Exception throwing when required, and fixes for unit tests

Upsilon/Binder/Binder.cs

@@ -201,12 +201,6 @@ namespace Upsilon.Binder
             {
                 var variableExpression =(BoundVariableExpression) expression;
                 var function = (FunctionVariableSymbol)variableExpression.Variable.VariableSymbol;
-                if (function.Parameters.Length != parameters.Count)
-                {
-                    _diagnostics.LogError($"Invalid number of parameters for function '{function.Name}'. " +
-                                          $"Expected '{function.Parameters.Length}', got '{parameters.Count}'", e.Span);
-                    return new BoundLiteralExpression(new ScriptNull(), e.Span);
-                }
                 if (!function.IsBound)
                 {
                     Scope = new BoundScope(Scope);

Upsilon/Diagnostics.cs

@@ -1,5 +1,6 @@
 using System.Collections.Generic;
 using Upsilon.BaseTypes;
+using Upsilon.Exceptions;
 using Upsilon.Parser;
 using Upsilon.Text;
 
@@ -9,10 +10,12 @@ namespace Upsilon
     {
         public SourceText ScriptString { get; }
         public readonly List<DiagnosticsMessage> Messages = new List<DiagnosticsMessage>();
+        public bool ThrowsOnError { get; }
 
-        public Diagnostics(SourceText scriptString)
+        public Diagnostics(SourceText scriptString, bool throwsOnError)
         {
             ScriptString = scriptString;
+            ThrowsOnError = throwsOnError;
         }
 
         public void Log(DiagnosticLevel level, string message, TextSpan location)
@@ -22,6 +25,12 @@ namespace Upsilon
 
         public void LogError(string message, TextSpan location)
         {
+            if (ThrowsOnError)
+            {
+                var linePos = ScriptString.GetLinePosition(location.Start);
+                var line = ScriptString.GetLine(linePos.Line);
+                throw new ParseException(message, linePos.Line, linePos.Pos, line);
+            }
             Log(DiagnosticLevel.Error, message, location);
         }
 

Upsilon/Evaluator/Script.cs

@@ -27,7 +27,7 @@ namespace Upsilon.Evaluator
             Options = options;
             _scriptString = scriptString;
             ScriptString = new SourceText(scriptString);
-            Diagnostics = new Diagnostics(ScriptString);
+            Diagnostics = new Diagnostics(ScriptString, options.ThrowExceptionOnError);
 
             var staticBoundScope = options.OverrideStaticBoundScope ?? StaticScope.BoundScope;
             var boundScope = BoundScope.WithReadOnlyScope(staticBoundScope);
@@ -38,10 +38,10 @@ namespace Upsilon.Evaluator
             Evaluator = Evaluator.CreateWithSetScope(Diagnostics, Scope);
         }
 
-        private Script(string scriptString, Binder.Binder binder, Evaluator evaluator)
+        private Script(string scriptString, Binder.Binder binder, Evaluator evaluator, ScriptOptions options)
         {
             ScriptString = new SourceText(scriptString);
-            Diagnostics  = new Diagnostics(ScriptString);
+            Diagnostics  = new Diagnostics(ScriptString, Options.ThrowExceptionOnError);
             Binder       = new Binder.Binder(Diagnostics, binder.Scope.Variables);
             Evaluator    = new Evaluator( Diagnostics, evaluator.Scope.Variables);
             Scope        = Evaluator.Scope;
@@ -50,7 +50,7 @@ namespace Upsilon.Evaluator
 
         internal static Script ContinueWith(Script previousScript, string scriptString)
         {
-            var s = new Script(scriptString, previousScript.Binder, previousScript.Evaluator);
+            var s = new Script(scriptString, previousScript.Binder, previousScript.Evaluator, previousScript.Options);
             return s;
         }
 

Upsilon/Exceptions/ParseException.cs

@@ -0,0 +1,28 @@
+using System;
+using Upsilon.Text;
+
+namespace Upsilon.Exceptions
+{
+    public class ParseException : Exception
+    {
+        public string ErrorMessage { get; }
+        public int Line { get; }
+        public int Character { get; }
+        public string ErrorLine { get; }
+
+        public ParseException(string errorMessage, int line, int character, string errorLine)
+        {
+            ErrorMessage = errorMessage;
+            Line = line;
+            Character = character;
+            ErrorLine = errorLine;
+        }
+
+        public override string ToString()
+        {
+            return $"{ErrorMessage} at ({Line}, {Character})\n{ErrorLine}";
+        }
+
+        public override string Message => ToString();
+    }
+}

Upsilon/Executor.cs

@@ -44,13 +44,13 @@ namespace Upsilon
 
         public static T EvaluateFunction<T>(string input, string function, object[] parameters = null, ScriptOptions options = null)
         {
-            var script = ParseInput(input, options);
+            var script = ParseInputAndEvaluate(input, options);
             return script.EvaluateFunction<T>(function, parameters);
         }
 
         public static object EvaluateFunction(string input, string function, object[] parameters = null, ScriptOptions options = null)
         {
-            var script = ParseInput(input, options);
+            var script = ParseInputAndEvaluate(input, options);
             return script.EvaluateFunction(function, parameters);
         }
     }

Upsilon/Parser/StatementSyntax/IfStatementSyntax.cs

@@ -16,7 +16,9 @@ namespace Upsilon.Parser
             ThenToken = thenToken;
             Block = block;
             EndToken = endToken;
-            Span = new TextSpan(IfToken.Span.Start, EndToken.Span.End - IfToken.Span.Start);
+            var end = Block.Span.End;
+            if (EndToken != null) end = EndToken.Span.End;
+            Span = new TextSpan(IfToken.Span.Start, end - IfToken.Span.Start);
         }
 
         public IfStatementSyntax(SyntaxToken ifToken, ExpressionStatementSyntax condition, SyntaxToken thenToken,
@@ -27,7 +29,7 @@ namespace Upsilon.Parser
             ThenToken     = thenToken;
             Block         = block;
             ElseStatement = elseStatement;
-            Span = new TextSpan(IfToken.Span.Start, EndToken.Span.End - IfToken.Span.Start);
+            Span = new TextSpan(IfToken.Span.Start, ElseStatement.Span.End - IfToken.Span.Start);
         }
 
         public IfStatementSyntax(SyntaxToken ifToken, ExpressionStatementSyntax condition, SyntaxToken thenToken,

Upsilon/Text/SourceText.cs

@@ -85,6 +85,12 @@ namespace Upsilon.Text
             return _text.Length;
         }
 
+        public string GetLine(int linePosition)
+        {
+            var line = _lines[linePosition];
+            return GetSpan(line.Start, line.LineLength);
+        }
+
         public SourceTextLine GetLineInfo(int lineIndex)
         {
             return _lines[lineIndex];

UpsilonTests/GeneralTests/FunctionTests.cs

@@ -1,5 +1,6 @@
 using Upsilon;
 using Upsilon.Evaluator;
+using Upsilon.Exceptions;
 using Xunit;
 
 namespace UpsilonTests.GeneralTests
@@ -50,8 +51,7 @@ function testFunc (var1)
 end
 testFunc(100)
 ";
-            var script = Executor.ParseInputAndEvaluate(input, Options);
+            Assert.Throws<ParseException>(() => Executor.ParseInputAndEvaluate(input, Options));
-            Assert.True(script.HasVariable("testFunc"));
         }
 
         [Fact]

UpsilonTests/GeneralTests/TableTests.cs

@@ -1,5 +1,6 @@
 using Upsilon;
 using Upsilon.Evaluator;
+using Upsilon.Exceptions;
 using Xunit;
 
 namespace UpsilonTests.GeneralTests
@@ -49,7 +50,7 @@ table = {
 }
 return table[""test""]
 ";
-            Executor.EvaluateScript<long>(input, Options);
+            Assert.Throws<ParseException>(() => Executor.EvaluateScript<long>(input, Options));
         }
 
         [Fact]

UpsilonTests/GeneralTests/UserDataDictionaryTests.cs

@@ -21,7 +21,7 @@ function getValue(arr)
     return arr[""here""]
 end
 ";
-            var evaluated = Executor.EvaluateScript<long>(input, Options);
+            var evaluated = Executor.EvaluateFunction<long>(input, "getValue", new[] {arr}, Options);
             Assert.Equal(1683, evaluated);
         }
 

UpsilonTests/GeneralTests/UserDataListTests.cs

@@ -16,7 +16,7 @@ function getValue(arr)
     return arr[3]
 end
 ";
-            var evaluated = Executor.EvaluateScript<long>(input, Options);
+            var evaluated = Executor.EvaluateFunction<long>(input, "getValue", new []{arr}, Options);
             Assert.Equal(56, evaluated);
         }
 
@@ -29,7 +29,7 @@ function getValue(arr)
     return arr[2]
 end
 ";
-            var evaluated = Executor.EvaluateScript<long>(input, Options);
+            var evaluated = Executor.EvaluateFunction<long>(input, "getValue", new []{arr}, Options);
             Assert.Equal(30, evaluated);
         }
 

UpsilonTests/GeneralTests/UserDataTests.cs

@@ -2,6 +2,7 @@ using System;
 using Upsilon;
 using Upsilon.BaseTypes.UserData;
 using Upsilon.Evaluator;
+using Upsilon.Exceptions;
 using Xunit;
 
 // ReSharper disable UnusedMember.Local
@@ -68,7 +69,7 @@ function test(o)
     o.FieldStringSet = ""Test""
 end
 ";
-            var result = Executor.EvaluateFunction<string>(input, "test", new[] {obj}, Options);
+            Executor.EvaluateFunction(input, "test", new[] {obj}, Options);
             Assert.Equal("Test", obj.FieldStringSet);
         }
 
@@ -81,7 +82,7 @@ function test(o)
     o.testMethod()
 end
 ";
-            Executor.EvaluateFunction<string>(input, "test", new[] {obj}, Options);
+            Executor.EvaluateFunction(input, "test", new[] {obj}, Options);
         }
 
         [Fact]
@@ -106,7 +107,7 @@ function test(o)
     return o._privateTestField
 end
 ";
-            Executor.EvaluateFunction<string>(input, "test", new[] {obj}, Options);
+            Assert.Throws<ParseException>(() => Executor.EvaluateFunction<string>(input, "test", new[] {obj}, Options));
         }
 
         [Fact]
@@ -118,7 +119,7 @@ function test(o)
     o.GetOnly = true
 end
 ";
-            Executor.EvaluateFunction<string>(input, "test", new[] {obj}, Options);
+            Assert.Throws<ParseException>(() => Executor.EvaluateFunction(input, "test", new[] {obj}, Options));
             Assert.False(obj.GetOnly);
         }
 
@@ -131,7 +132,7 @@ function test(o)
     o.PrivateSet = true
 end
 ";
-            Executor.EvaluateFunction<string>(input, "test", new[] {obj}, Options);
+            Assert.Throws<ParseException>(() => Executor.EvaluateFunction<string>(input, "test", new[] {obj}, Options));
             Assert.False(obj.PrivateSet);
         }
 

UpsilonTests/StandardLibraryTests/BasicFunctionsTests.cs

@@ -15,7 +15,7 @@ namespace UpsilonTests.StandardLibraryTests
         public void AssertTest()
         {
             Executor.EvaluateScript("assert(true)", Options);
-            Assert.Throws<Exception>(() => Executor.EvaluateScript("assert(true)", Options));
+            Assert.Throws<Exception>(() => Executor.EvaluateScript("assert(false)", Options));
         }
 
         [Fact]

Ycicle/Program.cs

@@ -13,7 +13,10 @@ namespace Ycicle
         {
             Console.WriteLine("Upsilon REPL");
             Script script = null;
-            var (evaluationScope, boundScope) = StaticScope.CreateStandardLibrary();
+            var options = new ScriptOptions()
+            {
+                ThrowExceptionOnError = false
+            };
 
             while (true)
             {
@@ -21,7 +24,7 @@ namespace Ycicle
                 var input = Console.ReadLine();
                 if (input == "exit") return;
                 script = script == null
-                    ? Executor.ParseInput(input)
+                    ? Executor.ParseInput(input, options)
                     : Executor.ContinueWith(script, input);
 
                 if (script.Diagnostics.Messages.Count > 0)