refactor terminal, xterm; +keycodes, mouse support

- Refactor Terminal Class.
    - Add terminal support for Control+Alt+Key & Shift+Alt+Key sequences.
    - Modularize the Byte reading loop. Make structure simpler and clearer.
    - Move key-code structures to keyCodes Class.
    - Show relevant info when catching error related to issue #1.
    - Add initial mouse support.
    - Temporarily made public some properties and methods for easy interop.
- Rename ANSI class to XTerm.
- Rename ansi.dart file to xterm_control.dart
- Add keyCodes Class in xterm_keycodes.dart.
- Rename CLI --terminal-type ansi argument to xterm.
- New word: KEY
- Modify InputQueue & VirtualMachine classes.
    - Implemented a single character input buffer for the word KEY
    - Rename VirtualMachine.source property to input.
    - Rename InputQueue properties: id to sourceId & length to sourceLength.
    - Rename getLineFromSimpleTerminal() to getLineFromXTerm().
    - Enable XTerm by default only in Linux and MacOs
- ForthError.unmanaged() text update. Update error tests.
- Minor fixes.
- More comments.
- Update readme.

README.md

@@ -62,8 +62,6 @@ You'll first need to install the appropriate version of [Dart](https://www.dartl
 	pub global activate --source path ./
 	```
 
-*Read more about [pub global](https://www.dartlang.org/tools/pub/cmd/pub-global.html) & [script snapshots](https://www.dartlang.org/articles/snapshots/#how-to-generate-and-use-script-snapshots).*
-
 ### Command Line Interface
 
 **Usage Examples**

bin/common/forandar.dart

@@ -97,7 +97,7 @@ void argParser(List<String> args, Configuration c, InputQueue i) {
 			allowMultiple: false,
 			valueHelp: 'LINES',
 			callback: _checkArgIsPositiveInteger,
-			help: "Specify the history lines in 'ansi' ${_defaultValue(Configuration.defaultTerminalHistoryLines)}"
+			help: "Specify the history lines in 'xterm' ${_defaultValue(Configuration.defaultTerminalHistoryLines)}"
 		)
 
 	    ..addSeparator('Misc options:') // ---
@@ -208,8 +208,8 @@ void argParser(List<String> args, Configuration c, InputQueue i) {
 						case 'simple':
 							c.setOption('terminalType', TerminalType.simple);
 							break;
-						case 'ansi':
-							c.setOption('terminalType', TerminalType.ansi);
+						case 'xterm':
+							c.setOption('terminalType', TerminalType.xterm);
 							break;
 					}
 				} catch(e) {

lib/src/cli/common/primitives.dart

@@ -4,8 +4,9 @@ part of forandar.cli.primitives;
 /// 
 void includeWordsCli(VirtualMachine vm, Dictionary d) {
 	includeWordsCliStandardCore(vm, d);
+	includeWordsCliStandardOptionalFacility(vm, d);
 	includeWordsCliStandardOptionalFile(vm, d);
-	includeWordsCliStandardOptionalProgrammingTools(vm, d);
+	includeWordsCliStandardOptionalTools(vm, d);
 	includeWordsCliNotStandardExtra(vm, d);
 }
 
@@ -21,6 +22,21 @@ void includeWordsCliStandardCore(VirtualMachine vm, Dictionary d) {
 		stdout.write("${vm.dataStack.pop} ");
 	});
 
+	/// Receive one character char.
+	///
+	/// [KEY][link] ( -- char )
+	/// [link]: https://forth-standard.org/standard/core/KEY
+	d.addWordOver("KEY", () {
+		vm.dataStack.push(stdin.readByteSync());
+
+		if (vm.input.keyBuffer >= 0) {
+			vm.dataStack.push(vm.input.keyBuffer);
+			vm.source.keyBuffer = -1;
+		} else {
+			vm.dataStack.push(stdin.readByteSync());
+		}
+	});
+
 	/// Display one space.
 	///
 	/// [SPACE][link] ( -- )
@@ -53,6 +69,10 @@ void includeWordsCliStandardCore(VirtualMachine vm, Dictionary d) {
 	});
 }
 
+/// [The optional Facility word set][http://forth-standard.org/standard/facility]
+void includeWordsCliStandardOptionalFacility(VirtualMachine vm, Dictionary d) {
+}
+
 /// [The optional File-Access word set][http://forth-standard.org/standard/file]
 void includeWordsCliStandardOptionalFile(VirtualMachine vm, Dictionary d) {
 
@@ -63,7 +83,8 @@ void includeWordsCliStandardOptionalFile(VirtualMachine vm, Dictionary d) {
 	//d.addWordOver("INCLUDED", () {}); // TODO
 }
 
-void includeWordsCliStandardOptionalProgrammingTools(VirtualMachine vm, Dictionary d) {
+/// [The optional Programming-Tools word set][http://forth-standard.org/standard/tools]
+void includeWordsCliStandardOptionalTools(VirtualMachine vm, Dictionary d) {
 
 	// ? BYE
 

lib/src/cli/input.dart

@@ -9,7 +9,6 @@ import 'package:forandar/src/core/input.dart';
 import 'package:forandar/src/core/globals.dart';
 
 // Cli
-import 'package:forandar/src/cli/ansi.dart';
 import 'package:forandar/src/cli/terminal.dart';
 
 // The input queue adapted for the CLI interface.
@@ -27,14 +26,14 @@ class InputQueue extends InputQueueBase {
 		// Be the most compatible by default.
 		if (globalConfig.getOption('terminalType') == TerminalType.auto) {
 
-			if (Platform.isWindows) {
-				return await readLineFromSimpleTerminal();
+			if (Platform.isLinux || Platform.isMacOS) {
+				return await readLineFromXTerm();
 			} else {
-				return await readLineFromAnsiTerminal();
+				return await readLineFromSimpleTerminal();
 			}
 
-		} else if (globalConfig.getOption('terminalType') == TerminalType.ansi) {
-			return await readLineFromAnsiTerminal();
+		} else if (globalConfig.getOption('terminalType') == TerminalType.xterm) {
+			return await readLineFromXTerm();
 		} else {
 			return await readLineFromSimpleTerminal();
 		}
@@ -45,8 +44,8 @@ class InputQueue extends InputQueueBase {
 		return await stdin.readLineSync();
 	}
 
-	// An ANSI full-featured terminal, with extra functionality.
-	Future<String> readLineFromAnsiTerminal() async {
+	// An XTerm compatible full-featured terminal, with extra functionality.
+	Future<String> readLineFromXTerm() async {
 		return await Terminal.readLineSync(); // works, but problem is UTF8
 	}
 }