SLEEP statement, LIST bug fix, and PLOT sample.

treytomes · Dec 31, 2021 · 0a0db31 · 0a0db31
1 parent 7443109
commit 0a0db31
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Showing 15 changed files with 251 additions and 82 deletions.
diff --git a/src/ECMABasic.Core/ComplexTokenReader.cs b/src/ECMABasic.Core/ComplexTokenReader.cs
@@ -16,10 +16,6 @@ namespace ECMABasic.Core
 	/// </remarks>
 	public class ComplexTokenReader
 	{
-		/// <summary>
-		/// The index into _tokens.
-		/// </summary>
-		private int _tokenIndex;
 		private readonly List<Token> _tokens;
 
 		private ComplexTokenReader(SimpleTokenReader reader)
@@ -33,7 +29,12 @@ private ComplexTokenReader(SimpleTokenReader reader)
 			reader.Dispose();
 		}
 
-		public bool IsAtEnd => _tokenIndex >= _tokens.Count;
+		/// <summary>
+		/// The index into _tokens.
+		/// </summary>
+		public int TokenIndex { get; private set; }
+
+		public bool IsAtEnd => TokenIndex >= _tokens.Count;
 
 		public static ComplexTokenReader FromFile(string filename)
 		{
@@ -158,7 +159,7 @@ public static ComplexTokenReader FromText(string text)
 		/// <exception cref="UnexpectedTokenException">Throws an exception if the token type doesn't match what was expected.</exception>
 		public Token Next(TokenType type, bool throwOnError = true, string pattern = null)
 		{
-			var startPosition = _tokenIndex;
+			var startPosition = TokenIndex;
 			var token = Next();
 			if ((token == null) || (token.Type != type) || ((pattern != null) && !Regex.IsMatch(token.Text, @"^" + pattern + @"$", RegexOptions.Singleline)))
 			{
@@ -168,7 +169,7 @@ public Token Next(TokenType type, bool throwOnError = true, string pattern = nul
 				}
 				else
 				{
-					_tokenIndex = startPosition;
+					TokenIndex = startPosition;
 					return null;
 				}
 			}
@@ -274,7 +275,7 @@ public Token Next()
 
 		private Token ReadRestOfString(Token start)
 		{
-			var startIndex = _tokenIndex;
+			var startIndex = TokenIndex;
 			List<Token> stringTokens = new() { start };
 
 			while (true)
@@ -283,7 +284,7 @@ private Token ReadRestOfString(Token start)
 				if ((token == null) || (token.Type == TokenType.EndOfLine))
 				{
 					// Rewind.
-					_tokenIndex = startIndex;
+					TokenIndex = startIndex;
 					return null;
 				}
 
@@ -307,8 +308,8 @@ private Token Read()
 				return null;
 			}
 
-			var token = _tokens[_tokenIndex];
-			_tokenIndex++;
+			var token = _tokens[TokenIndex];
+			TokenIndex++;
 			return token;
 		}
 
@@ -318,16 +319,21 @@ public Token Peek()
 			{
 				return null;
 			}
-			return _tokens[_tokenIndex];
+			return _tokens[TokenIndex];
+		}
+
+		public void Seek(int index)
+		{
+			TokenIndex = index;
 		}
 
 		public void Rewind()
 		{
-			if (_tokenIndex == 0)
+			if (TokenIndex == 0)
 			{
 				return;
 			}
-			_tokenIndex--;
+			TokenIndex--;
 		}
 	}
 }
diff --git a/src/ECMABasic.Core/EnvironmentBase.cs b/src/ECMABasic.Core/EnvironmentBase.cs
@@ -13,12 +13,15 @@ public abstract class EnvironmentBase : IEnvironment
 
 		private readonly IBasicConfiguration _config;
 
-		public EnvironmentBase(IBasicConfiguration config = null)
+		public EnvironmentBase(Interpreter interpreter = null, IBasicConfiguration config = null)
 		{
+			Interpreter = interpreter ?? new Interpreter();
 			_config = config ?? MinimalBasicConfiguration.Instance;
 			Program = new Program();
 		}
 
+		public Interpreter Interpreter { get; }
+
 		/// <summary>
 		/// The line number currently being executed.
 		/// </summary>
@@ -114,5 +117,11 @@ public ICallStackContext PopCallStack()
 		}
 
 		public abstract void CheckForStopRequest();
+
+		public bool LoadFile(string filename)
+		{
+			Program.Clear();
+			return Interpreter.InterpretProgramFromFile(this, filename);
+		}
 	}
 }
diff --git a/src/ECMABasic.Core/IEnvironment.cs b/src/ECMABasic.Core/IEnvironment.cs
@@ -5,6 +5,11 @@
 	/// </summary>
 	public interface IEnvironment : IErrorReporter
 	{
+		/// <summary>
+		/// The active interpreter.
+		/// </summary>
+		public Interpreter Interpreter { get; }
+
 		/// <summary>
 		/// The full program, ready to execute.
 		/// </summary>
@@ -95,5 +100,11 @@ public interface IEnvironment : IErrorReporter
 		/// Used by the Program evaluator to see if a stop has been requested.
 		/// </summary>
 		public void CheckForStopRequest();
+
+		/// <summary>
+		/// Load and interpret a file.
+		/// </summary>
+		/// <param name="filename">The file to load.</param>
+		public bool LoadFile(string filename);
 	}
 }
diff --git a/src/ECMABasic.Core/Interpreter.cs b/src/ECMABasic.Core/Interpreter.cs
@@ -17,11 +17,9 @@ public class Interpreter
 
 		protected ComplexTokenReader _reader;
 		private readonly IBasicConfiguration _config;
-		protected readonly IEnvironment _env;
 
-		public Interpreter(IEnvironment env, IBasicConfiguration config = null)
+		public Interpreter(IBasicConfiguration config = null)
 		{
-			_env = env;
 			_config = config ?? MinimalBasicConfiguration.Instance;
 
 			_lineStatements = new List<StatementParser>()
@@ -49,8 +47,8 @@ public Interpreter(IEnvironment env, IBasicConfiguration config = null)
 		/// <returns>Was the input interpreted successfully?</returns>
 		public static bool FromText(string text, IEnvironment env, IBasicConfiguration config = null)
 		{
-			var interpreter = new Interpreter(env, config);
-			return interpreter.InterpretProgramFromText(text);
+			var interpreter = new Interpreter(config);
+			return interpreter.InterpretProgramFromText(env, text);
 		}
 
 		/// <summary>
@@ -61,8 +59,17 @@ public static bool FromText(string text, IEnvironment env, IBasicConfiguration c
 		/// <returns>Was the input interpreted successfully?</returns>
 		public static bool FromFile(string path, IEnvironment env, IBasicConfiguration config = null)
 		{
-			var interpreter = new Interpreter(env, config);
-			return interpreter.InterpretProgramFromFile(path);
+			var interpreter = new Interpreter(config);
+			return interpreter.InterpretProgramFromFile(env, path);
+		}
+
+		/// <summary>
+		/// Allow interpretation of additional statements.
+		/// </summary>
+		/// <param name="additionalStatements">The statements to add to the interpreter.</param>
+		public void InjectStatements(IEnumerable<StatementParser> additionalStatements)
+		{
+			_lineStatements.AddRange(additionalStatements);
 		}
 
 		/// <summary>
@@ -71,10 +78,10 @@ public static bool FromFile(string path, IEnvironment env, IBasicConfiguration c
 		/// <param name="path">The path to the file to interpret.</param>
 		/// <param name="reporter">A receiver for error messages.</param>
 		/// <returns>Was the input interpreted successfully?</returns>
-		public bool InterpretProgramFromFile(string path)
+		public bool InterpretProgramFromFile(IEnvironment env, string path)
 		{
 			_reader = ComplexTokenReader.FromFile(path);
-			return InterpretProgram();
+			return InterpretProgram(env);
 		}
 
 		/// <summary>
@@ -83,13 +90,13 @@ public bool InterpretProgramFromFile(string path)
 		/// <param name="text">The text to interpret.</param>
 		/// <param name="reporter">A receiver for error messages.</param>
 		/// <returns>Was the input interpreted successfully?</returns>
-		public bool InterpretProgramFromText(string text)
+		public bool InterpretProgramFromText(IEnvironment env, string text)
 		{
 			_reader = ComplexTokenReader.FromText(text);
-			return InterpretProgram();
+			return InterpretProgram(env);
 		}
 
-		private bool InterpretProgram()
+		private bool InterpretProgram(IEnvironment env)
 		{
 			try
 			{
@@ -102,7 +109,7 @@ private bool InterpretProgram()
 					}
 					else
 					{
-						_env.Program.Insert(line);
+						env.Program.Insert(line);
 					}
 				}
 
@@ -115,7 +122,7 @@ private bool InterpretProgram()
 			}
 			catch (SyntaxException e)
 			{
-				_env.ReportError(e.Message);
+				env.ReportError(e.Message);
 				return false;
 			}
 		}

diff --git a/src/ECMABasic.Core/NumericExpressionParser.cs b/src/ECMABasic.Core/NumericExpressionParser.cs
@@ -130,6 +130,7 @@ private IExpression ParseSums()
 			{
 				var space = _reader.Next(TokenType.Space, false);
 
+				var preSymbolIndex = _reader.TokenIndex;
 				var symbol = _reader.Next(TokenType.Symbol, false, @"\+|\-");
 				if (symbol == null)
 				{
@@ -143,6 +144,11 @@ private IExpression ParseSums()
 				_reader.Next(TokenType.Space, false);
 
 				var right = ParseProducts();
+				if (right == null)
+				{
+					_reader.Seek(preSymbolIndex);
+					return expr;
+				}
 
 				expr = symbol.Text switch
 				{
@@ -165,6 +171,7 @@ private IExpression ParseProducts()
 			{
 				var space = _reader.Next(TokenType.Space, false);
 
+				var preSymbolIndex = _reader.TokenIndex;
 				var symbol = _reader.Next(TokenType.Symbol, false, @"\*|\/");
 				if (symbol == null)
 				{
@@ -178,6 +185,11 @@ private IExpression ParseProducts()
 				_reader.Next(TokenType.Space, false);
 
 				var right = ParseUnary();
+				if (right == null)
+				{
+					_reader.Seek(preSymbolIndex);
+					return expr;
+				}
 
 				expr = symbol.Text switch
 				{
@@ -220,6 +232,7 @@ private IExpression ParseInvolution()
 			{
 				var space = _reader.Next(TokenType.Space, false);
 
+				var preSymbolIndex = _reader.TokenIndex;
 				var symbol = _reader.Next(TokenType.Symbol, false, @"\^");
 				if (symbol == null)
 				{
@@ -233,6 +246,11 @@ private IExpression ParseInvolution()
 				_reader.Next(TokenType.Space, false);
 
 				var right = ParseAtomic(true);
+				if (right == null)
+				{
+					_reader.Seek(preSymbolIndex);
+					return expr;
+				}
 
 				expr = new InvolutionExpression(expr, right);
 			}

diff --git a/src/ECMABasic.Core/Parsers/PrintStatementParser.cs b/src/ECMABasic.Core/Parsers/PrintStatementParser.cs
@@ -76,18 +76,13 @@ private static IPrintItemSeparator ProcessPrintSeparator(ComplexTokenReader read
 
 		private static IPrintItem ProcessPrintItem(ComplexTokenReader reader, int? lineNumber = null)
 		{
-			//if (lineNumber == 680)
-			//{
-			//	var a = 0;
-			//}
-
-			IPrintItem expr = ParseExpression(reader, lineNumber, false);
+			var expr = ProcessTabExpression(reader, lineNumber);
 			if (expr != null)
 			{
 				return expr;
 			}
 
-			expr = ProcessTabExpression(reader, lineNumber);
+			expr = ParseExpression(reader, lineNumber, false);
 			if (expr != null)
 			{
 				return expr;

diff --git a/src/ECMABasic55/ConsoleEnvironment.cs b/src/ECMABasic55/ConsoleEnvironment.cs
@@ -1,12 +1,17 @@
 using ECMABasic.Core;
+using ECMABasic.Core.Configuration;
 using ECMABasic.Core.Exceptions;
-using ECMABasic.Core.Statements;
 using System;
 
 namespace ECMABasic55
 {
-	class ConsoleEnvironment : EnvironmentBase
+	public class ConsoleEnvironment : EnvironmentBase
 	{
+		public ConsoleEnvironment(Interpreter interpreter = null, IBasicConfiguration config = null)
+			: base(interpreter, config)
+		{
+		}
+
 		public override int TerminalRow
 		{
 			get

diff --git a/src/ECMABasic55/PLOT.BAS b/src/ECMABasic55/PLOT.BAS
@@ -0,0 +1,8 @@
+10 LET P=3.14159265359
+20 LET A=0
+30 LET R=((COS(A*(P/180))+1)*16)+8
+50 SLEEP 100
+40 PRINT TAB(R);"*"
+80 LET A=A+16
+90 GOTO 30
+100 END