/// <summary> /// Main loop. /// Good default for all the flags is `false` /// </summary> /// <param name="resetVars">If true, all scopes are DELETED before running</param> /// <param name="traceExecution">If true, console output of state is written</param> /// <param name="singleStep">If true, the interpreter will run a single step, then return. Internal `eval` statements will run to completion</param> public ExecutionResult Execute(bool resetVars, bool traceExecution, bool singleStep) { double evalResult; _runningVerbose = traceExecution; if (resetVars) { _memory.Variables.Clear(); } while (_position < program.Count) { _stepsTaken++; //if (stepsTaken > 1000) throw new Exception("trap"); // Prevent stackoverflow. // Ex: if(true 1 10 20) if ((_stepsTaken & 127) == 0 && _valueStack.Count > 100) { var oldValues = _valueStack.ToArray(); _valueStack = new Stack <double>(oldValues.Skip(oldValues.Length - 100)); } double word = program[_position]; if (traceExecution) { _output.WriteLine(" stack :" + string.Join(", ", _valueStack.ToArray().Select(t => _memory.DiagnosticString(t, DebugSymbols)))); _output.WriteLine(" #" + _stepsTaken + "; p=" + _position + "; w=" + _memory.DiagnosticString(word, DebugSymbols)); } var type = NanTags.TypeOf(word); switch (type) { case DataType.Invalid: throw new Exception("Unknown code point at " + _position); case DataType.Opcode: // decode opcode and do stuff NanTags.DecodeOpCode(word, out var codeClass, out var codeAction, out var p1, out var p2); ProcessOpCode(codeClass, codeAction, p1, p2, ref _position, _valueStack, _returnStack, word); break; default: _valueStack.Push(word); // these could be raw doubles, encoded real values, or references/pointers break; } _position++; if (singleStep) { return new ExecutionResult { State = ExecutionState.Paused, Result = NanTags.EncodeNonValue(NonValueType.Not_a_Result) } } ; } if (_valueStack.Count != 0) { evalResult = _valueStack.Pop(); } else { evalResult = NanTags.EncodeNonValue(NonValueType.Void); } _valueStack.Clear(); return(new ExecutionResult { State = ExecutionState.Complete, Result = evalResult }); }
private double EvaluateBuiltInFunction(ref int position, FuncDef kind, int nbParams, double[] param, Stack <int> returnStack, Stack <double> valueStack) { switch (kind) { // each element equal to the first case FuncDef.Equal: if (nbParams < 2) { throw new Exception("equals ( = ) must have at least two things to compare"); } return(NanTags.EncodeBool(ListEquals(param))); // Each element smaller than the last case FuncDef.GreaterThan: if (nbParams < 2) { throw new Exception("greater than ( > ) must have at least two things to compare"); } return(NanTags.EncodeBool(FoldGreaterThan(param))); // Each element larger than the last case FuncDef.LessThan: if (nbParams < 2) { throw new Exception("less than ( < ) must have at least two things to compare"); } return(NanTags.EncodeBool(FoldLessThan(param))); // Each element DIFFERENT TO THE FIRST (does not check set uniqueness!) case FuncDef.NotEqual: if (nbParams < 2) { throw new Exception("not-equal ( <> ) must have at least two things to compare"); } return(NanTags.EncodeBool(!ListEquals(param))); case FuncDef.Assert: if (nbParams < 1) { return(NanTags.VoidReturn()); // assert nothing passes } var condition = param.ElementAt(0); if (_memory.CastBoolean(condition) == false) { var msg = ConcatList(param, 1); throw new Exception("Assertion failed: " + msg); } return(NanTags.VoidReturn()); case FuncDef.Random: if (nbParams < 1) { return(rnd.NextDouble()); // 0 params - any size } if (nbParams < 2) { return(rnd.Next(_memory.CastInt(param.ElementAt(0)))); // 1 param - max size } return(rnd.Next(_memory.CastInt(param.ElementAt(0)), _memory.CastInt(param.ElementAt(1)))); // 2 params - range case FuncDef.Eval: var reader = new SourceCodeTokeniser(); var statements = _memory.CastString(param.ElementAt(0)); var programTmp = reader.Read(statements, false); var bin = ToNanCodeCompiler.CompileRoot(programTmp, false); var interpreter = new ByteCodeInterpreter(); interpreter.Init(new RuntimeMemoryModel(bin, _memory.Variables), _input, _output, DebugSymbols); return(interpreter.Execute(false, _runningVerbose, false).Result); case FuncDef.Call: NanTags.DecodePointer(param.ElementAt(0), out var target, out var type); if (type != DataType.PtrString && type != DataType.PtrStaticString) { throw new Exception("Tried to call a function by name, but passed a '" + type + "' at " + position); } // this should be a string, but we need a function name hash -- so calculate it: var strName = _memory.DereferenceString(target); var functionNameHash = NanTags.GetCrushedName(strName); nbParams--; var newParam = param.Skip(1).ToArray(); return(EvaluateFunctionCall(ref position, functionNameHash, nbParams, newParam, returnStack, valueStack)); case FuncDef.LogicNot: if (nbParams != 1) { throw new Exception("'not' should be called with one argument"); } var bval = _memory.CastBoolean(param.ElementAt(0)); return(NanTags.EncodeBool(!bval)); case FuncDef.LogicOr: { bool more = nbParams > 0; int i = 0; while (more) { var bresult = _memory.CastBoolean(param.ElementAt(i)); if (bresult) { return(NanTags.EncodeBool(true)); } i++; more = i < nbParams; } return(NanTags.EncodeBool(false)); } case FuncDef.LogicAnd: { bool more = nbParams > 0; int i = 0; while (more) { var bresult = _memory.CastBoolean(param.ElementAt(i)); if (!bresult) { return(NanTags.EncodeBool(false)); } i++; more = i < nbParams; } return(NanTags.EncodeBool(true)); } case FuncDef.ReadKey: return(_memory.StoreStringAndGetReference(((char)_input.Read()).ToString())); case FuncDef.ReadLine: return(_memory.StoreStringAndGetReference(_input.ReadLine())); case FuncDef.Print: { string lastStr = null; foreach (var v in param) { lastStr = _memory.CastString(v); _output.Write(lastStr); } if (lastStr != "") { _output.WriteLine(); } } return(NanTags.VoidReturn()); case FuncDef.Substring: if (nbParams == 2) { var newString = _memory.CastString(param.ElementAt(0)).Substring(_memory.CastInt(param.ElementAt(1))); return(_memory.StoreStringAndGetReference(newString)); } else if (nbParams == 3) { int start = _memory.CastInt(param.ElementAt(1)); int length = _memory.CastInt(param.ElementAt(2)); string s = _memory.CastString(param.ElementAt(0)).Substring(start, length); return(_memory.StoreStringAndGetReference(s)); } else { throw new Exception("'Substring' should be called with 2 or 3 parameters"); } case FuncDef.Length: return(_memory.CastString(param.ElementAt(0)).Length); case FuncDef.Replace: if (nbParams != 3) { throw new Exception("'Replace' should be called with 3 parameters"); } string exp = _memory.CastString(param.ElementAt(0)); string oldValue = _memory.CastString(param.ElementAt(1)); string newValue = _memory.CastString(param.ElementAt(2)); exp = exp.Replace(oldValue, newValue); return(_memory.StoreStringAndGetReference(exp)); case FuncDef.Concat: var builder = new StringBuilder(); foreach (var v in param) { builder.Append(_memory.CastString(v)); } return(_memory.StoreStringAndGetReference(builder.ToString())); case FuncDef.UnitEmpty: { // valueless marker (like an empty object) return(NanTags.EncodeNonValue(NonValueType.Unit)); } case FuncDef.MathAdd: if (nbParams == 1) { return(param[0]); } return(param.ChainSum()); case FuncDef.MathSub: if (nbParams == 1) { return(-param[0]); } return(param.ChainDifference()); case FuncDef.MathProd: if (nbParams == 1) { throw new Exception("Uniary '*' is not supported"); } return(param.ChainProduct()); case FuncDef.MathDiv: if (nbParams == 1) { throw new Exception("Uniary '/' is not supported"); } return(param.ChainDivide()); case FuncDef.MathMod: if (nbParams == 1) { return(param[0] % 2); } return(param.ChainRemainder()); default: throw new Exception("Unrecognised built-in! Type = " + ((int)kind)); } }