/// <summary> /// Parses a function definition. /// </summary> /// <remarks> /// Assumes the 'function' keyword has already been consumed. /// </remarks> internal static ExpressionBase Parse(PositionalTokenizer tokenizer, int line = 0, int column = 0) { var locationStart = new TextLocation(line, column); // location of 'function' keyword ExpressionBase.SkipWhitespace(tokenizer); line = tokenizer.Line; column = tokenizer.Column; var functionName = tokenizer.ReadIdentifier(); var functionNameVariable = new VariableDefinitionExpression(functionName.ToString(), line, column); var function = new UserFunctionDefinitionExpression(functionNameVariable); function.Location = new TextRange(locationStart.Line, locationStart.Column, 0, 0); if (functionName.IsEmpty) { return(ExpressionBase.ParseError(tokenizer, "Invalid function name")); } return(function.Parse(tokenizer)); }
private static ExpressionBase ParseClauseCore(PositionalTokenizer tokenizer) { ExpressionBase clause; switch (tokenizer.NextChar) { case '!': tokenizer.Advance(); clause = ParseClause(tokenizer); if (clause.Type == ExpressionType.ParseError) { return(clause); } return(new ConditionalExpression(null, ConditionalOperation.Not, clause)); case '(': if (AnonymousUserFunctionDefinitionExpression.IsAnonymousParameterList(tokenizer)) { return(AnonymousUserFunctionDefinitionExpression.ParseAnonymous(tokenizer)); } tokenizer.Advance(); clause = ExpressionBase.Parse(tokenizer); if (clause.Type == ExpressionType.ParseError) { return(clause); } if (tokenizer.NextChar != ')') { if (tokenizer.NextChar == '\0') { return(ParseError(tokenizer, "No closing parenthesis found")); } return(ParseError(tokenizer, "Expected closing parenthesis, found: " + tokenizer.NextChar)); } clause.IsLogicalUnit = true; tokenizer.Advance(); return(clause); case '"': try { var stringValue = tokenizer.ReadQuotedString().ToString(); return(new StringConstantExpression(stringValue)); } catch (InvalidOperationException ex) { return(ParseError(tokenizer, ex.Message)); } case '0': case '1': case '2': case '3': case '4': case '5': case '6': case '7': case '8': case '9': return(ParseNumber(tokenizer, true)); case '-': var tokenStart = tokenizer.Location; tokenizer.Advance(); if (tokenizer.NextChar >= '0' && tokenizer.NextChar <= '9') { var result = ParseNumber(tokenizer, false); var tokenEnd = result.Location.End; switch (result.Type) { case ExpressionType.IntegerConstant: result = new IntegerConstantExpression(-((IntegerConstantExpression)result).Value); break; case ExpressionType.FloatConstant: result = new FloatConstantExpression(-((FloatConstantExpression)result).Value); break; default: return(result); } result.Location = new TextRange(tokenStart, tokenEnd); return(result); } return(ParseError(tokenizer, "Minus without value", tokenStart.Line, tokenStart.Column)); case '{': tokenizer.Advance(); return(DictionaryExpression.Parse(tokenizer)); case '[': tokenizer.Advance(); return(ParseArray(tokenizer)); default: var line = tokenizer.Line; var column = tokenizer.Column; var identifier = tokenizer.ReadIdentifier(); if (identifier.IsEmpty) { var error = ParseError(tokenizer, "Unexpected character: " + tokenizer.NextChar); tokenizer.Advance(); return(error); } SkipWhitespace(tokenizer); if (identifier == "return") { clause = ExpressionBase.Parse(tokenizer); if (clause.Type == ExpressionType.ParseError) { return(clause); } return(new ReturnExpression(new KeywordExpression(identifier.ToString(), line, column), clause)); } if (identifier == "function") { return(UserFunctionDefinitionExpression.Parse(tokenizer, line, column)); } if (identifier == "for") { return(ForExpression.Parse(tokenizer, line, column)); } if (identifier == "if") { return(IfExpression.Parse(tokenizer, line, column)); } if (identifier == "true") { return(new BooleanConstantExpression(true, line, column)); } if (identifier == "false") { return(new BooleanConstantExpression(false, line, column)); } if (tokenizer.NextChar == '(') { tokenizer.Advance(); var parameters = new List <ExpressionBase>(); ParseParameters(tokenizer, parameters); var functionCall = new FunctionCallExpression(new FunctionNameExpression(identifier.ToString(), line, column), parameters); functionCall.Location = new TextRange(line, column, tokenizer.Line, tokenizer.Column - 1); return(functionCall); } if (tokenizer.NextChar == '[') { IndexedVariableExpression parent = null; do { tokenizer.Advance(); var index = ExpressionBase.Parse(tokenizer); if (index.Type == ExpressionType.ParseError) { return(index); } SkipWhitespace(tokenizer); if (tokenizer.NextChar != ']') { return(ParseError(tokenizer, "Expecting closing bracket after index")); } tokenizer.Advance(); SkipWhitespace(tokenizer); if (parent != null) { parent = new IndexedVariableExpression(parent, index); } else { parent = new IndexedVariableExpression(new VariableExpression(identifier.ToString(), line, column), index); } } while (tokenizer.NextChar == '['); return(parent); } return(new VariableExpression(identifier.ToString(), line, column)); } }