strip
+      if !@current_line.empty?
+        if @current_line[0] == '('
+          @labels["@" + @current_line[1..-2]] = "@#{@counter}"
+        elsif @current_line.match(A_INSTRUCTION)
+          @commands << @current_line
+        elsif @current_line.match(SYMBOL) 
+          @commands << set_tokens_mem_slot(@current_line)
+          @counter += 1
+        else
+          @commands << @current_line
+          @counter += 1
+        end
+      end
+    end
+  end
+  def current_command
+    @commands[@index]
+  end
+  def advance
+    return false if @index == @commands.length
+    @index += 1
+    return @commands[@index]
+  end
+  def has_more_commands
+    @index < @commands.length
+  end
+  def label_line_number(instruction)
+    @labels[instruction]
+  end
+  def set_tokens_mem_slot(line)
+    if !@labels.has_key?(line)
+      @labels[line] = "@#{@available_token}"
+      @available_token += 1
+    end
+    return @labels[line]
+  end
+  def close
+    @file.close
+  end
+end