public void Evaluate(Environment env, int index, object value) { if (env == null) { throw new ArgumentNullException(nameof(env), "null environment"); } IAstNode current = Parameter(index); FactorNode factor = current as FactorNode; if (factor == null || !factor.IsNoPrefixPrimary) { throw new LepException("bad parameter"); } PrimaryNode primary = factor.Operand as PrimaryNode; if (primary == null || !primary.IsName) { throw new LepException("bad parameter"); } NameNode name = primary.Operand as NameNode; if (name == null) { throw new LepException("bad parameter"); } if (name.IsAnonymous) { return; } env.Set(name.Token.Text, value, Environment.LocalVariable); }
private IAstNode FunctionDefinition() { Skip("#"); Token name = _lexer.Read(); if (!name.IsIdentifier || _reserved.Contains(name.Text)) throw new ParseException(name); IAstNode funcname = new NameNode(name); IAstNode parameters = new ParameterNode((TupleNode)Tuple()); IAstNode body = Block(); return new FunctionDefinitionNode(new Collection<IAstNode>() { funcname, parameters, body }); }
private object Assign(Environment env, PrimaryNode left, string op, object rvalue, int type) { if (env == null) { throw new ArgumentNullException(nameof(env), "null environment"); } if (left == null) { throw new ArgumentNullException(nameof(left), "null left name"); } if (op == null) { throw new ArgumentNullException(nameof(op), "null operator"); } if (left.IsName) { NameNode var = (NameNode)left.Operand; if (op == "=") { env.Set(var.Name, rvalue, type); return(rvalue); } else { object name = env.Get(var.Name, type); if (name == null) { throw new LepException("undefined name: " + var.Name, this); } else { object result = ComputeOperator(name, op.Substring(0, op.Length - 1), rvalue); env.Set(var.Name, result, type); return(result); } } } else { ArrayReferenceNode arrRef = left.Suffix(0) as ArrayReferenceNode; if (arrRef != null) { object lvalue = left.EvaluateSub(env, 1, type); object[] arr = lvalue as object[]; if (arr != null) { object index = arrRef.Index.Evaluate(env); if (index is int) { return(arr[(int)index] = rvalue); } } Dictionary <object, object> table = lvalue as Dictionary <object, object>; if (table != null) { object index = arrRef.Index.Evaluate(env); return(table[index] = rvalue); } } } throw new LepException("bad assignment", this); }