use of PageUp and PageDown o scroll suggestions and history. UpArrow and DownArrow now also scroll suggestions if displayed. Otherwise, these keys scroll history.

#region license
// Copyright (c) 2004, Rodrigo B. de Oliveira (rbo@acm.org)
// All rights reserved.
//
// Redistribution and use in source and binary forms, with or without modification,
// are permitted provided that the following conditions are met:
//
//     * Redistributions of source code must retain the above copyright notice,
//     this list of conditions and the following disclaimer.
//     * Redistributions in binary form must reproduce the above copyright notice,
//     this list of conditions and the following disclaimer in the documentation
//     and/or other materials provided with the distribution.
//     * Neither the name of Rodrigo B. de Oliveira nor the names of its
//     contributors may be used to endorse or promote products derived from this
//     software without specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
// ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
// WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
// DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE
// FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
// DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
// SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
// CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
// OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
// THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
#endregion

namespace Boo.Lang.Interpreter

import System
import System.Collections
import System.Collections.Generic
import System.IO
import System.Linq
import System.Text
import System.Text.RegularExpressions
import Boo.Lang.Compiler
import Boo.Lang.Compiler.TypeSystem
import PatternMatching
import Environments

class InteractiveInterpreterConsole:

	public final static HISTORY_FILENAME = "booish_history"
	public final static HISTORY_CAPACITY = 100

	_history = System.Collections.Generic.Queue of string(HISTORY_CAPACITY)
	_historyFile = Path.Combine(Environment.GetFolderPath(Environment.SpecialFolder.LocalApplicationData), HISTORY_FILENAME)
	_historyIndex = 0
	_session = System.Collections.Generic.List of string()

	_buffer = StringBuilder()	#buffer to be executed
	_line = StringBuilder()		#line being edited
	_multiline = false			#is the current line a multi-line?

	[property(BlockStarters, value is not null)]
	_blockStarters = (char(':'), char('\\'),)

	[property(ShowWarnings)]
	_showWarnings = false

	QQBegin = "[|"
	QQEnd= "|]"

	_interpreter as InteractiveInterpreter

	def constructor():
		self(InteractiveInterpreter())

	def constructor(interpreter as InteractiveInterpreter):
		_interpreter = interpreter
		_interpreter.RememberLastValue = true

		DisableColors = not string.IsNullOrEmpty(Environment.GetEnvironmentVariable("BOOISH_DISABLE_COLORS"))
		if not DisableColors: #make sure setting color does not throw an exception
			try:
				Console.ForegroundColor = ConsoleColor.DarkGray
			except:
				DisableColors = true
		DisableAutocompletion = not string.IsNullOrEmpty(Environment.GetEnvironmentVariable("BOOISH_DISABLE_AUTOCOMPLETION"))

		_interpreter.SetValue("load", Load)
		_interpreter.SetValue("save", Save)
		_interpreter.SetValue("quit", Quit)

		LoadHistory()

	def SetValue(name as string, value):
		_interpreter.SetValue(name, value)

	Line:
		get: return _line.ToString()

	LineLastChar:
		get: return (_line.Chars[LineLen-1] if LineLen != 0 else char('\0'))

	LineLen:
		get: return _line.Length
		set: _line.Length = value

	LineIndentLen:
		get: return IndentChars.Length * _indent

	CurrentPrompt as string:
		get: return (BlockPrompt if _indent > 0 else DefaultPrompt)

	PrintModules:
		get: return _interpreter.Pipeline.Find(Boo.Lang.Compiler.Steps.PrintBoo) != -1
		set:
			if value:
				if not PrintModules:
					_interpreter.Pipeline.Add(Boo.Lang.Compiler.Steps.PrintBoo())
			else:
				_interpreter.Pipeline.Remove(Boo.Lang.Compiler.Steps.PrintBoo)

	property DefaultPrompt = ">>> "

	property BlockPrompt = "... "

	property IndentChars = "    "

	property DisableColors = false

	property DisableAutocompletion = false

	# messages from the interpreter (not from user code)
	property InterpreterColor = ConsoleColor.DarkGray

	property PromptColor = ConsoleColor.DarkGreen

	property ExceptionColor = ConsoleColor.DarkRed

	property WarningColor = ConsoleColor.Yellow

	property ErrorColor = ConsoleColor.Red

	property SuggestionsColor = ConsoleColor.DarkYellow

	property SelectedSuggestionColor = ConsoleColor.DarkMagenta

	_selectedSuggestionIndex as int?

	_suggestions as EnvironmentBoundValue[of (object)]

	CanAutoComplete as bool:
		get: return _selectedSuggestionIndex is not null

	private _builtins as (IEntity)
	private _filter as string

	def Eval(code as string):
		try:
			result = _interpreter.Eval(code)
			DisplayResults(result)
			return result
		except x as System.Reflection.TargetInvocationException:
			ConsolePrintException(x.InnerException)
		except x:
			ConsolePrintException(x)

	private def DisplayResults(results as CompilerContext):
		if ShowWarnings:
			DisplayProblems(results.Warnings, WarningColor)
		if not DisplayProblems(results.Errors, ErrorColor):
			ProcessLastValue()

	private def ConsolePrintPrompt():
		ConsolePrintPrompt(true)

	private def ConsolePrintPrompt(autoIndent as bool):
		return if _quit
		WithColor PromptColor:
			Console.Write(CurrentPrompt)
		if autoIndent and CurrentPrompt == BlockPrompt:
			for i in range(_indent):
				WriteIndent()

	private def WithColor(color as ConsoleColor, block as System.Action):
		if DisableColors:
			block()
		else:
			Console.ForegroundColor = color
			try:
				block()
			ensure:
				Console.ResetColor()

	private def ConsolePrintMessage(msg as string):
		WithColor InterpreterColor:
			print msg

	private def ConsolePrintException(e as Exception):
		WithColor ExceptionColor:
			print e

	private def ConsolePrintError(msg as string):
		WithColor ExceptionColor:
			print msg

	private def NewLine():
		Console.Write(Environment.NewLine)

	_numberOfDisplayedSuggestions = 10
	protected def ConsolePrintSuggestions():
		cursorLeft = Console.CursorLeft
		#cursorTop = Console.CursorTop
		NewLine()

		i = 0
		count = 0
		suggestions = SuggestionDescriptions()
		suggestionsCount=len(suggestions)
		while self._selectedSuggestionIndex < 0:
			self._selectedSuggestionIndex+=suggestionsCount
		while self._selectedSuggestionIndex >= suggestionsCount:
			self._selectedSuggestionIndex-=suggestionsCount

		for s in suggestions:
			Console.ForegroundColor = SuggestionsColor if not DisableColors
			//Console.Write(", ") if i > 0
			if count >= _numberOfDisplayedSuggestions:
				Console.WriteLine("... (more candidates)")
				break
			if i+_numberOfDisplayedSuggestions/2 >= _selectedSuggestionIndex or i+_numberOfDisplayedSuggestions >= suggestionsCount:
				if count == 0 and i > 0:
					Console.WriteLine("... (more candidates)")
				if i == _selectedSuggestionIndex:
					Console.ForegroundColor = SelectedSuggestionColor if not DisableColors
				Console.Write(i+1);
				Console.Write(": ");
				Console.WriteLine(s)
				count++
			i++

		Console.ResetColor() if not DisableColors
		#Console.CursorTop = cursorTop
		NewLine()
		ConsolePrintPrompt(false)
		Console.Write(Line)
		Console.CursorLeft = cursorLeft

	def SuggestionDescriptions() as (object):
		return _suggestions.Select(DescriptionsFor).Value

	def DescriptionsFor(suggestions as (object)):
		return array((DescriptionFor(s) for s in suggestions).Distinct())

	def DescriptionFor(s):
		match s:
			case e = IEntity():
				return Boo.Lang.Interpreter.Builtins.DescribeEntity(e)
			otherwise:
				return s.ToString()

	protected def Write(s as string):
		Console.Write(s)
		_line.Append(s)

	protected def WriteIndent():
		Write(IndentChars)

	protected def Indent():
		WriteIndent()
		_indent++

	protected def Unindent():
		return if _indent == 0
		Delete(IndentChars.Length)
		_indent--

	protected def Delete(count as int): #if count is 0, forward-delete
		return if LineLen == 0
		cx = Console.CursorLeft-len(CurrentPrompt)-count
		count=1 if cx >= LineLen and count == 0
		return if cx >= LineLen
		dcount = (count if count != 0 else 1)
		_line.Remove(cx, dcount)
		curX = Console.CursorLeft - count
		Console.CursorLeft = curX
		Console.Write("${_line.ToString(cx, LineLen-cx)} ")
		Console.CursorLeft = curX

	private static re_open = Regex("\\(", RegexOptions.Singleline)
	private static re_close = Regex("\\)", RegexOptions.Singleline)

	def DisplaySuggestions():
		DisplaySuggestions(Line)

	def DisplaySuggestions(query as string):
		return if DisableAutocompletion

		#TODO: FIXME: refactor to one regex?
		p_open = re_open.Matches(query).Count
		p_close = re_close.Matches(query).Count
		if p_open > p_close:
			query = query.Split(" ,(\t".ToCharArray(), 100)[-1]
		else:
			query = query.Split(" ,\t".ToCharArray(), 100)[-1]
		if query.LastIndexOf('.') > 0:
			codeToComplete = query[0:query.LastIndexOf('.')+1]
			_filter = query[query.LastIndexOf('.')+1:]
			_suggestions = (
				_interpreter
				.SuggestCompletionsFor(codeToComplete+"__codecomplete__")
				.Select[of (object)](
					{ es | array(e as object for e in es if e.Name.StartsWith(_filter, StringComparison.InvariantCultureIgnoreCase)) }))

		if _suggestions.Value is null or 0 == len(_suggestions.Value): #suggest a  var
			_filter = query
			_suggestions = EnvironmentBoundValue.Create(
							null,
							array(
								var.Key.ToString() as object
								for var in _interpreter.Values
								if var.ToString().StartsWith(_filter, StringComparison.InvariantCultureIgnoreCase)))

		if _suggestions.Value is null or 0 == len(_suggestions.Value):
			_selectedSuggestionIndex = null
			#Console.Beep() #TODO: flash background?
		elif 1 == len(_suggestions.Value):
			ConsolePrintSuggestions() # write the unique valid suggestion to show the signature of the selected entity
			AutoComplete()
		else:
			ConsolePrintSuggestions()

	def AutoComplete():
		raise InvalidOperationException("no suggestions") if _suggestions.Value is null or _selectedSuggestionIndex is null

		Console.CursorLeft = self.LineLen + len(CurrentPrompt)
		Delete(len(_filter)) if _filter != null
		Write(_suggestions.Select[of string]({ ss | AutoCompletionFor(ss[_selectedSuggestionIndex.Value]) }).Value)

		_selectedSuggestionIndex = null
		_suggestions = EnvironmentBoundValue[of (object)](null, null)

	def AutoCompletionFor(s):
		match s:
			case m = IMethod(Name: name):
				if len(m.GetParameters()) == 0:
					return "$(TrimFilter(name))()"
				return "$(TrimFilter(name))("
			case IEntity(Name: name):
				return TrimFilter(name)
			otherwise:
				return TrimFilter(s.ToString())

	def TrimFilter(s as string):
		#return s[len(_filter):]
		return s # must also replace the filter in command line. thus, do not trim

	private _beforeHistory = string.Empty

	def DisplayHistory():
		if _history.Count == 0 or _historyIndex < 0 or _historyIndex > _history.Count:
			return
		Console.CursorLeft = len(CurrentPrompt)
		Console.Write(string.Empty.PadLeft(LineLen, char(' ')))
		line = _history.ToArray()[_historyIndex]
		LineLen = 0
		Console.CursorLeft = len(CurrentPrompt)
		Write(line)

	def ReadEvalPrintLoop():
		Console.CursorVisible = true
		ConsolePrintPrompt()
		while not _quit:
			ReadEvalPrintLoopStep()
		SaveHistory()
		DisplayGoodbye()

	private def ReadEvalPrintLoopStep():
		cki = Console.ReadKey(true)
		key = cki.Key
		keyChar = cki.KeyChar
		control = false

		newLine = keyChar in Environment.NewLine

		if char.IsControl(keyChar):
			control = true
			if keyChar == char('\t'):
				if LineLen > 0 and (char.IsLetterOrDigit(LineLastChar) or LineLastChar == char('.')):
					_selectedSuggestionIndex = 0
					DisplaySuggestions()
				else:
					Indent()

			# delete the whole line
			if key == ConsoleKey.Escape:
				curX = len(CurrentPrompt)
				sizeL = _line.Length
				_line.Remove(0, sizeL)
				Console.CursorLeft = curX
				Console.Write(string(' '[0], sizeL))
				Console.CursorLeft = curX
				self._selectedSuggestionIndex = null

			#line-editing support
			if not _multiline and LineLen > 0:
				if Console.CursorLeft > len(CurrentPrompt):
					if key == ConsoleKey.Backspace:
						self._selectedSuggestionIndex = null
						if _indent > 0 and LineLen == LineIndentLen:
							Unindent()
						else:
							Delete(1)
					elif key == ConsoleKey.LeftArrow and not self.CanAutoComplete:
						Console.CursorLeft--
				if key == ConsoleKey.Delete:
					self._selectedSuggestionIndex = null
					Delete(0)
				elif key == ConsoleKey.RightArrow and not self.CanAutoComplete:
					if Console.CursorLeft < (len(CurrentPrompt)+LineLen):
						Console.CursorLeft++
				elif key == ConsoleKey.Home:
					Console.CursorLeft = len(CurrentPrompt)
				elif key == ConsoleKey.End:
					Console.CursorLeft = len(CurrentPrompt) + LineLen

			#auto-completion support
			if CanAutoComplete:
				if key == ConsoleKey.LeftArrow or key == ConsoleKey.UpArrow:
					_selectedSuggestionIndex-- # module will run on displaying
					DisplaySuggestions()
				elif key == ConsoleKey.RightArrow or key == ConsoleKey.DownArrow:
					_selectedSuggestionIndex++ # module will run on displaying
					DisplaySuggestions()
				elif key == ConsoleKey.PageUp:
					self._selectedSuggestionIndex -= 10
					self.DisplaySuggestions()
				elif key == ConsoleKey.PageDown:
					self._selectedSuggestionIndex += 10
					self.DisplaySuggestions()
				if newLine:
					AutoComplete()
					return
			else:
				#history support
				if key == ConsoleKey.UpArrow:
					if _historyIndex > 0:
						_historyIndex--
						DisplayHistory()
						self._selectedSuggestionIndex = null
				elif key == ConsoleKey.DownArrow:
					if _historyIndex < _history.Count-1:
						_historyIndex++
						DisplayHistory()
						self._selectedSuggestionIndex = null
				elif key==ConsoleKey.PageDown:
					self._historyIndex += 10
					self._historyIndex = self._history.Count -1 if self._historyIndex >= self._history.Count
					self.DisplayHistory()
				elif key==ConsoleKey.PageUp:
					self._historyIndex -= 10;
					self._historyIndex =0 if self._historyIndex < 0
					self.DisplayHistory()
			if not newLine:
				return

		_selectedSuggestionIndex = null

		cx = Console.CursorLeft-len(CurrentPrompt)
		#multi-line?
		if cx < 0 or LineLen >= Console.WindowWidth-len(CurrentPrompt):
			cx = LineLen
			_multiline = true

		if not newLine:
			#line-editing support
			if cx < LineLen and not _multiline:
				_line.Insert(cx, keyChar) if not control
				Console.Write(_line.ToString(cx, LineLen-cx))
				Console.CursorLeft = len(CurrentPrompt)+cx+1
			else:
				_line.Append(keyChar) if not control
				Console.Write(keyChar)

		if newLine:
			_multiline = false
			Console.Write(Environment.NewLine)

			if not TryRunCommand(Line):
				_buffer.Append(Line)
				_buffer.Append(Environment.NewLine)
				AddToHistory(Line)

				_indent++ if LineLastChar in _blockStarters or Line.EndsWith(QQBegin)
				_indent-- if Line.EndsWith(IndentChars+"pass")
				if Line.EndsWith(QQEnd):
					CheckBooLangCompilerReferenced()
					_indent--

				if _indent <= 0:
					_indent = 0
					try:
						Eval(_buffer.ToString())
					ensure:
						_buffer.Length = 0 #truncate buffer

			LineLen = 0 #truncate line
			ConsolePrintPrompt()

	/* returns false if no command has been processed, true otherwise */
	def TryRunCommand(line as string):
		if not line.StartsWith("/"):
			return false

		cmd = line.Split()

		if len(cmd) == 1:
			if cmd[0] == "/q" or cmd[0] == "/quit":
				Quit()
			elif cmd[0] == "/?" or cmd[0] == "/h" or cmd[0] == "/help":
				DisplayHelp()
			elif cmd[0] == "/g" or cmd[0] == "/globals":
				Eval("globals()")
			else:
				return false

		elif len(cmd) == 2:
			if cmd[0] == "/l" or cmd[0] == "/load":
				Load(cmd[1])
			elif cmd[0] == "/s" or cmd[0] == "/save":
				Save(cmd[1])
			elif cmd[0] == "/d" or cmd[0] == "/describe":
				Eval("describe({0})"%(cmd[1],))
			else:
				return false

		else:
			return false
		return true

	private _indent as int = 0

	def DisplayLogo():
		WithColor InterpreterColor:
			print """Welcome to booish, an interactive interpreter for the boo programming language.
Running boo ${BooVersion} on ${Boo.Lang.Runtime.RuntimeServices.RuntimeDisplayName}.

Enter boo code in the prompt below (or type /help)."""

	def DisplayHelp():
		WithColor InterpreterColor:
			print """The following builtin functions are available :
    /? or /h or /help : display this help
    dir(type) : returns the members of a type
    describe(type) or /d type : describe a type as boo code
    globals() or /g : returns names of all variables known to interpreter
    load(file) or /l file : evals an external boo file
    save(file) or /s file : writes your current booish session into file
    quit() or /q : exits the interpreter"""

	def DisplayGoodbye():	// booish is friendly
		WithColor InterpreterColor:
			print ""
			print "All your boo are belong to us!"

	def LoadHistory():
		try:
			using history = File.OpenText(_historyFile):
				while line = history.ReadLine():
					AddToHistory(line)
		except:
			ConsolePrintError("Cannot load history from '${_historyFile}'")

	def AddToHistory(line as string):
		return if 0 == (len(line) - len(Environment.NewLine))
		_history.Dequeue() if _history.Count >= HISTORY_CAPACITY
		line = line.Replace(Environment.NewLine, "")
		_history.Enqueue(line)
		_historyIndex = _history.Count

	def SaveHistory():
		try:
			using sw = System.IO.File.CreateText(_historyFile):
				for line in _history:
					sw.WriteLine(line)
		except:
			ConsolePrintError("Cannot save history to '${_historyFile}'.")

	def Load([required] path as string):
		if path.EndsWith(".boo"):
			ConsolePrintMessage("Evaluating '${path}' ...")
			DisplayResults(_interpreter.EvalCompilerInput(Boo.Lang.Compiler.IO.FileInput(path)))
		elif File.Exists(path):
			ConsolePrintMessage("Adding reference to '${path}'")
			try:
				_interpreter.References.Add(System.Reflection.Assembly.LoadFrom(path))
			except e:
				ConsolePrintException(e)
		else:
			try:
				a=System.Reflection.Assembly.LoadWithPartialName(path)
				_interpreter.References.Add(a)
				ConsolePrintMessage("Adding reference to assembly '${a.FullName}'")
			except e:
				ConsolePrintError("Error adding reference to assembly '${path}'")
				ConsolePrintException(e)

	private def ProcessLastValue():
		_ = _interpreter.LastValue
		if _ is not null:
			Console.WriteLine(Boo.Lang.Interpreter.Builtins.repr(_))
			_interpreter.SetValue("_", _)

	def Save([required] path as string):
		if path is string.Empty:
			path = "booish_session.boo"
		elif not path.EndsWith(".boo"):
			path = "${path}.boo"
		try:
			using sw = System.IO.File.CreateText(path):
				for line in _session:
					sw.Write(line)
			ConsolePrintMessage("Session saved to '${path}'.")
		except:
			ConsolePrintError("Cannot save to '${path}'. Check if path is valid and has correct permissions.")

	private _quit = false

	def Quit():
		_quit = true

	def DisplayProblems(problems as ICollection, color as ConsoleColor):
		return if problems is null or problems.Count == 0
		WithColor color:
			for problem as duck in problems:
				markLocation(problem.LexicalInfo)
				type = ("ERROR" if problem isa CompilerError else "WARNING")
				Console.WriteLine("${type}: ${problem.Message}")
		return true

	private def markLocation(location as Ast.LexicalInfo):
		pos = location.Column
		Console.WriteLine("--" + "-" * pos + "^") if pos > 0

	private def CheckBooLangCompilerReferenced():
		return if _blcReferenced
		_interpreter.References.Add(typeof(Boo.Lang.Compiler.CompilerContext).Assembly)
		_blcReferenced = true

	_blcReferenced = false

#region license
// Copyright (c) 2004, Rodrigo B. de Oliveira (rbo@acm.org)
// All rights reserved.
//
// Redistribution and use in source and binary forms, with or without modification,
// are permitted provided that the following conditions are met:
//
//     * Redistributions of source code must retain the above copyright notice,
//     this list of conditions and the following disclaimer.
//     * Redistributions in binary form must reproduce the above copyright notice,
//     this list of conditions and the following disclaimer in the documentation
//     and/or other materials provided with the distribution.
//     * Neither the name of Rodrigo B. de Oliveira nor the names of its
//     contributors may be used to endorse or promote products derived from this
//     software without specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
// ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
// WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
// DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE
// FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
// DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
// SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
// CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
// OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
// THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
#endregion

namespace Boo.Lang.Interpreter

import System
import System.Collections
import System.Collections.Generic
import System.IO
import System.Linq
import System.Text
import System.Text.RegularExpressions
import Boo.Lang.Compiler
import Boo.Lang.Compiler.TypeSystem
import PatternMatching
import Environments

class InteractiveInterpreterConsole:

	public final static HISTORY_FILENAME = "booish_history"
	public final static HISTORY_CAPACITY = 100

	_history = System.Collections.Generic.Queue of string(HISTORY_CAPACITY)
	_historyFile = Path.Combine(Environment.GetFolderPath(Environment.SpecialFolder.LocalApplicationData), HISTORY_FILENAME)
	_historyIndex = 0
	_session = System.Collections.Generic.List of string()

	_buffer = StringBuilder()	#buffer to be executed
	_line = StringBuilder()		#line being edited
	_multiline = false			#is the current line a multi-line?

	[property(BlockStarters, value is not null)]
	_blockStarters = (char(':'), char('\\'),)

	[property(ShowWarnings)]
	_showWarnings = false

	QQBegin = "[|"
	QQEnd= "|]"

	_interpreter as InteractiveInterpreter

	def constructor():
		self(InteractiveInterpreter())

	def constructor(interpreter as InteractiveInterpreter):
		_interpreter = interpreter
		_interpreter.RememberLastValue = true

		DisableColors = not string.IsNullOrEmpty(Environment.GetEnvironmentVariable("BOOISH_DISABLE_COLORS"))
		if not DisableColors: #make sure setting color does not throw an exception
			try:
				Console.ForegroundColor = ConsoleColor.DarkGray
			except:
				DisableColors = true
		DisableAutocompletion = not string.IsNullOrEmpty(Environment.GetEnvironmentVariable("BOOISH_DISABLE_AUTOCOMPLETION"))

		_interpreter.SetValue("load", Load)
		_interpreter.SetValue("save", Save)
		_interpreter.SetValue("quit", Quit)

		LoadHistory()

	def SetValue(name as string, value):
		_interpreter.SetValue(name, value)

	Line:
		get: return _line.ToString()

	LineLastChar:
		get: return (_line.Chars[LineLen-1] if LineLen != 0 else char('\0'))

	LineLen:
		get: return _line.Length
		set: _line.Length = value

	LineIndentLen:
		get: return IndentChars.Length * _indent

	CurrentPrompt as string:
		get: return (BlockPrompt if _indent > 0 else DefaultPrompt)

	PrintModules:
		get: return _interpreter.Pipeline.Find(Boo.Lang.Compiler.Steps.PrintBoo) != -1
		set:
			if value:
				if not PrintModules:
					_interpreter.Pipeline.Add(Boo.Lang.Compiler.Steps.PrintBoo())
			else:
				_interpreter.Pipeline.Remove(Boo.Lang.Compiler.Steps.PrintBoo)

	property DefaultPrompt = ">>> "

	property BlockPrompt = "... "

	property IndentChars = "    "

	property DisableColors = false

	property DisableAutocompletion = false

	# messages from the interpreter (not from user code)
	property InterpreterColor = ConsoleColor.DarkGray

	property PromptColor = ConsoleColor.DarkGreen

	property ExceptionColor = ConsoleColor.DarkRed

	property WarningColor = ConsoleColor.Yellow

	property ErrorColor = ConsoleColor.Red

	property SuggestionsColor = ConsoleColor.DarkYellow

	property SelectedSuggestionColor = ConsoleColor.DarkMagenta

	_selectedSuggestionIndex as int?

	_suggestions as EnvironmentBoundValue[of (object)]

	CanAutoComplete as bool:
		get: return _selectedSuggestionIndex is not null

	private _builtins as (IEntity)
	private _filter as string

	def Eval(code as string):
		try:
			result = _interpreter.Eval(code)
			DisplayResults(result)
			return result
		except x as System.Reflection.TargetInvocationException:
			ConsolePrintException(x.InnerException)
		except x:
			ConsolePrintException(x)

	private def DisplayResults(results as CompilerContext):
		if ShowWarnings:
			DisplayProblems(results.Warnings, WarningColor)
		if not DisplayProblems(results.Errors, ErrorColor):
			ProcessLastValue()

	private def ConsolePrintPrompt():
		ConsolePrintPrompt(true)

	private def ConsolePrintPrompt(autoIndent as bool):
		return if _quit
		WithColor PromptColor:
			Console.Write(CurrentPrompt)
		if autoIndent and CurrentPrompt == BlockPrompt:
			for i in range(_indent):
				WriteIndent()

	private def WithColor(color as ConsoleColor, block as System.Action):
		if DisableColors:
			block()
		else:
			Console.ForegroundColor = color
			try:
				block()
			ensure:
				Console.ResetColor()

	private def ConsolePrintMessage(msg as string):
		WithColor InterpreterColor:
			print msg

	private def ConsolePrintException(e as Exception):
		WithColor ExceptionColor:
			print e

	private def ConsolePrintError(msg as string):
		WithColor ExceptionColor:
			print msg

	private def NewLine():
		Console.Write(Environment.NewLine)

	_numberOfDisplayedSuggestions = 10
	protected def ConsolePrintSuggestions():
		cursorLeft = Console.CursorLeft
		#cursorTop = Console.CursorTop
		NewLine()

		i = 0
		count = 0
		suggestions = SuggestionDescriptions()
		suggestionsCount=len(suggestions)
		while self._selectedSuggestionIndex < 0:
			self._selectedSuggestionIndex+=suggestionsCount
		while self._selectedSuggestionIndex >= suggestionsCount:
			self._selectedSuggestionIndex-=suggestionsCount

		for s in suggestions:
			Console.ForegroundColor = SuggestionsColor if not DisableColors
			//Console.Write(", ") if i > 0
			if count >= _numberOfDisplayedSuggestions:
				Console.WriteLine("... (more candidates)")
				break
			if i+_numberOfDisplayedSuggestions/2 >= _selectedSuggestionIndex or i+_numberOfDisplayedSuggestions >= suggestionsCount:
				if count == 0 and i > 0:
					Console.WriteLine("... (more candidates)")
				if i == _selectedSuggestionIndex:
					Console.ForegroundColor = SelectedSuggestionColor if not DisableColors
				Console.Write(i+1);
				Console.Write(": ");
				Console.WriteLine(s)
				count++
			i++

		Console.ResetColor() if not DisableColors
		#Console.CursorTop = cursorTop
		NewLine()
		ConsolePrintPrompt(false)
		Console.Write(Line)
		Console.CursorLeft = cursorLeft

	def SuggestionDescriptions() as (object):
		return _suggestions.Select(DescriptionsFor).Value

	def DescriptionsFor(suggestions as (object)):
		return array((DescriptionFor(s) for s in suggestions).Distinct())

	def DescriptionFor(s):
		match s:
			case e = IEntity():
				return Boo.Lang.Interpreter.Builtins.DescribeEntity(e)
			otherwise:
				return s.ToString()

	protected def Write(s as string):
		Console.Write(s)
		_line.Append(s)

	protected def WriteIndent():
		Write(IndentChars)

	protected def Indent():
		WriteIndent()
		_indent++

	protected def Unindent():
		return if _indent == 0
		Delete(IndentChars.Length)
		_indent--

	protected def Delete(count as int): #if count is 0, forward-delete
		return if LineLen == 0
		cx = Console.CursorLeft-len(CurrentPrompt)-count
		count=1 if cx >= LineLen and count == 0
		return if cx >= LineLen
		dcount = (count if count != 0 else 1)
		_line.Remove(cx, dcount)
		curX = Console.CursorLeft - count
		Console.CursorLeft = curX
		Console.Write("${_line.ToString(cx, LineLen-cx)} ")
		Console.CursorLeft = curX

	private static re_open = Regex("\\(", RegexOptions.Singleline)
	private static re_close = Regex("\\)", RegexOptions.Singleline)

	def DisplaySuggestions():
		DisplaySuggestions(Line)

	def DisplaySuggestions(query as string):
		return if DisableAutocompletion

		#TODO: FIXME: refactor to one regex?
		p_open = re_open.Matches(query).Count
		p_close = re_close.Matches(query).Count
		if p_open > p_close:
			query = query.Split(" ,(\t".ToCharArray(), 100)[-1]
		else:
			query = query.Split(" ,\t".ToCharArray(), 100)[-1]
		if query.LastIndexOf('.') > 0:
			codeToComplete = query[0:query.LastIndexOf('.')+1]
			_filter = query[query.LastIndexOf('.')+1:]
			_suggestions = (
				_interpreter
				.SuggestCompletionsFor(codeToComplete+"__codecomplete__")
				.Select[of (object)](
					{ es | array(e as object for e in es if e.Name.StartsWith(_filter, StringComparison.InvariantCultureIgnoreCase)) }))

		if _suggestions.Value is null or 0 == len(_suggestions.Value): #suggest a  var
			_filter = query
			_suggestions = EnvironmentBoundValue.Create(
							null,
							array(
								var.Key.ToString() as object
								for var in _interpreter.Values
								if var.ToString().StartsWith(_filter, StringComparison.InvariantCultureIgnoreCase)))

		if _suggestions.Value is null or 0 == len(_suggestions.Value):
			_selectedSuggestionIndex = null
			#Console.Beep() #TODO: flash background?
		elif 1 == len(_suggestions.Value):
			ConsolePrintSuggestions() # write the unique valid suggestion to show the signature of the selected entity
			AutoComplete()
		else:
			ConsolePrintSuggestions()

	def AutoComplete():
		raise InvalidOperationException("no suggestions") if _suggestions.Value is null or _selectedSuggestionIndex is null

		Console.CursorLeft = self.LineLen + len(CurrentPrompt)
		Delete(len(_filter)) if _filter != null
		Write(_suggestions.Select[of string]({ ss | AutoCompletionFor(ss[_selectedSuggestionIndex.Value]) }).Value)

		_selectedSuggestionIndex = null
		_suggestions = EnvironmentBoundValue[of (object)](null, null)

	def AutoCompletionFor(s):
		match s:
			case m = IMethod(Name: name):
				if len(m.GetParameters()) == 0:
					return "$(TrimFilter(name))()"
				return "$(TrimFilter(name))("
			case IEntity(Name: name):
				return TrimFilter(name)
			otherwise:
				return TrimFilter(s.ToString())

	def TrimFilter(s as string):
		#return s[len(_filter):]
		return s # must also replace the filter in command line. thus, do not trim

	private _beforeHistory = string.Empty

	def DisplayHistory():
		if _history.Count == 0 or _historyIndex < 0 or _historyIndex > _history.Count:
			return
		Console.CursorLeft = len(CurrentPrompt)
		Console.Write(string.Empty.PadLeft(LineLen, char(' ')))
		line = _history.ToArray()[_historyIndex]
		LineLen = 0
		Console.CursorLeft = len(CurrentPrompt)
		Write(line)

	def ReadEvalPrintLoop():
		Console.CursorVisible = true
		ConsolePrintPrompt()
		while not _quit:
			ReadEvalPrintLoopStep()
		SaveHistory()
		DisplayGoodbye()

	private def ReadEvalPrintLoopStep():
		cki = Console.ReadKey(true)
		key = cki.Key
		keyChar = cki.KeyChar
		control = false

		newLine = keyChar in Environment.NewLine

		if char.IsControl(keyChar):
			control = true
			if keyChar == char('\t'):
				if LineLen > 0 and (char.IsLetterOrDigit(LineLastChar) or LineLastChar == char('.')):
					_selectedSuggestionIndex = 0
					DisplaySuggestions()
				else:
					Indent()

			# delete the whole line
			if key == ConsoleKey.Escape:
				curX = len(CurrentPrompt)
				sizeL = _line.Length
				_line.Remove(0, sizeL)
				Console.CursorLeft = curX
				Console.Write(string(' '[0], sizeL))
				Console.CursorLeft = curX
				self._selectedSuggestionIndex = null

			#line-editing support
			if not _multiline and LineLen > 0:
				if Console.CursorLeft > len(CurrentPrompt):
					if key == ConsoleKey.Backspace:
						self._selectedSuggestionIndex = null
						if _indent > 0 and LineLen == LineIndentLen:
							Unindent()
						else:
							Delete(1)
					elif key == ConsoleKey.LeftArrow and not self.CanAutoComplete:
						Console.CursorLeft--
				if key == ConsoleKey.Delete:
					self._selectedSuggestionIndex = null
					Delete(0)
				elif key == ConsoleKey.RightArrow and not self.CanAutoComplete:
					if Console.CursorLeft < (len(CurrentPrompt)+LineLen):
						Console.CursorLeft++
				elif key == ConsoleKey.Home:
					Console.CursorLeft = len(CurrentPrompt)
				elif key == ConsoleKey.End:
					Console.CursorLeft = len(CurrentPrompt) + LineLen

			#history support
			if key == ConsoleKey.UpArrow:
				if _historyIndex > 0:
					_historyIndex--
					DisplayHistory()
					self._selectedSuggestionIndex = null
			elif key == ConsoleKey.DownArrow:
				if _historyIndex < _history.Count-1:
					_historyIndex++
					DisplayHistory()
					self._selectedSuggestionIndex = null

			#auto-completion support
			if CanAutoComplete:
				if key == ConsoleKey.LeftArrow:
					_selectedSuggestionIndex-- # module will run on displaying
					DisplaySuggestions()
				elif key == ConsoleKey.RightArrow:
					_selectedSuggestionIndex++ # module will run on displaying
					DisplaySuggestions()
				if newLine:
					AutoComplete()
					return
			if not newLine:
				return

		_selectedSuggestionIndex = null

		cx = Console.CursorLeft-len(CurrentPrompt)
		#multi-line?
		if cx < 0 or LineLen >= Console.WindowWidth-len(CurrentPrompt):
			cx = LineLen
			_multiline = true

		if not newLine:
			#line-editing support
			if cx < LineLen and not _multiline:
				_line.Insert(cx, keyChar) if not control
				Console.Write(_line.ToString(cx, LineLen-cx))
				Console.CursorLeft = len(CurrentPrompt)+cx+1
			else:
				_line.Append(keyChar) if not control
				Console.Write(keyChar)

		if newLine:
			_multiline = false
			Console.Write(Environment.NewLine)

			if not TryRunCommand(Line):
				_buffer.Append(Line)
				_buffer.Append(Environment.NewLine)
				AddToHistory(Line)

				_indent++ if LineLastChar in _blockStarters or Line.EndsWith(QQBegin)
				_indent-- if Line.EndsWith(IndentChars+"pass")
				if Line.EndsWith(QQEnd):
					CheckBooLangCompilerReferenced()
					_indent--

				if _indent <= 0:
					_indent = 0
					try:
						Eval(_buffer.ToString())
					ensure:
						_buffer.Length = 0 #truncate buffer

			LineLen = 0 #truncate line
			ConsolePrintPrompt()

	/* returns false if no command has been processed, true otherwise */
	def TryRunCommand(line as string):
		if not line.StartsWith("/"):
			return false

		cmd = line.Split()

		if len(cmd) == 1:
			if cmd[0] == "/q" or cmd[0] == "/quit":
				Quit()
			elif cmd[0] == "/?" or cmd[0] == "/h" or cmd[0] == "/help":
				DisplayHelp()
			elif cmd[0] == "/g" or cmd[0] == "/globals":
				Eval("globals()")
			else:
				return false

		elif len(cmd) == 2:
			if cmd[0] == "/l" or cmd[0] == "/load":
				Load(cmd[1])
			elif cmd[0] == "/s" or cmd[0] == "/save":
				Save(cmd[1])
			elif cmd[0] == "/d" or cmd[0] == "/describe":
				Eval("describe({0})"%(cmd[1],))
			else:
				return false

		else:
			return false
		return true

	private _indent as int = 0

	def DisplayLogo():
		WithColor InterpreterColor:
			print """Welcome to booish, an interactive interpreter for the boo programming language.
Running boo ${BooVersion} on ${Boo.Lang.Runtime.RuntimeServices.RuntimeDisplayName}.

Enter boo code in the prompt below (or type /help)."""

	def DisplayHelp():
		WithColor InterpreterColor:
			print """The following builtin functions are available :
    /? or /h or /help : display this help
    dir(type) : returns the members of a type
    describe(type) or /d type : describe a type as boo code
    globals() or /g : returns names of all variables known to interpreter
    load(file) or /l file : evals an external boo file
    save(file) or /s file : writes your current booish session into file
    quit() or /q : exits the interpreter"""

	def DisplayGoodbye():	// booish is friendly
		WithColor InterpreterColor:
			print ""
			print "All your boo are belong to us!"

	def LoadHistory():
		try:
			using history = File.OpenText(_historyFile):
				while line = history.ReadLine():
					AddToHistory(line)
		except:
			ConsolePrintError("Cannot load history from '${_historyFile}'")

	def AddToHistory(line as string):
		return if 0 == (len(line) - len(Environment.NewLine))
		_history.Dequeue() if _history.Count >= HISTORY_CAPACITY
		line = line.Replace(Environment.NewLine, "")
		_history.Enqueue(line)
		_historyIndex = _history.Count

	def SaveHistory():
		try:
			using sw = System.IO.File.CreateText(_historyFile):
				for line in _history:
					sw.WriteLine(line)
		except:
			ConsolePrintError("Cannot save history to '${_historyFile}'.")

	def Load([required] path as string):
		if path.EndsWith(".boo"):
			ConsolePrintMessage("Evaluating '${path}' ...")
			DisplayResults(_interpreter.EvalCompilerInput(Boo.Lang.Compiler.IO.FileInput(path)))
		elif File.Exists(path):
			ConsolePrintMessage("Adding reference to '${path}'")
			try:
				_interpreter.References.Add(System.Reflection.Assembly.LoadFrom(path))
			except e:
				ConsolePrintException(e)
		else:
			try:
				a=System.Reflection.Assembly.LoadWithPartialName(path)
				_interpreter.References.Add(a)
				ConsolePrintMessage("Adding reference to assembly '${a.FullName}'")
			except e:
				ConsolePrintError("Error adding reference to assembly '${path}'")
				ConsolePrintException(e)

	private def ProcessLastValue():
		_ = _interpreter.LastValue
		if _ is not null:
			Console.WriteLine(Boo.Lang.Interpreter.Builtins.repr(_))
			_interpreter.SetValue("_", _)

	def Save([required] path as string):
		if path is string.Empty:
			path = "booish_session.boo"
		elif not path.EndsWith(".boo"):
			path = "${path}.boo"
		try:
			using sw = System.IO.File.CreateText(path):
				for line in _session:
					sw.Write(line)
			ConsolePrintMessage("Session saved to '${path}'.")
		except:
			ConsolePrintError("Cannot save to '${path}'. Check if path is valid and has correct permissions.")

	private _quit = false

	def Quit():
		_quit = true

	def DisplayProblems(problems as ICollection, color as ConsoleColor):
		return if problems is null or problems.Count == 0
		WithColor color:
			for problem as duck in problems:
				markLocation(problem.LexicalInfo)
				type = ("ERROR" if problem isa CompilerError else "WARNING")
				Console.WriteLine("${type}: ${problem.Message}")
		return true

	private def markLocation(location as Ast.LexicalInfo):
		pos = location.Column
		Console.WriteLine("--" + "-" * pos + "^") if pos > 0

	private def CheckBooLangCompilerReferenced():
		return if _blcReferenced
		_interpreter.References.Add(typeof(Boo.Lang.Compiler.CompilerContext).Assembly)
		_blcReferenced = true

	_blcReferenced = false


CodeMethodReturnStatement.Expression can be null.

git-svn-id: fcce7d6ce0ac15bf24f68871b5145d46fc068279@2319 2c1201b4-01cd-e047-a400-b836ae1fbc61

#region license
// Copyright (c) 2004, Rodrigo B. de Oliveira (rbo@acm.org)
// All rights reserved.
//
// Redistribution and use in source and binary forms, with or without modification,
// are permitted provided that the following conditions are met:
//
//     * Redistributions of source code must retain the above copyright notice,
//     this list of conditions and the following disclaimer.
//     * Redistributions in binary form must reproduce the above copyright notice,
//     this list of conditions and the following disclaimer in the documentation
//     and/or other materials provided with the distribution.
//     * Neither the name of Rodrigo B. de Oliveira nor the names of its
//     contributors may be used to endorse or promote products derived from this
//     software without specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
// ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
// WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
// DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE
// FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
// DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
// SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
// CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
// OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
// THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
#endregion

// authors:
// Arron Washington
// Ian MacLean (original C# version)

//See also:
//http://svn.myrealbox.com/viewcvs/trunk/mcs/class/System/Microsoft.CSharp/CSharpCodeGenerator.cs?view=auto
//http://svn.myrealbox.com/viewcvs/trunk/mcs/class/System/Microsoft.VisualBasic/VBCodeGenerator.cs?view=auto

namespace Boo.Lang.CodeDom

import System
import System.CodeDom
import System.CodeDom.Compiler
import System.IO
import System.Reflection
import System.Collections
import System.Text.RegularExpressions
import System.Globalization

class BooCodeGenerator(CodeGenerator):
	static _NET_2_0 as bool = System.Environment.Version >= System.Version(2, 0)

	static primitives = { "System.Double" : "double",
						"System.Single" : "single",
						"System.Int32" : "int",
						"System.Int64" : "long",
						"System.Int16" : "short",
						"System.UInt16" : "ushort",
						"System.Boolean" : "bool",
						"System.Char" : "char",
						"System.String" : "string",
						"System.Object" : "object",
						"System.Void" : "void"}

	protected NullToken as string:
		get:
			return "null"

	protected override def OutputType(typeRef as CodeTypeReference):
		Output.Write(GetTypeOutput(typeRef))

	protected override def GenerateArrayCreateExpression(exp as CodeArrayCreateExpression) :
		if exp.Initializers is not null and exp.Size == 0 and exp.SizeExpression is null:
			Output.Write("(")
			if exp.CreateType is not null:
				Output.Write("of ")
				OutputType(exp.CreateType)
				Output.Write(": ")
			OutputExpressionList(exp.Initializers)
			//no trailing comma needed for single item with "of" type
			if exp.Initializers.Count==0 or (exp.Initializers.Count==1 and not exp.CreateType):
				Output.Write(",")
			Output.Write(")")
		else:
			Output.Write("array(")
			OutputType(exp.CreateType)
			Output.Write(", ")
			if exp.SizeExpression is not null:
				GenerateExpression(exp.SizeExpression)
			else:
				Output.Write(exp.Size)
			Output.Write(")")

	protected override def GenerateBaseReferenceExpression(e as CodeBaseReferenceExpression) :
		Output.Write("super")

	protected override def GenerateCastExpression(e as CodeCastExpression) :
		Output.Write("cast(")
		OutputType(e.TargetType)
		Output.Write(",")
		GenerateExpression(e.Expression)
		Output.Write(")")

	protected override def GenerateDelegateCreateExpression(e as CodeDelegateCreateExpression) :
		GenerateExpression(e.TargetObject)
		Output.Write(".${e.MethodName} as ")
		OutputType(e.DelegateType)

	protected override def GenerateFieldReferenceExpression(e as CodeFieldReferenceExpression):
		MemberReference(e.TargetObject, e.FieldName)

	protected override def GenerateArgumentReferenceExpression(e as CodeArgumentReferenceExpression) :
		Output.Write(e.ParameterName)

	protected override def GenerateVariableReferenceExpression(e as CodeVariableReferenceExpression) :
		Output.Write(e.VariableName)

	protected override def GenerateIndexerExpression(e as CodeIndexerExpression) :
		Indexer(e.TargetObject, e.Indices)

	protected override def GenerateArrayIndexerExpression(e as CodeArrayIndexerExpression) :
		Indexer(e.TargetObject, e.Indices)

	protected override def GenerateMethodInvokeExpression(e as CodeMethodInvokeExpression) :
		Invocation(e.Method, e.Parameters)

	protected override def GenerateMethodReferenceExpression(e as CodeMethodReferenceExpression) :
		MemberReference(e.TargetObject, e.MethodName)
	protected override def GenerateEventReferenceExpression(e as CodeEventReferenceExpression) :
		MemberReference(e.TargetObject, e.EventName)

	protected override def GenerateDelegateInvokeExpression(e as CodeDelegateInvokeExpression) :
		Invocation(e.TargetObject, e.Parameters)

	protected override def GenerateObjectCreateExpression(e as CodeObjectCreateExpression) :
		OutputType(e.CreateType)
		Output.Write("(")
		OutputExpressionList(e.Parameters)
		Output.Write(")")

	protected override def GeneratePropertyReferenceExpression(e as CodePropertyReferenceExpression) :
		MemberReference(e.TargetObject, e.PropertyName)

	protected override def GeneratePropertySetValueReferenceExpression(e as CodePropertySetValueReferenceExpression) :
		Output.Write("value")

	protected override def GenerateThisReferenceExpression(e as CodeThisReferenceExpression) :
		Output.Write("self")

	protected override def GenerateExpressionStatement(e as CodeExpressionStatement) :
		GenerateExpression(e.Expression)
		Output.WriteLine()

	protected override def GenerateIterationStatement(e as CodeIterationStatement):
		if e.InitStatement:
			GenerateStatement(e.InitStatement)
		Output.Write("while ")
		GenerateExpression(e.TestExpression)
		BeginBlock()
		if e.Statements and e.Statements.IsValid():
			GenerateStatements(e.Statements)
		if e.IncrementStatement:
			GenerateStatement(e.IncrementStatement)
		else:
			passcheck(e.Statements)
		EndBlock()

	protected override def GenerateThrowExceptionStatement(e as CodeThrowExceptionStatement) :
		Output.Write("raise ")
		GenerateExpression(e.ToThrow)
		Output.WriteLine()

	protected override def GenerateComment(comment as CodeComment) :
		//TODO: check comment.DocComment when boo doc format is available
		commentSymbol = "#"
		txt = comment.Text

		Output.Write(commentSymbol + " ")

		i = 0
		while i<len(txt):
			rawArrayIndexing:
				Output.Write(txt[i])
				if txt[i] == char('\r'):
					if i<len(txt)-1 and txt[i+1]==char('\n'):
						continue
					Output.Write(commentSymbol)
				elif txt[i] == char('\n'):
					Output.Write(commentSymbol)
			++i
		Output.WriteLine()

	protected override def GenerateMethodReturnStatement(e as CodeMethodReturnStatement) :
		if e.Expression is null:
			Output.WriteLine("return")
			return
		Output.Write("return ")
		GenerateExpression(e.Expression)
		Output.WriteLine()

	protected override def GenerateConditionStatement(e as CodeConditionStatement) :
		Output.Write("if ")
		GenerateExpression(e.Condition)
		BeginBlock()
		GenerateStatements(e.TrueStatements)
		passcheck(e.TrueStatements)
		EndBlock(false)
		if e.FalseStatements and e.FalseStatements.IsValid():
			Output.Write("else")
			BeginBlock()
			GenerateStatements(e.FalseStatements)
			passcheck(e.FalseStatements)
			EndBlock(false)
		End()

	protected override def GenerateTryCatchFinallyStatement(e as CodeTryCatchFinallyStatement) :
		Output.Write("try")
		BeginBlock()
		GenerateStatements(e.TryStatements)
		passcheck(e.TryStatements)
		EndBlock(false)
		for exp as CodeCatchClause in e.CatchClauses:
			Output.Write("except ")
			Output.Write("${exp.LocalName} as ")
			OutputType(exp.CatchExceptionType)
			BeginBlock()
			GenerateStatements(exp.Statements)
			passcheck(exp.Statements)
			EndBlock(false)

		if e.FinallyStatements and e.FinallyStatements.Count > 0:
			Output.Write("ensure")
			BeginBlock()
			GenerateStatements(e.FinallyStatements)
			passcheck(e.FinallyStatements)
			EndBlock(false)
		End()

	protected override def GenerateAssignStatement(e as CodeAssignStatement) :
		GenerateExpression(e.Left)
		Output.Write(" = ")
		GenerateExpression(e.Right)
		Output.WriteLine()
	protected override def GenerateAttachEventStatement(e as CodeAttachEventStatement) :
		GenerateExpression(e.Event)
		Output.Write(" += ")
		GenerateExpression(e.Listener)
		Output.WriteLine()
	protected override def GenerateRemoveEventStatement(e as CodeRemoveEventStatement) :
		GenerateExpression(e.Event)
		Output.Write(" -= ")
		GenerateExpression(e.Listener)
		Output.WriteLine()
	protected override def GenerateGotoStatement(e as CodeGotoStatement) :
		Output.WriteLine("goto ${e.Label}")
	protected override def GenerateLabeledStatement(e as CodeLabeledStatement) :
		Output.WriteLine(":${e.Label}")
		if e.Statement:
			GenerateStatement(e.Statement)
	protected override def GenerateVariableDeclarationStatement(e as CodeVariableDeclarationStatement) :
		Output.Write("${e.Name} as ")
		OutputType(e.Type)
		if e.InitExpression:
			Output.Write(" = ")
			GenerateExpression(e.InitExpression)
		Output.WriteLine()
	protected override def GenerateLinePragmaStart(e as CodeLinePragma) :
		pass

	protected override def GenerateLinePragmaEnd(e as CodeLinePragma) :
		pass

	protected override def GenerateEvent(e as CodeMemberEvent, c as CodeTypeDeclaration) :

		if e.PrivateImplementationType:
			raise "Does not support private implementation type."
		if e.ImplementationTypes.IsValid():
			raise "Does not implement these types: ${join(e.ImplementationTypes)}"
		e.Attributes |= MemberAttributes.Final

		ModifiersAndAttributes(e)

		Output.Write("event ${e.Name} as ")
		OutputType(e.Type)
		Output.WriteLine()
	protected override def GenerateField(e as CodeMemberField) :

		ModifiersAndAttributes(e)
		Output.Write("${e.Name} as ")
		OutputType(e.Type)
		if e.InitExpression:
			Output.Write(" = ")
			GenerateExpression(e.InitExpression)
		Output.WriteLine()

	protected override def GenerateSnippetMember(e as CodeSnippetTypeMember) :
		if e.CustomAttributes:
			OutputAttributes(e.CustomAttributes, null, false)
		Output.WriteLine(FixIndent(e.Text, Options.IndentString, Indent, false))

	protected override def GenerateSnippetExpression(e as CodeSnippetExpression) :
		//Output.Write("("+e.Value+")")
		Output.Write(e.Value)

	protected override def GenerateSnippetCompileUnit(e as CodeSnippetCompileUnit) :
		Output.WriteLine(FixIndent(e.Value, Options.IndentString, Indent, false))

	protected override def GenerateSnippetStatement(e as CodeSnippetStatement) :
		if _NET_2_0:
			Output.WriteLine(e.Value)
		else:
			Output.WriteLine(FixIndent(e.Value, Options.IndentString, Indent, false))

	protected override def GenerateEntryPointMethod(e as CodeEntryPointMethod, c as CodeTypeDeclaration) :
		Method(e, "Main")

	protected override def GenerateMethod(e as CodeMemberMethod, c as CodeTypeDeclaration) :
		Method(e, e.Name)

	protected override def GenerateProperty(e as CodeMemberProperty, c as CodeTypeDeclaration) :
		ModifiersAndAttributes(e)

		if (e.Parameters.Count > 0
			and string.Compare(e.Name, "Item", true, CultureInfo.InvariantCulture) == 0):
			Output.Write(" self")
		else:
			Output.Write(" ${e.Name}")
		if len(e.Parameters) > 0:
			Output.Write("[")
			OutputParameters(e.Parameters)
			Output.Write("]")
		Output.Write(" as ")
		OutputType(e.Type)
		BeginBlock()
		if e.HasGet:
			Output.Write("get")
			BeginBlock()
			GenerateStatements(e.GetStatements)
			passcheck(e.GetStatements)
			EndBlock() //TODO: Change to EndBlock(false) when BOO-631 accepted
		if e.HasSet:
			Output.Write("set")
			BeginBlock()
			GenerateStatements(e.SetStatements)
			passcheck(e.SetStatements)
			EndBlock() //TODO: Change to EndBlock(false) when BOO-631 accepted
		EndBlock()

	protected override def GenerateConstructor(e as CodeConstructor, c as CodeTypeDeclaration) :
		e.Attributes |= MemberAttributes.Final
		Method(e, "constructor")

	protected override def GenerateTypeConstructor(e as CodeTypeConstructor) :
		e.Attributes |= MemberAttributes.Static
		e.Attributes |= MemberAttributes.Public
		e.Parameters.Clear()
		Method(e, "constructor")

	protected override def GenerateTypeStart(e as CodeTypeDeclaration):
		if e.CustomAttributes:
			OutputAttributes(e.CustomAttributes, null, false)
		if e isa CodeTypeDelegate:
			GenerateDelegate(e)
			return

		//TODO: move this to an override of OutputTypeAttributes

		//FIXME: When boo gets preprocessor directives, i.e. #if NET_2_0
		//Til then we have to partially rely on super.OutputTypeAttributes

		//output "final", since super.OutputTypeAttributes outputs "sealed"
		if e.TypeAttributes & TypeAttributes.Sealed == TypeAttributes.Sealed:
			Output.Write("final ")

			//remove sealed from attributes:

			//FIXME: when boo enum processing fixed
			//e.TypeAttributes &= ~TypeAttributes.Sealed
			e.TypeAttributes &= cast(TypeAttributes,~cast(int,TypeAttributes.Sealed))

		visibility = e.TypeAttributes & TypeAttributes.VisibilityMask
		if visibility == TypeAttributes.Public or visibility == TypeAttributes.NestedPublic:
			pass //Output.Write("public ") //public by default
		elif visibility == TypeAttributes.NestedPrivate:
			Output.Write("private ")
		elif (visibility == TypeAttributes.NotPublic or
			TypeAttributes.NestedFamANDAssem or
			TypeAttributes.NestedAssembly):
			Output.Write("internal ")
		elif visibility == TypeAttributes.NestedFamily:
			//FIXME: BOO-666
			Output.Write("protected ")
		elif visibility == TypeAttributes.NestedFamORAssem:
			//FIXME: BOO-666
			Output.Write("internal ")

		//super OutputTypeAttributes ignores TypeAttributes.NotPublic (internal)
		//FIXME: when boo enum processing fixed
		//e.TypeAttributes &= ~TypeAttributes.VisibilityMask
		e.TypeAttributes &= cast(TypeAttributes,~cast(int,TypeAttributes.VisibilityMask))
		e.TypeAttributes |= TypeAttributes.NotPublic //not really nec. since val is 0

		//TODO: Remove call to OutputTypeAttributes
		OutputTypeAttributes(e.TypeAttributes, e.IsStruct, e.IsEnum)
		/////////////////////////////////////

		Output.Write("${e.Name}(")
		for index in range(len(e.BaseTypes)):
			var as CodeTypeReference = e.BaseTypes[index]
			OutputType(var)
			continue unless index + 1 != e.BaseTypes.Count
			Output.Write(",")
		Output.Write(")")
		BeginBlock()
		#Ah hah hah, yeah, no. Empty class.
		passcheck(e.Members)

	private def GenerateDelegate(e as CodeTypeDelegate):
		if e.TypeAttributes & TypeAttributes.Sealed == TypeAttributes.Sealed:
			Output.Write("final ")
		if e.TypeAttributes & TypeAttributes.NestedFamORAssem == TypeAttributes.Public:
			Output.Write("public ")
		Output.Write("callable ${e.Name}(")
		OutputParameters(e.Parameters)
		Output.Write(") as ")
		OutputType(e.ReturnType)

	protected override def GenerateTypeEnd(e as CodeTypeDeclaration) :
		EndBlock()

	protected override def GenerateNamespaceStart(e as CodeNamespace) :
		if e and e.Name and e.Name != string.Empty:
			Output.WriteLine("namespace ${e.Name}")

	protected override def GenerateNamespaceEnd(e as CodeNamespace) :
		pass

	protected override def GenerateNamespaceImport(e as CodeNamespaceImport) :
		Output.WriteLine("import ${e.Namespace}")

	protected override def GenerateAttributeDeclarationsStart(attributes as CodeAttributeDeclarationCollection) :
		Output.Write("[")

	protected override def GenerateAttributeDeclarationsEnd(attributes as CodeAttributeDeclarationCollection) :
		Output.Write("]")

	protected override def Supports(support as GeneratorSupport) as bool:
		return true

	protected override def IsValidIdentifier(value as string) as bool:
		return true

	protected override def CreateEscapedIdentifier(value as string) as string:
		return value

	protected override def CreateValidIdentifier(value as string) as string:
		return value

	protected override def GetTypeOutput(typeRef as CodeTypeReference) as string:
		if typeRef.ArrayElementType:
			out = GetTypeOutput(typeRef.ArrayElementType)
		elif typeRef.BaseType in primitives:
			out = primitives[typeRef.BaseType]
		else:
			out = typeRef.BaseType

		if typeRef.ArrayRank == 0:
			return out
		elif typeRef.ArrayRank == 1:
			return "(${out})"
		else:
			return "(${out}, ${typeRef.ArrayRank})"

	protected override def QuoteSnippetString(snippet as string) as string:
		s = snippet.Replace("\\", "\\\\")
		s = s.Replace("\"", "\\\"")
		s = s.Replace("\t", "\\t")
		s = s.Replace("\r", "\\r")
		s = s.Replace("\n", "\\n")
		return "\"" + s + "\""

	def Method(method as duck, name as string):
		ModifiersAndAttributes(method)
		Output.Write("def ${name}(")
		OutputParameters(method.Parameters)
		Output.Write(")")
		unless GetTypeOutput(method.ReturnType) == "void":
			Output.Write(" as ")
			OutputType(method.ReturnType)
		if method.ReturnTypeCustomAttributes:
			OutputAttributes(method.ReturnTypeCustomAttributes, null, true)
		BeginBlock()
		ctor = method as CodeConstructor
		do_pass = true
		if ctor:
			if ctor.BaseConstructorArgs.IsValid():
				Output.Write("super(")
				OutputExpressionList(ctor.BaseConstructorArgs)
				Output.WriteLine(")")
				do_pass = false
			if ctor.ChainedConstructorArgs.IsValid():
				Output.Write("self(")
				OutputExpressionList(ctor.ChainedConstructorArgs)
				Output.WriteLine(")")
				do_pass = false
		GenerateStatements(method.Statements)
		if do_pass:
			passcheck(method.Statements)
		EndBlock()

	def MemberReference(target as CodeExpression, member as string):
		if target: #target.method( ... )
			GenerateExpression(target)
			Output.Write(".${member}")
		else: #method( ... )
			Output.Write(member)

	def Indexer(target as CodeExpression, indices as CodeExpressionCollection):
		GenerateExpression(target)
		Output.Write("[")
		OutputExpressionList(indices)
		Output.Write("]")

	def Invocation(target as CodeExpression, parameters as CodeExpressionCollection):
		GenerateExpression(target)
		Output.Write("(")
		OutputExpressionList(parameters)
		Output.Write(")")

	protected override def OutputExpressionList(exps as CodeExpressionCollection):
		if exps is null or exps.Count == 0:
			return
		total = exps.Count
		i = 0
		while i < total:
			e as CodeExpression = exps[i]
			if AsBool(e.UserData["Explode"]):
				Output.Write("*")
			GenerateExpression(e)
			if i < total-1:
				Output.Write(", ")
			++i

	def passcheck(stuff as ICollection):
		return if stuff.IsValid()
		if not AsBool(Options["WhiteSpaceAgnostic"]):
			Output.WriteLine("pass")

	override def OutputTypeNamePair(type as CodeTypeReference, name as string):
		Output.Write("${name} as ")
		OutputType(type)

	protected override def GenerateParameterDeclarationExpression(e as CodeParameterDeclarationExpression):
		name = e.Name
		if e.Type.ArrayElementType:
			paramarray as CodeAttributeDeclaration = null
			for att as CodeAttributeDeclaration in e.CustomAttributes:
				if att.Name.EndsWith("ParamArrayAttribute") or att.Name.EndsWith("ParamArray"):
					paramarray = att
					break
			if paramarray:
				e.CustomAttributes.Remove(paramarray)
				name = "*"+e.Name

		OutputAttributes(e.CustomAttributes, null, true)
		OutputDirection(e.Direction)
		OutputTypeNamePair(e.Type, name)

	private def OutputAttributes(attributes as CodeAttributeDeclarationCollection, prefix as string, inline as bool):
		for att as CodeAttributeDeclaration in attributes:
			GenerateAttributeDeclarationsStart(attributes)
			Output.Write(prefix) if prefix
			OutputAttributeDeclaration(att)
			GenerateAttributeDeclarationsEnd(attributes)
			if inline:  //for parameter and return type attributes
				pass //Output.Write(" ")
			else:
				Output.WriteLine()

	private def OutputAttributeDeclaration(attribute as CodeAttributeDeclaration):
		Output.Write(attribute.Name.Replace ('+', '.'))
		Output.Write('(')
		first = true
		for argument as CodeAttributeArgument in attribute.Arguments:
			if first:
				OutputAttributeArgument(argument)
				first = false
			else:
				Output.Write(", ")
				OutputAttributeArgument(argument)
		Output.Write(')')

	def ModifiersAndAttributes(typeMember as CodeTypeMember):
		if typeMember.CustomAttributes:
			OutputAttributes(typeMember.CustomAttributes, null, false)

		//FIXME: We just ignore "new" methods, since they are unsupported in boo
		if typeMember.Attributes & MemberAttributes.VTableMask == MemberAttributes.New:
			typeMember.Attributes &= cast(MemberAttributes,~cast(int,MemberAttributes.New))

		//TODO: Override these.  Right now we are lucky C# and boo are the same
		//with respect to keywords and defaults (such as final/sealed by default).
		//We should override for example to not print out "public" since it is boo default.
		OutputMemberAccessModifier(typeMember.Attributes)
		OutputMemberScopeModifier(typeMember.Attributes)

	def OutputAttributeArgument(arg as CodeAttributeArgument):
		if arg.Name and arg.Name != "":
			Output.Write(arg.Name)
			Output.Write(":")
		GenerateExpression(arg.Value)

	protected override def OutputDirection(direction as FieldDirection):
		if direction == FieldDirection.Ref or direction == FieldDirection.Out:
			Output.Write("ref ")

	protected override def OutputFieldScopeModifier(attributes as MemberAttributes):
		scope = attributes & MemberAttributes.ScopeMask
		if scope == MemberAttributes.Static:
			Output.Write("static ")
		elif scope == MemberAttributes.Const:
			Output.Write("static final ")

	private def AsBool(data):
		return data is not null and data isa bool and cast(bool,data)

	protected override def GenerateCompileUnitStart(compileUnit as CodeCompileUnit):
		GenerateComment(CodeComment("------------------------------------------------------------------------------"))
		GenerateComment(CodeComment("This code was automatically generated by Boo.Lang.CodeDom v.${BooVersion}."))
		GenerateComment(CodeComment(""))
		GenerateComment(CodeComment("     Changes to this file may cause incorrect behavior and will be lost if "))
		GenerateComment(CodeComment("     the code is regenerated."))
		GenerateComment(CodeComment("------------------------------------------------------------------------------"))
		Output.WriteLine()

		//for future:
		if AsBool(Options["WhiteSpaceAgnostic"]):
			Output.WriteLine("//option WhiteSpaceAgnostic")
			Output.WriteLine()

		super.GenerateCompileUnitStart(compileUnit)

	protected override def GenerateCompileUnit(compileUnit as CodeCompileUnit):
		GenerateCompileUnitStart(compileUnit)

		for ns as CodeNamespace in compileUnit.Namespaces:
			GenerateNamespace(ns)

		if compileUnit.AssemblyCustomAttributes.Count > 0:
			OutputAttributes(compileUnit.AssemblyCustomAttributes,
					"assembly:", false)
			Output.WriteLine("")

		GenerateCompileUnitEnd(compileUnit)

	protected virtual def BeginBlock():
		Output.WriteLine(":")
		++Indent

	protected virtual def EndBlock():
		EndBlock(true)

	protected virtual def EndBlock(realend as bool):
		--Indent
		if realend:
			End()

	protected virtual def End():
		if AsBool(Options["WhiteSpaceAgnostic"]):
			Output.WriteLine("end")

#region FixIndent
	static newlinePattern = Regex("\\n",RegexOptions.Compiled)
	static whiteSpacePattern = Regex("(\\s*)",RegexOptions.Compiled)

	static public def FixIndent(code as string, indentstring as string,
				indentlevel as int, indentfirst as bool) as string:
		//how much the code should be indented:
		if indentlevel > 0:
			indentprefix = indentstring * indentlevel
			nonEmptyPrefix = (indentprefix != string.Empty)
		else:
			indentprefix = string.Empty
			nonEmptyPrefix = false

		if code is null or code==string.Empty:
			if indentfirst:
				return indentprefix
			else:
				return string.Empty

		lines = newlinePattern.Split(code.Replace("\r\n","\n"))

		foundFirstCodeLine = false //first line of real code
		insidecomment = 0 //inside /* */
		insidestring = false  //inside """ """
		firstline = true
		buffer = System.Text.StringBuilder()
		indent = ""
		indentSize = 0
		toTabs = indentprefix.StartsWith("\t") //otherwise, assume spaces
		for line in lines:
			//ignore comments before the first line of real code
			if not foundFirstCodeLine:
				trimmed = line.Trim()
				startmultiline = trimmed.StartsWith("/*")

				//if not whitespace and not a comment...
				if (insidecomment <= 0 and
						not startmultiline and
						not trimmed == string.Empty and
						not trimmed.StartsWith("#") and
						not trimmed.StartsWith("//")):
					foundFirstCodeLine = true
					indent = whiteSpacePattern.Match(line).Groups[0].Value
					indentSize = len(indent)
					insidecomment = 0

				//special stuff for handling multiline comments before code
				if startmultiline or insidecomment > 0:
					j = 0
					linelen = len(trimmed) - 1
					while j < linelen:
						rawArrayIndexing:
							c = trimmed[j]
						if c==char('/'):
							rawArrayIndexing:
								nextc = trimmed[j+1]
							if nextc==char('*'):
								++insidecomment
								++j
						elif c==char('*') and insidecomment > 0:
							rawArrayIndexing:
								nextc = trimmed[j+1]
							if nextc==char('/'):
								--insidecomment
								++j
						++j

			if not foundFirstCodeLine or not insidestring:
				if firstline:
					firstline = false
					if indentfirst and nonEmptyPrefix:
						buffer.Append(indentprefix)
				else:
					if nonEmptyPrefix:
						buffer.Append(indentprefix)

				if not foundFirstCodeLine:
					buffer.Append(line + System.Environment.NewLine)
					continue

				if line.StartsWith(indent):
					if indentSize > 0:
						rest = line[indentSize:]
					else:
						rest = line
					if len(rest) > 0:
						//convert any more leading whitespace to tabs or spaces
						//so we don't mix tabs and spaces on same line
						ws = whiteSpacePattern.Match(rest).Groups[0].Value
						sz = len(ws)
						if len(ws):
							rawArrayIndexing:
								c = rest[0]
							if toTabs:
								if c==char(' '):
									rest = rest[sz:]
									ws = ws.Replace("    ","\t")
									ws = ws.Replace("   ","\t")
									ws = ws.Replace("  ","\t")
									ws = ws.Replace(" ","\t")
									buffer.Append(ws)
							else:
								if c==char('\t'):
									rest = rest[sz:]
									ws = ws.Replace("\t","    ")
									buffer.Append(ws)
						buffer.Append(rest)
				else: //line is not indented as expected, pass it on as is:
					buffer.Append(line)
			else: //we are inside a triple quoted string:
				buffer.Append(line)

			buffer.Append(System.Environment.NewLine)

			//scan for triple quoted string literals:
			//   for speed reasons, I'm not also checking for insidecomment,
			//   so if you have an odd # of triple quotes inside a comment,
			//   you can break this.
			j = 0
			linelen = len(line) - 2
			while j < linelen:
				rawArrayIndexing:
					c1 = line[j]
				if c1==char('"'):
					rawArrayIndexing:
						c2 = line[j+1]
					if c2==char('"'):
						rawArrayIndexing:
							c3 = line[j+2]
						if c3==char('"'):
							insidestring = not insidestring
							j += 2
				++j

		return buffer.ToString()
#endregion

#region license
// Copyright (c) 2004, Rodrigo B. de Oliveira (rbo@acm.org)
// All rights reserved.
//
// Redistribution and use in source and binary forms, with or without modification,
// are permitted provided that the following conditions are met:
//
//     * Redistributions of source code must retain the above copyright notice,
//     this list of conditions and the following disclaimer.
//     * Redistributions in binary form must reproduce the above copyright notice,
//     this list of conditions and the following disclaimer in the documentation
//     and/or other materials provided with the distribution.
//     * Neither the name of Rodrigo B. de Oliveira nor the names of its
//     contributors may be used to endorse or promote products derived from this
//     software without specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
// ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
// WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
// DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE
// FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
// DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
// SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
// CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
// OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
// THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
#endregion

// authors:
// Arron Washington
// Ian MacLean (original C# version)

//See also:
//http://svn.myrealbox.com/viewcvs/trunk/mcs/class/System/Microsoft.CSharp/CSharpCodeGenerator.cs?view=auto
//http://svn.myrealbox.com/viewcvs/trunk/mcs/class/System/Microsoft.VisualBasic/VBCodeGenerator.cs?view=auto

namespace Boo.Lang.CodeDom

import System
import System.CodeDom
import System.CodeDom.Compiler
import System.IO
import System.Reflection
import System.Collections
import System.Text.RegularExpressions
import System.Globalization

class BooCodeGenerator(CodeGenerator):
	static _NET_2_0 as bool = System.Environment.Version >= System.Version(2, 0)

	static primitives = { "System.Double" : "double",
						"System.Single" : "single",
						"System.Int32" : "int",
						"System.Int64" : "long",
						"System.Int16" : "short",
						"System.UInt16" : "ushort",
						"System.Boolean" : "bool",
						"System.Char" : "char",
						"System.String" : "string",
						"System.Object" : "object",
						"System.Void" : "void"}

	protected NullToken as string:
		get:
			return "null"

	protected override def OutputType(typeRef as CodeTypeReference):
		Output.Write(GetTypeOutput(typeRef))

	protected override def GenerateArrayCreateExpression(exp as CodeArrayCreateExpression) :
		if exp.Initializers is not null and exp.Size == 0 and exp.SizeExpression is null:
			Output.Write("(")
			if exp.CreateType is not null:
				Output.Write("of ")
				OutputType(exp.CreateType)
				Output.Write(": ")
			OutputExpressionList(exp.Initializers)
			//no trailing comma needed for single item with "of" type
			if exp.Initializers.Count==0 or (exp.Initializers.Count==1 and not exp.CreateType):
				Output.Write(",")
			Output.Write(")")
		else:
			Output.Write("array(")
			OutputType(exp.CreateType)
			Output.Write(", ")
			if exp.SizeExpression is not null:
				GenerateExpression(exp.SizeExpression)
			else:
				Output.Write(exp.Size)
			Output.Write(")")

	protected override def GenerateBaseReferenceExpression(e as CodeBaseReferenceExpression) :
		Output.Write("super")

	protected override def GenerateCastExpression(e as CodeCastExpression) :
		Output.Write("cast(")
		OutputType(e.TargetType)
		Output.Write(",")
		GenerateExpression(e.Expression)
		Output.Write(")")

	protected override def GenerateDelegateCreateExpression(e as CodeDelegateCreateExpression) :
		GenerateExpression(e.TargetObject)
		Output.Write(".${e.MethodName} as ")
		OutputType(e.DelegateType)

	protected override def GenerateFieldReferenceExpression(e as CodeFieldReferenceExpression):
		MemberReference(e.TargetObject, e.FieldName)

	protected override def GenerateArgumentReferenceExpression(e as CodeArgumentReferenceExpression) :
		Output.Write(e.ParameterName)

	protected override def GenerateVariableReferenceExpression(e as CodeVariableReferenceExpression) :
		Output.Write(e.VariableName)

	protected override def GenerateIndexerExpression(e as CodeIndexerExpression) :
		Indexer(e.TargetObject, e.Indices)

	protected override def GenerateArrayIndexerExpression(e as CodeArrayIndexerExpression) :
		Indexer(e.TargetObject, e.Indices)

	protected override def GenerateMethodInvokeExpression(e as CodeMethodInvokeExpression) :
		Invocation(e.Method, e.Parameters)

	protected override def GenerateMethodReferenceExpression(e as CodeMethodReferenceExpression) :
		MemberReference(e.TargetObject, e.MethodName)
	protected override def GenerateEventReferenceExpression(e as CodeEventReferenceExpression) :
		MemberReference(e.TargetObject, e.EventName)

	protected override def GenerateDelegateInvokeExpression(e as CodeDelegateInvokeExpression) :
		Invocation(e.TargetObject, e.Parameters)

	protected override def GenerateObjectCreateExpression(e as CodeObjectCreateExpression) :
		OutputType(e.CreateType)
		Output.Write("(")
		OutputExpressionList(e.Parameters)
		Output.Write(")")

	protected override def GeneratePropertyReferenceExpression(e as CodePropertyReferenceExpression) :
		MemberReference(e.TargetObject, e.PropertyName)

	protected override def GeneratePropertySetValueReferenceExpression(e as CodePropertySetValueReferenceExpression) :
		Output.Write("value")

	protected override def GenerateThisReferenceExpression(e as CodeThisReferenceExpression) :
		Output.Write("self")

	protected override def GenerateExpressionStatement(e as CodeExpressionStatement) :
		GenerateExpression(e.Expression)
		Output.WriteLine()

	protected override def GenerateIterationStatement(e as CodeIterationStatement):
		if e.InitStatement:
			GenerateStatement(e.InitStatement)
		Output.Write("while ")
		GenerateExpression(e.TestExpression)
		BeginBlock()
		if e.Statements and e.Statements.IsValid():
			GenerateStatements(e.Statements)
		if e.IncrementStatement:
			GenerateStatement(e.IncrementStatement)
		else:
			passcheck(e.Statements)
		EndBlock()

	protected override def GenerateThrowExceptionStatement(e as CodeThrowExceptionStatement) :
		Output.Write("raise ")
		GenerateExpression(e.ToThrow)
		Output.WriteLine()

	protected override def GenerateComment(comment as CodeComment) :
		//TODO: check comment.DocComment when boo doc format is available
		commentSymbol = "#"
		txt = comment.Text

		Output.Write(commentSymbol + " ")

		i = 0
		while i<len(txt):
			rawArrayIndexing:
				Output.Write(txt[i])
				if txt[i] == char('\r'):
					if i<len(txt)-1 and txt[i+1]==char('\n'):
						continue
					Output.Write(commentSymbol)
				elif txt[i] == char('\n'):
					Output.Write(commentSymbol)
			++i
		Output.WriteLine()

	protected override def GenerateMethodReturnStatement(e as CodeMethodReturnStatement) :
		Output.Write("return ")
		GenerateExpression(e.Expression)
		Output.WriteLine()

	protected override def GenerateConditionStatement(e as CodeConditionStatement) :
		Output.Write("if ")
		GenerateExpression(e.Condition)
		BeginBlock()
		GenerateStatements(e.TrueStatements)
		passcheck(e.TrueStatements)
		EndBlock(false)
		if e.FalseStatements and e.FalseStatements.IsValid():
			Output.Write("else")
			BeginBlock()
			GenerateStatements(e.FalseStatements)
			passcheck(e.FalseStatements)
			EndBlock(false)
		End()

	protected override def GenerateTryCatchFinallyStatement(e as CodeTryCatchFinallyStatement) :
		Output.Write("try")
		BeginBlock()
		GenerateStatements(e.TryStatements)
		passcheck(e.TryStatements)
		EndBlock(false)
		for exp as CodeCatchClause in e.CatchClauses:
			Output.Write("except ")
			Output.Write("${exp.LocalName} as ")
			OutputType(exp.CatchExceptionType)
			BeginBlock()
			GenerateStatements(exp.Statements)
			passcheck(exp.Statements)
			EndBlock(false)

		if e.FinallyStatements and e.FinallyStatements.Count > 0:
			Output.Write("ensure")
			BeginBlock()
			GenerateStatements(e.FinallyStatements)
			passcheck(e.FinallyStatements)
			EndBlock(false)
		End()

	protected override def GenerateAssignStatement(e as CodeAssignStatement) :
		GenerateExpression(e.Left)
		Output.Write(" = ")
		GenerateExpression(e.Right)
		Output.WriteLine()
	protected override def GenerateAttachEventStatement(e as CodeAttachEventStatement) :
		GenerateExpression(e.Event)
		Output.Write(" += ")
		GenerateExpression(e.Listener)
		Output.WriteLine()
	protected override def GenerateRemoveEventStatement(e as CodeRemoveEventStatement) :
		GenerateExpression(e.Event)
		Output.Write(" -= ")
		GenerateExpression(e.Listener)
		Output.WriteLine()
	protected override def GenerateGotoStatement(e as CodeGotoStatement) :
		Output.WriteLine("goto ${e.Label}")
	protected override def GenerateLabeledStatement(e as CodeLabeledStatement) :
		Output.WriteLine(":${e.Label}")
		if e.Statement:
			GenerateStatement(e.Statement)
	protected override def GenerateVariableDeclarationStatement(e as CodeVariableDeclarationStatement) :
		Output.Write("${e.Name} as ")
		OutputType(e.Type)
		if e.InitExpression:
			Output.Write(" = ")
			GenerateExpression(e.InitExpression)
		Output.WriteLine()
	protected override def GenerateLinePragmaStart(e as CodeLinePragma) :
		pass

	protected override def GenerateLinePragmaEnd(e as CodeLinePragma) :
		pass

	protected override def GenerateEvent(e as CodeMemberEvent, c as CodeTypeDeclaration) :

		if e.PrivateImplementationType:
			raise "Does not support private implementation type."
		if e.ImplementationTypes.IsValid():
			raise "Does not implement these types: ${join(e.ImplementationTypes)}"
		e.Attributes |= MemberAttributes.Final

		ModifiersAndAttributes(e)

		Output.Write("event ${e.Name} as ")
		OutputType(e.Type)
		Output.WriteLine()
	protected override def GenerateField(e as CodeMemberField) :

		ModifiersAndAttributes(e)
		Output.Write("${e.Name} as ")
		OutputType(e.Type)
		if e.InitExpression:
			Output.Write(" = ")
			GenerateExpression(e.InitExpression)
		Output.WriteLine()

	protected override def GenerateSnippetMember(e as CodeSnippetTypeMember) :
		if e.CustomAttributes:
			OutputAttributes(e.CustomAttributes, null, false)
		Output.WriteLine(FixIndent(e.Text, Options.IndentString, Indent, false))

	protected override def GenerateSnippetExpression(e as CodeSnippetExpression) :
		//Output.Write("("+e.Value+")")
		Output.Write(e.Value)

	protected override def GenerateSnippetCompileUnit(e as CodeSnippetCompileUnit) :
		Output.WriteLine(FixIndent(e.Value, Options.IndentString, Indent, false))

	protected override def GenerateSnippetStatement(e as CodeSnippetStatement) :
		if _NET_2_0:
			Output.WriteLine(e.Value)
		else:
			Output.WriteLine(FixIndent(e.Value, Options.IndentString, Indent, false))

	protected override def GenerateEntryPointMethod(e as CodeEntryPointMethod, c as CodeTypeDeclaration) :
		Method(e, "Main")

	protected override def GenerateMethod(e as CodeMemberMethod, c as CodeTypeDeclaration) :
		Method(e, e.Name)

	protected override def GenerateProperty(e as CodeMemberProperty, c as CodeTypeDeclaration) :
		ModifiersAndAttributes(e)

		if (e.Parameters.Count > 0
			and string.Compare(e.Name, "Item", true, CultureInfo.InvariantCulture) == 0):
			Output.Write(" self")
		else:
			Output.Write(" ${e.Name}")
		if len(e.Parameters) > 0:
			Output.Write("[")
			OutputParameters(e.Parameters)
			Output.Write("]")
		Output.Write(" as ")
		OutputType(e.Type)
		BeginBlock()
		if e.HasGet:
			Output.Write("get")
			BeginBlock()
			GenerateStatements(e.GetStatements)
			passcheck(e.GetStatements)
			EndBlock() //TODO: Change to EndBlock(false) when BOO-631 accepted
		if e.HasSet:
			Output.Write("set")
			BeginBlock()
			GenerateStatements(e.SetStatements)
			passcheck(e.SetStatements)
			EndBlock() //TODO: Change to EndBlock(false) when BOO-631 accepted
		EndBlock()

	protected override def GenerateConstructor(e as CodeConstructor, c as CodeTypeDeclaration) :
		e.Attributes |= MemberAttributes.Final
		Method(e, "constructor")

	protected override def GenerateTypeConstructor(e as CodeTypeConstructor) :
		e.Attributes |= MemberAttributes.Static
		e.Attributes |= MemberAttributes.Public
		e.Parameters.Clear()
		Method(e, "constructor")

	protected override def GenerateTypeStart(e as CodeTypeDeclaration):
		if e.CustomAttributes:
			OutputAttributes(e.CustomAttributes, null, false)
		if e isa CodeTypeDelegate:
			GenerateDelegate(e)
			return

		//TODO: move this to an override of OutputTypeAttributes

		//FIXME: When boo gets preprocessor directives, i.e. #if NET_2_0
		//Til then we have to partially rely on super.OutputTypeAttributes

		//output "final", since super.OutputTypeAttributes outputs "sealed"
		if e.TypeAttributes & TypeAttributes.Sealed == TypeAttributes.Sealed:
			Output.Write("final ")

			//remove sealed from attributes:

			//FIXME: when boo enum processing fixed
			//e.TypeAttributes &= ~TypeAttributes.Sealed
			e.TypeAttributes &= cast(TypeAttributes,~cast(int,TypeAttributes.Sealed))

		visibility = e.TypeAttributes & TypeAttributes.VisibilityMask
		if visibility == TypeAttributes.Public or visibility == TypeAttributes.NestedPublic:
			pass //Output.Write("public ") //public by default
		elif visibility == TypeAttributes.NestedPrivate:
			Output.Write("private ")
		elif (visibility == TypeAttributes.NotPublic or
			TypeAttributes.NestedFamANDAssem or
			TypeAttributes.NestedAssembly):
			Output.Write("internal ")
		elif visibility == TypeAttributes.NestedFamily:
			//FIXME: BOO-666
			Output.Write("protected ")
		elif visibility == TypeAttributes.NestedFamORAssem:
			//FIXME: BOO-666
			Output.Write("internal ")

		//super OutputTypeAttributes ignores TypeAttributes.NotPublic (internal)
		//FIXME: when boo enum processing fixed
		//e.TypeAttributes &= ~TypeAttributes.VisibilityMask
		e.TypeAttributes &= cast(TypeAttributes,~cast(int,TypeAttributes.VisibilityMask))
		e.TypeAttributes |= TypeAttributes.NotPublic //not really nec. since val is 0

		//TODO: Remove call to OutputTypeAttributes
		OutputTypeAttributes(e.TypeAttributes, e.IsStruct, e.IsEnum)
		/////////////////////////////////////

		Output.Write("${e.Name}(")
		for index in range(len(e.BaseTypes)):
			var as CodeTypeReference = e.BaseTypes[index]
			OutputType(var)
			continue unless index + 1 != e.BaseTypes.Count
			Output.Write(",")
		Output.Write(")")
		BeginBlock()
		#Ah hah hah, yeah, no. Empty class.
		passcheck(e.Members)

	private def GenerateDelegate(e as CodeTypeDelegate):
		if e.TypeAttributes & TypeAttributes.Sealed == TypeAttributes.Sealed:
			Output.Write("final ")
		if e.TypeAttributes & TypeAttributes.NestedFamORAssem == TypeAttributes.Public:
			Output.Write("public ")
		Output.Write("callable ${e.Name}(")
		OutputParameters(e.Parameters)
		Output.Write(") as ")
		OutputType(e.ReturnType)

	protected override def GenerateTypeEnd(e as CodeTypeDeclaration) :
		EndBlock()

	protected override def GenerateNamespaceStart(e as CodeNamespace) :
		if e and e.Name and e.Name != string.Empty:
			Output.WriteLine("namespace ${e.Name}")

	protected override def GenerateNamespaceEnd(e as CodeNamespace) :
		pass

	protected override def GenerateNamespaceImport(e as CodeNamespaceImport) :
		Output.WriteLine("import ${e.Namespace}")

	protected override def GenerateAttributeDeclarationsStart(attributes as CodeAttributeDeclarationCollection) :
		Output.Write("[")

	protected override def GenerateAttributeDeclarationsEnd(attributes as CodeAttributeDeclarationCollection) :
		Output.Write("]")

	protected override def Supports(support as GeneratorSupport) as bool:
		return true

	protected override def IsValidIdentifier(value as string) as bool:
		return true

	protected override def CreateEscapedIdentifier(value as string) as string:
		return value

	protected override def CreateValidIdentifier(value as string) as string:
		return value

	protected override def GetTypeOutput(typeRef as CodeTypeReference) as string:
		if typeRef.ArrayElementType:
			out = GetTypeOutput(typeRef.ArrayElementType)
		elif typeRef.BaseType in primitives:
			out = primitives[typeRef.BaseType]
		else:
			out = typeRef.BaseType

		if typeRef.ArrayRank == 0:
			return out
		elif typeRef.ArrayRank == 1:
			return "(${out})"
		else:
			return "(${out}, ${typeRef.ArrayRank})"

	protected override def QuoteSnippetString(snippet as string) as string:
		s = snippet.Replace("\\", "\\\\")
		s = s.Replace("\"", "\\\"")
		s = s.Replace("\t", "\\t")
		s = s.Replace("\r", "\\r")
		s = s.Replace("\n", "\\n")
		return "\"" + s + "\""

	def Method(method as duck, name as string):
		ModifiersAndAttributes(method)
		Output.Write("def ${name}(")
		OutputParameters(method.Parameters)
		Output.Write(")")
		unless GetTypeOutput(method.ReturnType) == "void":
			Output.Write(" as ")
			OutputType(method.ReturnType)
		if method.ReturnTypeCustomAttributes:
			OutputAttributes(method.ReturnTypeCustomAttributes, null, true)
		BeginBlock()
		ctor = method as CodeConstructor
		do_pass = true
		if ctor:
			if ctor.BaseConstructorArgs.IsValid():
				Output.Write("super(")
				OutputExpressionList(ctor.BaseConstructorArgs)
				Output.WriteLine(")")
				do_pass = false
			if ctor.ChainedConstructorArgs.IsValid():
				Output.Write("self(")
				OutputExpressionList(ctor.ChainedConstructorArgs)
				Output.WriteLine(")")
				do_pass = false
		GenerateStatements(method.Statements)
		if do_pass:
			passcheck(method.Statements)
		EndBlock()

	def MemberReference(target as CodeExpression, member as string):
		if target: #target.method( ... )
			GenerateExpression(target)
			Output.Write(".${member}")
		else: #method( ... )
			Output.Write(member)

	def Indexer(target as CodeExpression, indices as CodeExpressionCollection):
		GenerateExpression(target)
		Output.Write("[")
		OutputExpressionList(indices)
		Output.Write("]")

	def Invocation(target as CodeExpression, parameters as CodeExpressionCollection):
		GenerateExpression(target)
		Output.Write("(")
		OutputExpressionList(parameters)
		Output.Write(")")

	protected override def OutputExpressionList(exps as CodeExpressionCollection):
		if exps is null or exps.Count == 0:
			return
		total = exps.Count
		i = 0
		while i < total:
			e as CodeExpression = exps[i]
			if AsBool(e.UserData["Explode"]):
				Output.Write("*")
			GenerateExpression(e)
			if i < total-1:
				Output.Write(", ")
			++i

	def passcheck(stuff as ICollection):
		return if stuff.IsValid()
		if not AsBool(Options["WhiteSpaceAgnostic"]):
			Output.WriteLine("pass")

	override def OutputTypeNamePair(type as CodeTypeReference, name as string):
		Output.Write("${name} as ")
		OutputType(type)

	protected override def GenerateParameterDeclarationExpression(e as CodeParameterDeclarationExpression):
		name = e.Name
		if e.Type.ArrayElementType:
			paramarray as CodeAttributeDeclaration = null
			for att as CodeAttributeDeclaration in e.CustomAttributes:
				if att.Name.EndsWith("ParamArrayAttribute") or att.Name.EndsWith("ParamArray"):
					paramarray = att
					break
			if paramarray:
				e.CustomAttributes.Remove(paramarray)
				name = "*"+e.Name

		OutputAttributes(e.CustomAttributes, null, true)
		OutputDirection(e.Direction)
		OutputTypeNamePair(e.Type, name)

	private def OutputAttributes(attributes as CodeAttributeDeclarationCollection, prefix as string, inline as bool):
		for att as CodeAttributeDeclaration in attributes:
			GenerateAttributeDeclarationsStart(attributes)
			Output.Write(prefix) if prefix
			OutputAttributeDeclaration(att)
			GenerateAttributeDeclarationsEnd(attributes)
			if inline:  //for parameter and return type attributes
				pass //Output.Write(" ")
			else:
				Output.WriteLine()

	private def OutputAttributeDeclaration(attribute as CodeAttributeDeclaration):
		Output.Write(attribute.Name.Replace ('+', '.'))
		Output.Write('(')
		first = true
		for argument as CodeAttributeArgument in attribute.Arguments:
			if first:
				OutputAttributeArgument(argument)
				first = false
			else:
				Output.Write(", ")
				OutputAttributeArgument(argument)
		Output.Write(')')

	def ModifiersAndAttributes(typeMember as CodeTypeMember):
		if typeMember.CustomAttributes:
			OutputAttributes(typeMember.CustomAttributes, null, false)

		//FIXME: We just ignore "new" methods, since they are unsupported in boo
		if typeMember.Attributes & MemberAttributes.VTableMask == MemberAttributes.New:
			typeMember.Attributes &= cast(MemberAttributes,~cast(int,MemberAttributes.New))

		//TODO: Override these.  Right now we are lucky C# and boo are the same
		//with respect to keywords and defaults (such as final/sealed by default).
		//We should override for example to not print out "public" since it is boo default.
		OutputMemberAccessModifier(typeMember.Attributes)
		OutputMemberScopeModifier(typeMember.Attributes)

	def OutputAttributeArgument(arg as CodeAttributeArgument):
		if arg.Name and arg.Name != "":
			Output.Write(arg.Name)
			Output.Write(":")
		GenerateExpression(arg.Value)

	protected override def OutputDirection(direction as FieldDirection):
		if direction == FieldDirection.Ref or direction == FieldDirection.Out:
			Output.Write("ref ")

	protected override def OutputFieldScopeModifier(attributes as MemberAttributes):
		scope = attributes & MemberAttributes.ScopeMask
		if scope == MemberAttributes.Static:
			Output.Write("static ")
		elif scope == MemberAttributes.Const:
			Output.Write("static final ")

	private def AsBool(data):
		return data is not null and data isa bool and cast(bool,data)

	protected override def GenerateCompileUnitStart(compileUnit as CodeCompileUnit):
		GenerateComment(CodeComment("------------------------------------------------------------------------------"))
		GenerateComment(CodeComment("This code was automatically generated by Boo.Lang.CodeDom v.${BooVersion}."))
		GenerateComment(CodeComment(""))
		GenerateComment(CodeComment("     Changes to this file may cause incorrect behavior and will be lost if "))
		GenerateComment(CodeComment("     the code is regenerated."))
		GenerateComment(CodeComment("------------------------------------------------------------------------------"))
		Output.WriteLine()

		//for future:
		if AsBool(Options["WhiteSpaceAgnostic"]):
			Output.WriteLine("//option WhiteSpaceAgnostic")
			Output.WriteLine()

		super.GenerateCompileUnitStart(compileUnit)

	protected override def GenerateCompileUnit(compileUnit as CodeCompileUnit):
		GenerateCompileUnitStart(compileUnit)

		for ns as CodeNamespace in compileUnit.Namespaces:
			GenerateNamespace(ns)

		if compileUnit.AssemblyCustomAttributes.Count > 0:
			OutputAttributes(compileUnit.AssemblyCustomAttributes,
					"assembly:", false)
			Output.WriteLine("")

		GenerateCompileUnitEnd(compileUnit)

	protected virtual def BeginBlock():
		Output.WriteLine(":")
		++Indent

	protected virtual def EndBlock():
		EndBlock(true)

	protected virtual def EndBlock(realend as bool):
		--Indent
		if realend:
			End()

	protected virtual def End():
		if AsBool(Options["WhiteSpaceAgnostic"]):
			Output.WriteLine("end")

#region FixIndent
	static newlinePattern = Regex("\\n",RegexOptions.Compiled)
	static whiteSpacePattern = Regex("(\\s*)",RegexOptions.Compiled)

	static public def FixIndent(code as string, indentstring as string,
				indentlevel as int, indentfirst as bool) as string:
		//how much the code should be indented:
		if indentlevel > 0:
			indentprefix = indentstring * indentlevel
			nonEmptyPrefix = (indentprefix != string.Empty)
		else:
			indentprefix = string.Empty
			nonEmptyPrefix = false

		if code is null or code==string.Empty:
			if indentfirst:
				return indentprefix
			else:
				return string.Empty

		lines = newlinePattern.Split(code.Replace("\r\n","\n"))

		foundFirstCodeLine = false //first line of real code
		insidecomment = 0 //inside /* */
		insidestring = false  //inside """ """
		firstline = true
		buffer = System.Text.StringBuilder()
		indent = ""
		indentSize = 0
		toTabs = indentprefix.StartsWith("\t") //otherwise, assume spaces
		for line in lines:
			//ignore comments before the first line of real code
			if not foundFirstCodeLine:
				trimmed = line.Trim()
				startmultiline = trimmed.StartsWith("/*")

				//if not whitespace and not a comment...
				if (insidecomment <= 0 and
						not startmultiline and
						not trimmed == string.Empty and
						not trimmed.StartsWith("#") and
						not trimmed.StartsWith("//")):
					foundFirstCodeLine = true
					indent = whiteSpacePattern.Match(line).Groups[0].Value
					indentSize = len(indent)
					insidecomment = 0

				//special stuff for handling multiline comments before code
				if startmultiline or insidecomment > 0:
					j = 0
					linelen = len(trimmed) - 1
					while j < linelen:
						rawArrayIndexing:
							c = trimmed[j]
						if c==char('/'):
							rawArrayIndexing:
								nextc = trimmed[j+1]
							if nextc==char('*'):
								++insidecomment
								++j
						elif c==char('*') and insidecomment > 0:
							rawArrayIndexing:
								nextc = trimmed[j+1]
							if nextc==char('/'):
								--insidecomment
								++j
						++j

			if not foundFirstCodeLine or not insidestring:
				if firstline:
					firstline = false
					if indentfirst and nonEmptyPrefix:
						buffer.Append(indentprefix)
				else:
					if nonEmptyPrefix:
						buffer.Append(indentprefix)

				if not foundFirstCodeLine:
					buffer.Append(line + System.Environment.NewLine)
					continue

				if line.StartsWith(indent):
					if indentSize > 0:
						rest = line[indentSize:]
					else:
						rest = line
					if len(rest) > 0:
						//convert any more leading whitespace to tabs or spaces
						//so we don't mix tabs and spaces on same line
						ws = whiteSpacePattern.Match(rest).Groups[0].Value
						sz = len(ws)
						if len(ws):
							rawArrayIndexing:
								c = rest[0]
							if toTabs:
								if c==char(' '):
									rest = rest[sz:]
									ws = ws.Replace("    ","\t")
									ws = ws.Replace("   ","\t")
									ws = ws.Replace("  ","\t")
									ws = ws.Replace(" ","\t")
									buffer.Append(ws)
							else:
								if c==char('\t'):
									rest = rest[sz:]
									ws = ws.Replace("\t","    ")
									buffer.Append(ws)
						buffer.Append(rest)
				else: //line is not indented as expected, pass it on as is:
					buffer.Append(line)
			else: //we are inside a triple quoted string:
				buffer.Append(line)

			buffer.Append(System.Environment.NewLine)

			//scan for triple quoted string literals:
			//   for speed reasons, I'm not also checking for insidecomment,
			//   so if you have an odd # of triple quotes inside a comment,
			//   you can break this.
			j = 0
			linelen = len(line) - 2
			while j < linelen:
				rawArrayIndexing:
					c1 = line[j]
				if c1==char('"'):
					rawArrayIndexing:
						c2 = line[j+1]
					if c2==char('"'):
						rawArrayIndexing:
							c3 = line[j+2]
						if c3==char('"'):
							insidestring = not insidestring
							j += 2
				++j

		return buffer.ToString()
#endregion