1 files changed, 136 insertions, 0 deletions
diff --git a/runtime/Ruby/lib/antlr3/streams/interactive.rb b/runtime/Ruby/lib/antlr3/streams/interactive.rb
new file mode 100755
index 0000000..3606050
--- /dev/null
+++ b/runtime/Ruby/lib/antlr3/streams/interactive.rb
@@ -0,0 +1,136 @@
+#!/usr/bin/ruby
+# encoding: utf-8
+
+module ANTLR3
+
+=begin rdoc ANTLR3::Main::InteractiveStringStream
+
+A special stream used in the <b>interactive mode</b> of the Main scripts. It
+uses Readline (if available) or standard IO#gets to fetch data on demand.
+
+=end
+
+class InteractiveStringStream < StringStream
+  
+  if RUBY_VERSION =~ /^1\.9/
+    
+    # creates a new StringStream object where +data+ is the string data to stream.
+    # accepts the following options in a symbol-to-value hash:
+    #
+    # [:file or :name] the (file) name to associate with the stream; default: <tt>'(string)'</tt>
+    # [:line] the initial line number; default: +1+
+    # [:column] the initial column number; default: +0+
+    # 
+    def initialize( options = {}, &block )      # for 1.9
+      @string = ''
+      @data   = []
+      @position = options.fetch :position, 0
+      @line     = options.fetch :line, 1
+      @column   = options.fetch :column, 0
+      @markers  = []
+      mark
+      @initialized = @eof = false
+      @readline = block or raise( ArgumentError, "no line-reading block was provided" )
+      @name ||= options[ :file ] || options[ :name ] || '(interactive)'
+    end
+    
+    def readline
+      @initialized = true
+      unless @eof
+        if line = @readline.call
+          line = line.to_s.encode( Encoding::UTF_8 )
+          @string << line
+          @data.concat( line.codepoints.to_a )
+          return true
+        else
+          @eof = true
+          return false
+        end
+      end
+    end
+    
+  else
+    
+    # creates a new StringStream object where +data+ is the string data to stream.
+    # accepts the following options in a symbol-to-value hash:
+    #
+    # [:file or :name] the (file) name to associate with the stream; default: <tt>'(string)'</tt>
+    # [:line] the initial line number; default: +1+
+    # [:column] the initial column number; default: +0+
+    # 
+    def initialize( options = {}, &block )
+      @string = @data = ''
+      @position = options.fetch :position, 0
+      @line     = options.fetch :line, 1
+      @column   = options.fetch :column, 0
+      @markers = []
+      mark
+      @initialized = @eof = false
+      @readline = block or raise( ArgumentError, "no line-reading block was provided" )
+      @name ||= options[ :file ] || options[ :name ] || '(interactive)'
+    end
+    
+    def readline
+      @initialized = true
+      unless @eof
+        if line = @readline.call
+          @data << line.to_s
+          return true
+        else
+          @eof = true
+          return false
+        end
+      end
+    end
+    
+  end
+  
+  private :readline
+  
+  def consume
+    @position < @data.size and return( super )
+    unless @eof
+      readline
+      consume
+    end
+  end
+  
+  def peek( i = 1 )
+    i.zero? and return 0
+    i += 1 if i < 0
+    index = @position + i - 1
+    index < 0 and return 0
+    
+    if index < @data.size
+      char = @data[ index ]
+    elsif readline
+      peek( i )
+    else EOF
+    end
+  end
+  
+  def look( i = 1 )
+    peek( i ).chr rescue EOF
+  end
+  
+  def substring( start, stop )
+    fill_through( stop )
+    @string[ start .. stop ]
+  end
+  
+private
+  
+  def fill_through( position )
+    @eof and return
+    if @position < 0 then fill_out
+    else readline until ( @data.size > @position or @eof )
+    end
+  end
+  
+  def fill_out
+    @eof and return
+    readline until @eof
+  end
+end
+
+end