using System; using System.IO; using System.Collections; using System.Collections.Generic; using System.Text; using System.Diagnostics.Contracts; using Microsoft.Boogie; namespace Microsoft.Dafny { //----------------------------------------------------------------------------------- // Buffer //----------------------------------------------------------------------------------- public class Buffer { // This Buffer supports the following cases: // 1) seekable stream (file) // a) whole stream in buffer // b) part of stream in buffer // 2) non seekable stream (network, console) public const int EOF = 65535 + 1; // char.MaxValue + 1; const int MIN_BUFFER_LENGTH = 1024; // 1KB const int MAX_BUFFER_LENGTH = MIN_BUFFER_LENGTH * 64; // 64KB byte[]/*!*/ buf; // input buffer int bufStart; // position of first byte in buffer relative to input stream int bufLen; // length of buffer int fileLen; // length of input stream (may change if the stream is no file) int bufPos; // current position in buffer Stream/*!*/ stream; // input stream (seekable) bool isUserStream; // was the stream opened by the user? [ContractInvariantMethod] void ObjectInvariant(){ Contract.Invariant(buf != null); Contract.Invariant(stream != null); } // [NotDelayed] public Buffer (Stream/*!*/ s, bool isUserStream) : base() { Contract.Requires(s != null); stream = s; this.isUserStream = isUserStream; int fl, bl; if (s.CanSeek) { fl = (int) s.Length; bl = fl < MAX_BUFFER_LENGTH ? fl : MAX_BUFFER_LENGTH; // Math.Min(fileLen, MAX_BUFFER_LENGTH); bufStart = Int32.MaxValue; // nothing in the buffer so far } else { fl = bl = bufStart = 0; } buf = new byte[(bl>0) ? bl : MIN_BUFFER_LENGTH]; fileLen = fl; bufLen = bl; if (fileLen > 0) Pos = 0; // setup buffer to position 0 (start) else bufPos = 0; // index 0 is already after the file, thus Pos = 0 is invalid if (bufLen == fileLen && s.CanSeek) Close(); } protected Buffer(Buffer/*!*/ b) { // called in UTF8Buffer constructor Contract.Requires(b != null); buf = b.buf; bufStart = b.bufStart; bufLen = b.bufLen; fileLen = b.fileLen; bufPos = b.bufPos; stream = b.stream; // keep destructor from closing the stream //b.stream = null; isUserStream = b.isUserStream; // keep destructor from closing the stream b.isUserStream = true; } ~Buffer() { Close(); } protected void Close() { if (!isUserStream && stream != null) { stream.Close(); //stream = null; } } public virtual int Read () { if (bufPos < bufLen) { return buf[bufPos++]; } else if (Pos < fileLen) { Pos = Pos; // shift buffer start to Pos return buf[bufPos++]; } else if (stream != null && !stream.CanSeek && ReadNextStreamChunk() > 0) { return buf[bufPos++]; } else { return EOF; } } public int Peek () { int curPos = Pos; int ch = Read(); Pos = curPos; return ch; } public string/*!*/ GetString (int beg, int end) { Contract.Ensures(Contract.Result() != null); int len = 0; char[] buf = new char[end - beg]; int oldPos = Pos; Pos = beg; while (Pos < end) buf[len++] = (char) Read(); Pos = oldPos; return new String(buf, 0, len); } public int Pos { get { return bufPos + bufStart; } set { if (value >= fileLen && stream != null && !stream.CanSeek) { // Wanted position is after buffer and the stream // is not seek-able e.g. network or console, // thus we have to read the stream manually till // the wanted position is in sight. while (value >= fileLen && ReadNextStreamChunk() > 0); } if (value < 0 || value > fileLen) { throw new FatalError("buffer out of bounds access, position: " + value); } if (value >= bufStart && value < bufStart + bufLen) { // already in buffer bufPos = value - bufStart; } else if (stream != null) { // must be swapped in stream.Seek(value, SeekOrigin.Begin); bufLen = stream.Read(buf, 0, buf.Length); bufStart = value; bufPos = 0; } else { // set the position to the end of the file, Pos will return fileLen. bufPos = fileLen - bufStart; } } } // Read the next chunk of bytes from the stream, increases the buffer // if needed and updates the fields fileLen and bufLen. // Returns the number of bytes read. private int ReadNextStreamChunk() { int free = buf.Length - bufLen; if (free == 0) { // in the case of a growing input stream // we can neither seek in the stream, nor can we // foresee the maximum length, thus we must adapt // the buffer size on demand. byte[] newBuf = new byte[bufLen * 2]; Array.Copy(buf, newBuf, bufLen); buf = newBuf; free = bufLen; } int read = stream.Read(buf, bufLen, free); if (read > 0) { fileLen = bufLen = (bufLen + read); return read; } // end of stream reached return 0; } } //----------------------------------------------------------------------------------- // UTF8Buffer //----------------------------------------------------------------------------------- public class UTF8Buffer: Buffer { public UTF8Buffer(Buffer/*!*/ b): base(b) {Contract.Requires(b != null);} public override int Read() { int ch; do { ch = base.Read(); // until we find a utf8 start (0xxxxxxx or 11xxxxxx) } while ((ch >= 128) && ((ch & 0xC0) != 0xC0) && (ch != EOF)); if (ch < 128 || ch == EOF) { // nothing to do, first 127 chars are the same in ascii and utf8 // 0xxxxxxx or end of file character } else if ((ch & 0xF0) == 0xF0) { // 11110xxx 10xxxxxx 10xxxxxx 10xxxxxx int c1 = ch & 0x07; ch = base.Read(); int c2 = ch & 0x3F; ch = base.Read(); int c3 = ch & 0x3F; ch = base.Read(); int c4 = ch & 0x3F; ch = (((((c1 << 6) | c2) << 6) | c3) << 6) | c4; } else if ((ch & 0xE0) == 0xE0) { // 1110xxxx 10xxxxxx 10xxxxxx int c1 = ch & 0x0F; ch = base.Read(); int c2 = ch & 0x3F; ch = base.Read(); int c3 = ch & 0x3F; ch = (((c1 << 6) | c2) << 6) | c3; } else if ((ch & 0xC0) == 0xC0) { // 110xxxxx 10xxxxxx int c1 = ch & 0x1F; ch = base.Read(); int c2 = ch & 0x3F; ch = (c1 << 6) | c2; } return ch; } } //----------------------------------------------------------------------------------- // Scanner //----------------------------------------------------------------------------------- public class Scanner { const char EOL = '\n'; const int eofSym = 0; /* pdt */ const int maxT = 104; const int noSym = 104; [ContractInvariantMethod] void objectInvariant(){ Contract.Invariant(buffer!=null); Contract.Invariant(t != null); Contract.Invariant(start != null); Contract.Invariant(tokens != null); Contract.Invariant(pt != null); Contract.Invariant(tval != null); Contract.Invariant(Filename != null); Contract.Invariant(errorHandler != null); } public Buffer/*!*/ buffer; // scanner buffer Token/*!*/ t; // current token int ch; // current input character int pos; // byte position of current character int col; // column number of current character int line; // line number of current character int oldEols; // EOLs that appeared in a comment; static readonly Hashtable/*!*/ start; // maps first token character to start state Token/*!*/ tokens; // list of tokens already peeked (first token is a dummy) Token/*!*/ pt; // current peek token char[]/*!*/ tval = new char[128]; // text of current token int tlen; // length of current token private string/*!*/ Filename; private Errors/*!*/ errorHandler; static Scanner() { start = new Hashtable(128); for (int i = 39; i <= 39; ++i) start[i] = 1; for (int i = 63; i <= 63; ++i) start[i] = 1; for (int i = 65; i <= 90; ++i) start[i] = 1; for (int i = 92; i <= 92; ++i) start[i] = 1; for (int i = 95; i <= 95; ++i) start[i] = 1; for (int i = 98; i <= 122; ++i) start[i] = 1; for (int i = 48; i <= 57; ++i) start[i] = 7; for (int i = 34; i <= 34; ++i) start[i] = 8; start[97] = 10; start[123] = 17; start[125] = 18; start[61] = 57; start[124] = 58; start[59] = 19; start[44] = 20; start[58] = 59; start[60] = 60; start[62] = 61; start[40] = 21; start[41] = 22; start[42] = 23; start[96] = 24; start[91] = 26; start[93] = 27; start[46] = 62; start[8660] = 31; start[8658] = 33; start[38] = 34; start[8743] = 36; start[8744] = 38; start[33] = 63; start[8800] = 44; start[8804] = 45; start[8805] = 46; start[43] = 47; start[45] = 48; start[47] = 49; start[37] = 50; start[172] = 51; start[8704] = 53; start[8707] = 54; start[8226] = 56; start[Buffer.EOF] = -1; } // [NotDelayed] public Scanner (string/*!*/ fileName, Errors/*!*/ errorHandler) : base() { Contract.Requires(fileName != null); Contract.Requires(errorHandler != null); this.errorHandler = errorHandler; pt = tokens = new Token(); // first token is a dummy t = new Token(); // dummy because t is a non-null field try { Stream stream = new FileStream(fileName, FileMode.Open, FileAccess.Read, FileShare.Read); buffer = new Buffer(stream, false); Filename = fileName; Init(); } catch (IOException) { throw new FatalError("Cannot open file " + fileName); } } // [NotDelayed] public Scanner (Stream/*!*/ s, Errors/*!*/ errorHandler, string/*!*/ fileName) : base() { Contract.Requires(s != null); Contract.Requires(errorHandler != null); Contract.Requires(fileName != null); pt = tokens = new Token(); // first token is a dummy t = new Token(); // dummy because t is a non-null field buffer = new Buffer(s, true); this.errorHandler = errorHandler; this.Filename = fileName; Init(); } void Init() { pos = -1; line = 1; col = 0; oldEols = 0; NextCh(); if (ch == 0xEF) { // check optional byte order mark for UTF-8 NextCh(); int ch1 = ch; NextCh(); int ch2 = ch; if (ch1 != 0xBB || ch2 != 0xBF) { throw new FatalError(String.Format("illegal byte order mark: EF {0,2:X} {1,2:X}", ch1, ch2)); } buffer = new UTF8Buffer(buffer); col = 0; NextCh(); } pt = tokens = new Token(); // first token is a dummy } string/*!*/ ReadToEOL(){ Contract.Ensures(Contract.Result() != null); int p = buffer.Pos; int ch = buffer.Read(); // replace isolated '\r' by '\n' in order to make // eol handling uniform across Windows, Unix and Mac if (ch == '\r' && buffer.Peek() != '\n') ch = EOL; while (ch != EOL && ch != Buffer.EOF){ ch = buffer.Read(); // replace isolated '\r' by '\n' in order to make // eol handling uniform across Windows, Unix and Mac if (ch == '\r' && buffer.Peek() != '\n') ch = EOL; } string/*!*/ s = buffer.GetString(p, buffer.Pos); Contract.Assert(s!=null); return s; } void NextCh() { if (oldEols > 0) { ch = EOL; oldEols--; } else { // pos = buffer.Pos; // ch = buffer.Read(); col++; // // replace isolated '\r' by '\n' in order to make // // eol handling uniform across Windows, Unix and Mac // if (ch == '\r' && buffer.Peek() != '\n') ch = EOL; // if (ch == EOL) { line++; col = 0; } while (true) { pos = buffer.Pos; ch = buffer.Read(); col++; // replace isolated '\r' by '\n' in order to make // eol handling uniform across Windows, Unix and Mac if (ch == '\r' && buffer.Peek() != '\n') ch = EOL; if (ch == EOL) { line++; col = 0; } else if (ch == '#' && col == 1) { int prLine = line; int prColumn = 0; string/*!*/ hashLine = ReadToEOL(); Contract.Assert(hashLine!=null); col = 0; line++; hashLine = hashLine.TrimEnd(null); if (hashLine.StartsWith("line ") || hashLine == "line") { // parse #line pragma: #line num [filename] string h = hashLine.Substring(4).TrimStart(null); int x = h.IndexOf(' '); if (x == -1) { x = h.Length; // this will be convenient below when we look for a filename } try { int li = int.Parse(h.Substring(0, x)); h = h.Substring(x).Trim(); // act on #line line = li; if (h.Length != 0) { // a filename was specified Filename = h; } continue; // successfully parsed and acted on the #line pragma } catch (FormatException) { // just fall down through to produce an error message } this.errorHandler.SemErr(Filename, prLine, prColumn, "Malformed (#line num [filename]) pragma: #" + hashLine); continue; } this.errorHandler.SemErr(Filename, prLine, prColumn, "Unrecognized pragma: #" + hashLine); continue; } return; } } } void AddCh() { if (tlen >= tval.Length) { char[] newBuf = new char[2 * tval.Length]; Array.Copy(tval, 0, newBuf, 0, tval.Length); tval = newBuf; } if (ch != Buffer.EOF) { tval[tlen++] = (char) ch; NextCh(); } } bool Comment0() { int level = 1, pos0 = pos, line0 = line, col0 = col; NextCh(); if (ch == '/') { NextCh(); for(;;) { if (ch == 10) { level--; if (level == 0) { oldEols = line - line0; NextCh(); return true; } NextCh(); } else if (ch == Buffer.EOF) return false; else NextCh(); } } else { buffer.Pos = pos0; NextCh(); line = line0; col = col0; } return false; } bool Comment1() { int level = 1, pos0 = pos, line0 = line, col0 = col; NextCh(); if (ch == '*') { NextCh(); for(;;) { if (ch == '*') { NextCh(); if (ch == '/') { level--; if (level == 0) { oldEols = line - line0; NextCh(); return true; } NextCh(); } } else if (ch == '/') { NextCh(); if (ch == '*') { level++; NextCh(); } } else if (ch == Buffer.EOF) return false; else NextCh(); } } else { buffer.Pos = pos0; NextCh(); line = line0; col = col0; } return false; } void CheckLiteral() { switch (t.val) { case "module": t.kind = 5; break; case "imports": t.kind = 6; break; case "class": t.kind = 9; break; case "refines": t.kind = 10; break; case "ghost": t.kind = 11; break; case "static": t.kind = 12; break; case "unlimited": t.kind = 13; break; case "datatype": t.kind = 14; break; case "var": t.kind = 18; break; case "replaces": t.kind = 20; break; case "by": t.kind = 21; break; case "method": t.kind = 25; break; case "constructor": t.kind = 26; break; case "returns": t.kind = 27; break; case "modifies": t.kind = 28; break; case "free": t.kind = 29; break; case "requires": t.kind = 30; break; case "ensures": t.kind = 31; break; case "decreases": t.kind = 32; break; case "bool": t.kind = 35; break; case "nat": t.kind = 36; break; case "int": t.kind = 37; break; case "set": t.kind = 38; break; case "seq": t.kind = 39; break; case "object": t.kind = 40; break; case "function": t.kind = 41; break; case "reads": t.kind = 42; break; case "label": t.kind = 45; break; case "break": t.kind = 46; break; case "return": t.kind = 47; break; case "new": t.kind = 49; break; case "choose": t.kind = 53; break; case "if": t.kind = 54; break; case "else": t.kind = 55; break; case "case": t.kind = 56; break; case "while": t.kind = 58; break; case "invariant": t.kind = 59; break; case "match": t.kind = 60; break; case "foreach": t.kind = 61; break; case "in": t.kind = 62; break; case "assert": t.kind = 63; break; case "assume": t.kind = 64; break; case "print": t.kind = 65; break; case "false": t.kind = 89; break; case "true": t.kind = 90; break; case "null": t.kind = 91; break; case "this": t.kind = 92; break; case "fresh": t.kind = 93; break; case "allocated": t.kind = 94; break; case "old": t.kind = 95; break; case "then": t.kind = 96; break; case "forall": t.kind = 98; break; case "exists": t.kind = 100; break; default: break; } } Token/*!*/ NextToken() { Contract.Ensures(Contract.Result() != null); while (ch == ' ' || ch >= 9 && ch <= 10 || ch == 13 ) NextCh(); if (ch == '/' && Comment0() ||ch == '/' && Comment1()) return NextToken(); int recKind = noSym; int recEnd = pos; t = new Token(); t.pos = pos; t.col = col; t.line = line; t.filename = this.Filename; int state; if (start.ContainsKey(ch)) { Contract.Assert(start[ch] != null); state = (int) start[ch]; } else { state = 0; } tlen = 0; AddCh(); switch (state) { case -1: { t.kind = eofSym; break; } // NextCh already done case 0: { if (recKind != noSym) { tlen = recEnd - t.pos; SetScannerBehindT(); } t.kind = recKind; break; } // NextCh already done case 1: recEnd = pos; recKind = 1; if (ch == 39 || ch >= '0' && ch <= '9' || ch == '?' || ch >= 'A' && ch <= 'Z' || ch == 92 || ch == '_' || ch >= 'a' && ch <= 'z') {AddCh(); goto case 1;} else {t.kind = 1; t.val = new String(tval, 0, tlen); CheckLiteral(); return t;} case 2: recEnd = pos; recKind = 1; if (ch == 39 || ch >= '0' && ch <= '9' || ch == '?' || ch >= 'A' && ch <= 'Z' || ch == 92 || ch == '_' || ch >= 'a' && ch <= 'z') {AddCh(); goto case 2;} else {t.kind = 1; t.val = new String(tval, 0, tlen); CheckLiteral(); return t;} case 3: recEnd = pos; recKind = 1; if (ch == 39 || ch >= '0' && ch <= '9' || ch == '?' || ch >= 'A' && ch <= 'Z' || ch == 92 || ch == '_' || ch >= 'a' && ch <= 'z') {AddCh(); goto case 3;} else {t.kind = 1; t.val = new String(tval, 0, tlen); CheckLiteral(); return t;} case 4: recEnd = pos; recKind = 1; if (ch == 39 || ch >= '0' && ch <= '9' || ch == '?' || ch >= 'A' && ch <= 'Z' || ch == 92 || ch == '_' || ch >= 'a' && ch <= 'z') {AddCh(); goto case 4;} else {t.kind = 1; t.val = new String(tval, 0, tlen); CheckLiteral(); return t;} case 5: recEnd = pos; recKind = 1; if (ch == 39 || ch >= '0' && ch <= '9' || ch == '?' || ch >= 'A' && ch <= 'Z' || ch == 92 || ch == '_' || ch >= 'a' && ch <= 'z') {AddCh(); goto case 5;} else {t.kind = 1; t.val = new String(tval, 0, tlen); CheckLiteral(); return t;} case 6: recEnd = pos; recKind = 1; if (ch == 39 || ch >= '0' && ch <= '9' || ch == '?' || ch >= 'A' && ch <= 'Z' || ch == 92 || ch == '_' || ch >= 'a' && ch <= 'z') {AddCh(); goto case 6;} else {t.kind = 1; t.val = new String(tval, 0, tlen); CheckLiteral(); return t;} case 7: recEnd = pos; recKind = 2; if (ch >= '0' && ch <= '9') {AddCh(); goto case 7;} else {t.kind = 2; break;} case 8: if (ch == '"') {AddCh(); goto case 9;} else if (ch >= ' ' && ch <= '!' || ch >= '#' && ch <= '~') {AddCh(); goto case 8;} else {goto case 0;} case 9: {t.kind = 4; break;} case 10: recEnd = pos; recKind = 1; if (ch == 39 || ch >= '0' && ch <= '9' || ch == '?' || ch >= 'A' && ch <= 'Z' || ch == 92 || ch == '_' || ch >= 'a' && ch <= 'q' || ch >= 's' && ch <= 'z') {AddCh(); goto case 2;} else if (ch == 'r') {AddCh(); goto case 12;} else {t.kind = 1; t.val = new String(tval, 0, tlen); CheckLiteral(); return t;} case 11: recEnd = pos; recKind = 1; if (ch == 39 || ch >= '0' && ch <= '9' || ch == '?' || ch >= 'A' && ch <= 'Z' || ch == 92 || ch == '_' || ch >= 'a' && ch <= 'z') {AddCh(); goto case 11;} else {t.kind = 1; t.val = new String(tval, 0, tlen); CheckLiteral(); return t;} case 12: recEnd = pos; recKind = 1; if (ch == 39 || ch >= '0' && ch <= '9' || ch == '?' || ch >= 'A' && ch <= 'Z' || ch == 92 || ch == '_' || ch >= 'a' && ch <= 'q' || ch >= 's' && ch <= 'z') {AddCh(); goto case 3;} else if (ch == 'r') {AddCh(); goto case 13;} else {t.kind = 1; t.val = new String(tval, 0, tlen); CheckLiteral(); return t;} case 13: recEnd = pos; recKind = 1; if (ch == 39 || ch >= '0' && ch <= '9' || ch == '?' || ch >= 'A' && ch <= 'Z' || ch == 92 || ch == '_' || ch >= 'b' && ch <= 'z') {AddCh(); goto case 4;} else if (ch == 'a') {AddCh(); goto case 14;} else {t.kind = 1; t.val = new String(tval, 0, tlen); CheckLiteral(); return t;} case 14: recEnd = pos; recKind = 1; if (ch == 39 || ch >= '0' && ch <= '9' || ch == '?' || ch >= 'A' && ch <= 'Z' || ch == 92 || ch == '_' || ch >= 'a' && ch <= 'x' || ch == 'z') {AddCh(); goto case 5;} else if (ch == 'y') {AddCh(); goto case 15;} else {t.kind = 1; t.val = new String(tval, 0, tlen); CheckLiteral(); return t;} case 15: recEnd = pos; recKind = 3; if (ch == 39 || ch == '0' || ch == '?' || ch >= 'A' && ch <= 'Z' || ch == 92 || ch == '_' || ch >= 'a' && ch <= 'z') {AddCh(); goto case 6;} else if (ch >= '1' && ch <= '9') {AddCh(); goto case 16;} else {t.kind = 3; break;} case 16: recEnd = pos; recKind = 3; if (ch == 39 || ch == '?' || ch >= 'A' && ch <= 'Z' || ch == 92 || ch == '_' || ch >= 'a' && ch <= 'z') {AddCh(); goto case 11;} else if (ch >= '0' && ch <= '9') {AddCh(); goto case 16;} else {t.kind = 3; break;} case 17: {t.kind = 7; break;} case 18: {t.kind = 8; break;} case 19: {t.kind = 17; break;} case 20: {t.kind = 19; break;} case 21: {t.kind = 33; break;} case 22: {t.kind = 34; break;} case 23: {t.kind = 43; break;} case 24: {t.kind = 44; break;} case 25: {t.kind = 48; break;} case 26: {t.kind = 50; break;} case 27: {t.kind = 51; break;} case 28: {t.kind = 57; break;} case 29: if (ch == '>') {AddCh(); goto case 30;} else {goto case 0;} case 30: {t.kind = 66; break;} case 31: {t.kind = 67; break;} case 32: {t.kind = 68; break;} case 33: {t.kind = 69; break;} case 34: if (ch == '&') {AddCh(); goto case 35;} else {goto case 0;} case 35: {t.kind = 70; break;} case 36: {t.kind = 71; break;} case 37: {t.kind = 72; break;} case 38: {t.kind = 73; break;} case 39: {t.kind = 76; break;} case 40: {t.kind = 77; break;} case 41: {t.kind = 78; break;} case 42: if (ch == 'n') {AddCh(); goto case 43;} else {goto case 0;} case 43: {t.kind = 79; break;} case 44: {t.kind = 80; break;} case 45: {t.kind = 81; break;} case 46: {t.kind = 82; break;} case 47: {t.kind = 83; break;} case 48: {t.kind = 84; break;} case 49: {t.kind = 85; break;} case 50: {t.kind = 86; break;} case 51: {t.kind = 88; break;} case 52: {t.kind = 97; break;} case 53: {t.kind = 99; break;} case 54: {t.kind = 101; break;} case 55: {t.kind = 102; break;} case 56: {t.kind = 103; break;} case 57: recEnd = pos; recKind = 15; if (ch == '>') {AddCh(); goto case 28;} else if (ch == '=') {AddCh(); goto case 64;} else {t.kind = 15; break;} case 58: recEnd = pos; recKind = 16; if (ch == '|') {AddCh(); goto case 37;} else {t.kind = 16; break;} case 59: recEnd = pos; recKind = 22; if (ch == '=') {AddCh(); goto case 25;} else if (ch == ':') {AddCh(); goto case 55;} else {t.kind = 22; break;} case 60: recEnd = pos; recKind = 23; if (ch == '=') {AddCh(); goto case 65;} else {t.kind = 23; break;} case 61: recEnd = pos; recKind = 24; if (ch == '=') {AddCh(); goto case 39;} else {t.kind = 24; break;} case 62: recEnd = pos; recKind = 52; if (ch == '.') {AddCh(); goto case 52;} else {t.kind = 52; break;} case 63: recEnd = pos; recKind = 87; if (ch == '=') {AddCh(); goto case 40;} else if (ch == '!') {AddCh(); goto case 41;} else if (ch == 'i') {AddCh(); goto case 42;} else {t.kind = 87; break;} case 64: recEnd = pos; recKind = 74; if (ch == '>') {AddCh(); goto case 32;} else {t.kind = 74; break;} case 65: recEnd = pos; recKind = 75; if (ch == '=') {AddCh(); goto case 29;} else {t.kind = 75; break;} } t.val = new String(tval, 0, tlen); return t; } private void SetScannerBehindT() { buffer.Pos = t.pos; NextCh(); line = t.line; col = t.col; for (int i = 0; i < tlen; i++) NextCh(); } // get the next token (possibly a token already seen during peeking) public Token/*!*/ Scan () { Contract.Ensures(Contract.Result() != null); if (tokens.next == null) { return NextToken(); } else { pt = tokens = tokens.next; return tokens; } } // peek for the next token, ignore pragmas public Token/*!*/ Peek () { Contract.Ensures(Contract.Result() != null); do { if (pt.next == null) { pt.next = NextToken(); } pt = pt.next; } while (pt.kind > maxT); // skip pragmas return pt; } // make sure that peeking starts at the current scan position public void ResetPeek () { pt = tokens; } } // end Scanner public delegate void ErrorProc(int n, string filename, int line, int col); }