/*---------------------------------------------------------------------- Compiler Generator Coco/R, Copyright (c) 1990, 2004 Hanspeter Moessenboeck, University of Linz extended by M. Loeberbauer & A. Woess, Univ. of Linz with improvements by Pat Terry, Rhodes University This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2, or (at your option) any later version. This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with this program; if not, write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. As an exception, it is allowed to write an extension of Coco/R that is used as a plugin in non-free software. If not otherwise stated, any source code generated by Coco/R (other than Coco/R itself) does not fall under the GNU General Public License. ----------------------------------------------------------------------*/ -->begin using System; -->namespace public class Parser { -->constants const bool T = true; const bool x = false; const int minErrDist = 2; public Scanner scanner; public Errors errors; public Token t; // last recognized token public Token la; // lookahead token int errDist = minErrDist; -->declarations public Parser(Scanner scanner) { this.scanner = scanner; errors = new Errors(); } void SynErr (int n) { if (errDist >= minErrDist) errors.SynErr(la.line, la.col, n); errDist = 0; } public void SemErr (string msg) { if (errDist >= minErrDist) errors.SemErr(t.line, t.col, msg); errDist = 0; } void Get () { for (;;) { t = la; la = scanner.Scan(); if (la.kind <= maxT) { ++errDist; break; } -->pragmas la = t; } } void Expect (int n) { if (la.kind==n) Get(); else { SynErr(n); } } bool StartOf (int s) { return set[s, la.kind]; } void ExpectWeak (int n, int follow) { if (la.kind == n) Get(); else { SynErr(n); while (!StartOf(follow)) Get(); } } bool WeakSeparator(int n, int syFol, int repFol) { int kind = la.kind; if (kind == n) {Get(); return true;} else if (StartOf(repFol)) {return false;} else { SynErr(n); while (!(set[syFol, kind] || set[repFol, kind] || set[0, kind])) { Get(); kind = la.kind; } return StartOf(syFol); } } -->productions public void Parse() { la = new Token(); la.val = ""; Get(); -->parseRoot } static readonly bool[,] set = { -->initialization }; } // end Parser public class Errors { public int count = 0; // number of errors detected public System.IO.TextWriter errorStream = Console.Out; // error messages go to this stream public string errMsgFormat = "-- line {0} col {1}: {2}"; // 0=line, 1=column, 2=text public virtual void SynErr (int line, int col, int n) { string s; switch (n) { -->errors default: s = "error " + n; break; } errorStream.WriteLine(errMsgFormat, line, col, s); count++; } public virtual void SemErr (int line, int col, string s) { errorStream.WriteLine(errMsgFormat, line, col, s); count++; } public virtual void SemErr (string s) { errorStream.WriteLine(s); count++; } public virtual void Warning (int line, int col, string s) { errorStream.WriteLine(errMsgFormat, line, col, s); } public virtual void Warning(string s) { errorStream.WriteLine(s); } } // Errors public class FatalError: Exception { public FatalError(string m): base(m) {} }