public SyntaxTreeVisitor(ParserConfiguration <IN, OUT> conf, object parserInstance)
{
ParserClass = ParserClass;
Configuration = conf;
ParserVsisitorInstance = parserInstance;
}
public static BuildResult <ParserConfiguration <IN, OUT> > BuildExpressionRules <IN, OUT>(
ParserConfiguration <IN, OUT> configuration, Type parserClass,
BuildResult <ParserConfiguration <IN, OUT> > result) where IN : struct
{
var methods = parserClass.GetMethods().ToList();
methods = methods.Where(m =>
{
var attributes = m.GetCustomAttributes().ToList();
var attr = attributes.Find(a => a.GetType() == typeof(OperationAttribute));
return(attr != null);
}).ToList();
var operationsByPrecedence = new Dictionary <int, List <OperationMetaData <IN> > >();
methods.ForEach(m =>
{
var attributes =
(OperationAttribute[])m.GetCustomAttributes(typeof(OperationAttribute), true);
foreach (var attr in attributes)
{
var operation = new OperationMetaData <IN>(attr.Precedence, attr.Assoc, m, attr.Affix,
ConvertIntToEnum <IN>(attr.Token));
var operations = new List <OperationMetaData <IN> >();
if (operationsByPrecedence.ContainsKey(operation.Precedence))
{
operations = operationsByPrecedence[operation.Precedence];
}
operations.Add(operation);
operationsByPrecedence[operation.Precedence] = operations;
}
});
if (operationsByPrecedence.Count > 0)
{
methods = parserClass.GetMethods().ToList();
var operandMethod = methods.Find(m =>
{
var attributes = m.GetCustomAttributes().ToList();
var attr = attributes.Find(a => a.GetType() == typeof(OperandAttribute));
return(attr != null);
});
string operandNonTerminal = null;
if (operandMethod == null)
{
result.AddError(new ParserInitializationError(ErrorLevel.FATAL, "missing [operand] attribute"));
throw new Exception("missing [operand] attribute");
}
var production =
operandMethod.GetCustomAttributes().ToList()
.Find(attr => attr.GetType() == typeof(ProductionAttribute)) as ProductionAttribute;
if (production != null)
{
var ruleItems = production.RuleString.Split(':');
if (ruleItems.Length > 0)
{
operandNonTerminal = ruleItems[0].Trim();
}
}
if (operandNonTerminal != null && operationsByPrecedence.Count > 0)
{
GenerateExpressionParser(configuration, operandNonTerminal, operationsByPrecedence,
parserClass.Name);
}
}
result.Result = configuration;
return(result);
}
private static string GetOperandNonTerminal <IN, OUT>(Type parserClass, ParserConfiguration <IN, OUT> configuration,
BuildResult <ParserConfiguration <IN, OUT> > result) where IN : struct
{
List <MethodInfo> methods;
methods = parserClass.GetMethods().ToList();
var operandMethods = methods.Where(m =>
{
var attributes = m.GetCustomAttributes().ToList();
var attr = attributes.Find(a => a.GetType() == typeof(OperandAttribute));
return(attr != null);
}).ToList();
if (!operandMethods.Any())
{
result.AddError(new ParserInitializationError(ErrorLevel.FATAL, "missing [operand] attribute", ErrorCodes.PARSER_MISSING_OPERAND));
throw new Exception("missing [operand] attribute");
}
string operandNonTerminalName = null;
if (operandMethods.Count == 1)
{
var operandMethod = operandMethods.Single();
// TODO call GenerateExpressionParser with <ParserClassNAMe>_operand (or remove operand rule param ? )
operandNonTerminalName = GetNonTerminalNameFromProductionMethod <IN, OUT>(operandMethod);
}
else
{
// TODO 1 : generate <ParserClassNAMe>_operand production rule : operand : methods*
// rule.isexpression = true
// rule.isbypass = true
operandNonTerminalName = $"{parserClass.Name}_operand";
var operandNonTerminals = operandMethods.Select(x => GetNonTerminalNameFromProductionMethod <IN, OUT>(x));
var operandNonTerminal = new NonTerminal <IN>(operandNonTerminalName);
foreach (var operand in operandNonTerminals)
{
if (!string.IsNullOrEmpty(operand))
{
var rule = new Rule <IN>()
{
IsByPassRule = true,
IsExpressionRule = true,
Clauses = new List <IClause <IN> >()
{
new NonTerminalClause <IN>(operand)
}
};
operandNonTerminal.Rules.Add(rule);
}
}
configuration.NonTerminals[operandNonTerminalName] = operandNonTerminal;
}
return(operandNonTerminalName);
}
public EBNFSyntaxTreeVisitor(ParserConfiguration <IN, OUT> conf, object parserInstance) : base(conf,
parserInstance)
{
}
public static (bool foundRecursion, List <List <string> > recursions) CheckLeftRecursion(ParserConfiguration <IN, OUT> configuration)
{
List <List <string> > recursions = new List <List <string> >();
bool foundRecursion = false;
foreach (var nonTerminal in configuration.NonTerminals)
{
var(found, recursion) = CheckLeftRecursion(configuration, nonTerminal.Value, new List <string>()
{
nonTerminal.Key
});
if (found)
{
foundRecursion = true;
recursions.AddRange(recursion);
}
}
return(foundRecursion, recursions);
}
public static (bool recursionFound, List <List <string> > recursion) CheckLeftRecursion(ParserConfiguration <IN, OUT> configuration,
NonTerminal <IN> nonTerminal, List <string> currentPath)
{
var foundRecursion = false;
List <List <string> > recursions = new List <List <string> >();
var(found, path) = FindRecursion(currentPath);
if (found)
{
return(true, new List <List <string> >()
{
currentPath
});
}
var leftClauses = nonTerminal.Rules.SelectMany(x => GetLeftClausesName(x, configuration)).ToList();
foreach (var leftClause in leftClauses)
{
if (configuration.NonTerminals.ContainsKey(leftClause))
{
var newNonTerminal = configuration.NonTerminals[leftClause];
if (newNonTerminal != null)
{
var nPath = BuildPath(currentPath, leftClause);
var(foundRRuleRecursion, recursion) = CheckLeftRecursion(configuration, newNonTerminal, nPath);
if (foundRRuleRecursion)
{
foundRecursion = true;
recursions.AddRange(recursion);
}
}
}
else
{
;
}
}
return(foundRecursion, recursions);
}
public override BuildResult <Parser <IN, OUT> > BuildParser(object parserInstance, ParserType parserType,
string rootRule, BuildExtension <IN> extensionBuilder = null)
{
var ruleparser = new RuleParser <IN>();
var builder = new ParserBuilder <EbnfTokenGeneric, GrammarNode <IN> >();
var grammarParser = builder.BuildParser(ruleparser, ParserType.LL_RECURSIVE_DESCENT, "rule").Result;
var result = new BuildResult <Parser <IN, OUT> >();
ParserConfiguration <IN, OUT> configuration = null;
try
{
configuration = ExtractEbnfParserConfiguration(parserInstance.GetType(), grammarParser);
LeftRecursionChecker <IN, OUT> recursionChecker = new LeftRecursionChecker <IN, OUT>();
var(foundRecursion, recursions) = LeftRecursionChecker <IN, OUT> .CheckLeftRecursion(configuration);
if (foundRecursion)
{
var recs = string.Join("\n", recursions.Select(x => string.Join(" > ", x)));
result.AddError(new ParserInitializationError(ErrorLevel.FATAL, $"left recursion detected : {recs}", ErrorCodes.PARSER_LEFT_RECURSIVE));
return(result);
}
configuration.StartingRule = rootRule;
}
catch (Exception e)
{
result.AddError(new ParserInitializationError(ErrorLevel.ERROR, e.Message, ErrorCodes.PARSER_UNKNOWN_ERROR));
return(result);
}
var syntaxParser = BuildSyntaxParser(configuration, parserType, rootRule);
SyntaxTreeVisitor <IN, OUT> visitor = null;
if (parserType == ParserType.LL_RECURSIVE_DESCENT)
{
new SyntaxTreeVisitor <IN, OUT>(configuration, parserInstance);
}
else if (parserType == ParserType.EBNF_LL_RECURSIVE_DESCENT)
{
visitor = new EBNFSyntaxTreeVisitor <IN, OUT>(configuration, parserInstance);
}
var parser = new Parser <IN, OUT>(syntaxParser, visitor);
parser.Configuration = configuration;
var lexerResult = BuildLexer(extensionBuilder);
if (lexerResult.IsError)
{
foreach (var lexerResultError in lexerResult.Errors)
{
result.AddError(lexerResultError);
}
return(result);
}
else
{
parser.Lexer = lexerResult.Result;
}
parser.Instance = parserInstance;
result.Result = parser;
return(result);
}