示例#1
0
        /// <summary>
        /// Raises an error on an unexepcted token
        /// </summary>
        /// <param name="stem">The size of the generation's stem</param>
        private void OnUnexpectedToken(int stem)
        {
            // build the list of expected terminals
            List <Symbol> expected = new List <Symbol>();
            GSSGeneration genData  = gss.GetGeneration();

            for (int i = 0; i != genData.Count; i++)
            {
                LRExpected expectedOnHead = parserAutomaton.GetExpected(gss.GetRepresentedState(i + genData.Start), lexer.Terminals);
                // register the terminals for shift actions
                foreach (Symbol terminal in expectedOnHead.Shifts)
                {
                    if (!expected.Contains(terminal))
                    {
                        expected.Add(terminal);
                    }
                }
                if (i < stem)
                {
                    // the state was in the stem, also look for reductions
                    foreach (Symbol terminal in expectedOnHead.Reductions)
                    {
                        if (!expected.Contains(terminal) && CheckIsExpected(i + genData.Start, terminal))
                        {
                            expected.Add(terminal);
                        }
                    }
                }
            }
            // register the error
            UnexpectedTokenError error = new UnexpectedTokenError(lexer.tokens[nextToken.Index], new ROList <Symbol>(expected));

            allErrors.Add(error);
#if !NETSTANDARD1_0
            if (ModeDebug)
            {
                Console.WriteLine("==== RNGLR parsing error:");
                Console.Write("\t");
                Console.WriteLine(error);
                TextContext context = lexer.Input.GetContext(error.Position);
                Console.Write("\t");
                Console.WriteLine(context.Content);
                Console.Write("\t");
                Console.WriteLine(context.Pointer);
                gss.Print();
            }
#endif
        }
示例#2
0
        /// <summary>
        /// Raises an error on an unexpected token
        /// </summary>
        /// <param name="kernel">The unexpected token's kernel</param>
        /// <returns>The next token kernel in the case the error is recovered</returns>
        private Lexer.TokenKernel OnUnexpectedToken(Lexer.TokenKernel kernel)
        {
            LRExpected expectedOnHead = automaton.GetExpected(stack[head], lexer.Terminals);
            // the terminals for shifts are always expected
            List <Symbol> expected = new List <Symbol>(expectedOnHead.Shifts);

            // check the terminals for reductions
            foreach (Symbol terminal in expectedOnHead.Reductions)
            {
                if (CheckIsExpected(terminal))
                {
                    expected.Add(terminal);
                }
            }
            // register the error
            allErrors.Add(new UnexpectedTokenError(lexer.tokens[kernel.Index], new ROList <Symbol>(expected)));
            // TODO: try to recover, or not
            return(new Lexer.TokenKernel(Symbol.SID_NOTHING, -1));
        }
示例#3
0
        /// <summary>
        /// Gets the expected terminals for the specified state
        /// </summary>
        /// <param name="state">The DFA state</param>
        /// <param name="terminals">The possible terminals</param>
        /// <returns>The expected terminals</returns>
        public LRExpected GetExpected(int state, ROList <Symbol> terminals)
        {
            LRExpected result = new LRExpected();
            int        offset = ncols * state;

            for (int i = 0; i != terminals.Count; i++)
            {
                LRAction action = table[offset];
                if (action.Code == LRActionCode.Shift)
                {
                    result.Shifts.Add(terminals[i]);
                }
                else if (action.Code == LRActionCode.Reduce)
                {
                    result.Reductions.Add(terminals[i]);
                }
                offset++;
            }
            return(result);
        }
示例#4
0
        /// <summary>
        /// Gets the expected terminals for the specified state
        /// </summary>
        /// <param name="state">The DFA state</param>
        /// <param name="terminals">The possible terminals</param>
        /// <returns>The expected terminals</returns>
        public LRExpected GetExpected(int state, ROList <Symbol> terminals)
        {
            LRExpected result = new LRExpected();

            for (int i = 0; i != terminals.Count; i++)
            {
                Cell cell = table[state * ncols + i];
                for (int j = 0; j != cell.ActionsCount; j++)
                {
                    LRAction action = actions[cell.ActionsIndex + j];
                    if (action.Code == LRActionCode.Shift)
                    {
                        result.AddUniqueShift(terminals[i]);
                    }
                    else if (action.Code == LRActionCode.Reduce)
                    {
                        result.AddUniqueReduction(terminals[i]);
                    }
                }
            }
            return(result);
        }