static CfgRule _Parse(ParseContext pc) { var result = new CfgRule(); pc.TrySkipWhiteSpace(); pc.ClearCapture(); pc.TryReadUntil(false, ' ', '\t', '\r', '\n', '\f', '\v', '-'); result.Left = pc.Capture; pc.TrySkipWhiteSpace(); pc.Expecting('-'); pc.Advance(); pc.Expecting('>'); pc.Advance(); while (-1 != pc.Current && '\n' != pc.Current) { pc.TrySkipWhiteSpace(); pc.ClearCapture(); pc.TryReadUntil(false, ' ', '\t', '\r', '\n', '\f', '\v'); result.Right.Add(pc.Capture); } return(result); }
static EbnfExpression _ParseExpression(EbnfDocument doc, ParseContext pc) { EbnfExpression current = null; EbnfExpression e; long position; int line; int column; pc.TrySkipCCommentsAndWhiteSpace(); position = pc.Position; line = pc.Line; column = pc.Column; while (-1 != pc.Current && ']' != pc.Current && ')' != pc.Current && '}' != pc.Current && ';' != pc.Current) { pc.TrySkipCCommentsAndWhiteSpace(); position = pc.Position; line = pc.Line; column = pc.Column; switch (pc.Current) { case '|': pc.Advance(); current = new EbnfOrExpression(current, _ParseExpression(doc, pc)); current.SetLocationInfo(line, column, position); break; case '(': pc.Advance(); e = _ParseExpression(doc, pc); current.SetLocationInfo(line, column, position); pc.Expecting(')'); pc.Advance(); e.SetLocationInfo(line, column, position); if (null == current) { current = e; } else { current = new EbnfConcatExpression(current, e); } break; case '[': pc.Advance(); e = new EbnfOptionalExpression(_ParseExpression(doc, pc)); e.SetLocationInfo(line, column, position); pc.TrySkipCCommentsAndWhiteSpace(); pc.Expecting(']'); pc.Advance(); if (null == current) { current = e; } else { current = new EbnfConcatExpression(current, e); } break; case '{': pc.Advance(); e = new EbnfRepeatExpression(_ParseExpression(doc, pc)); e.SetLocationInfo(line, column, position); pc.TrySkipCCommentsAndWhiteSpace(); pc.Expecting('}'); pc.Advance(); if ('+' == pc.Current) { pc.Advance(); ((EbnfRepeatExpression)e).IsOptional = false; } if (null == current) { current = e; } else { current = new EbnfConcatExpression(current, e); } break; case '\"': e = new EbnfLiteralExpression(pc.ParseJsonString()); if (null == current) { current = e; } else { current = new EbnfConcatExpression(current, e); } e.SetLocationInfo(line, column, position); break; case '\'': pc.Advance(); pc.ClearCapture(); pc.TryReadUntil('\'', '\\', false); pc.Expecting('\''); pc.Advance(); e = new EbnfRegexExpression(pc.Capture); if (null == current) { current = e; } else { current = new EbnfConcatExpression(current, e); } e.SetLocationInfo(line, column, position); break; case ';': case ']': case ')': case '}': return(current); default: e = new EbnfRefExpression(_ParseIdentifier(pc)); if (null == current) { current = e; } else { current = new EbnfConcatExpression(current, e); } e.SetLocationInfo(line, column, position); break; } } pc.TrySkipCCommentsAndWhiteSpace(); return(current); }
static CharFA <TAccept> _Parse(ParseContext pc, TAccept accept) { CharFA <TAccept> result = new CharFA <TAccept>(true, accept); CharFA <TAccept> f, next; int ch; pc.EnsureStarted(); var current = result; while (true) { switch (pc.Current) { case -1: return(result); case '.': pc.Advance(); f = current.FirstAcceptingState as CharFA <TAccept>; current = Set(new CharRange[] { new CharRange(char.MinValue, char.MaxValue) }, accept); switch (pc.Current) { case '*': current = Kleene(current, accept); pc.Advance(); break; case '+': current = Repeat(current, accept); pc.Advance(); break; case '?': current = Optional(current, accept); pc.Advance(); break; } f.IsAccepting = false; f.EpsilonTransitions.Add(current); break; case '\\': if (-1 != (ch = _ParseEscape(pc))) { next = null; switch (pc.Current) { case '*': next = new CharFA <TAccept>(); next.Transitions.Add((char)ch, new CharFA <TAccept>(true, accept)); next = Kleene(next, accept); pc.Advance(); break; case '+': next = new CharFA <TAccept>(); next.Transitions.Add((char)ch, new CharFA <TAccept>(true, accept)); next = Repeat(next, accept); pc.Advance(); break; case '?': next = new CharFA <TAccept>(); next.Transitions.Add((char)ch, new CharFA <TAccept>(true, accept)); next = Optional(next, accept); pc.Advance(); break; default: current = current.FirstAcceptingState as CharFA <TAccept>; current.IsAccepting = false; current.Transitions.Add((char)ch, new CharFA <TAccept>(true, accept)); break; } if (null != next) { current = current.FirstAcceptingState as CharFA <TAccept>; current.IsAccepting = false; current.EpsilonTransitions.Add(next); current = next; } } else { pc.Expecting(); // throw an error return(null); // doesn't execute } break; case ')': return(result); case '(': pc.Advance(); pc.Expecting(); f = current.FirstAcceptingState as CharFA <TAccept>; current = _Parse(pc, accept); pc.Expecting(')'); pc.Advance(); switch (pc.Current) { case '*': current = Kleene(current, accept); pc.Advance(); break; case '+': current = Repeat(current, accept); pc.Advance(); break; case '?': current = Optional(current, accept); pc.Advance(); break; } var ff = f.FirstAcceptingState; ff.EpsilonTransitions.Add(current); ff.IsAccepting = false; break; case '|': if (-1 != pc.Advance()) { current = _Parse(pc, accept); result = Or(new CharFA <TAccept>[] { result as CharFA <TAccept>, current as CharFA <TAccept> }, accept); } else { current = current.FirstAcceptingState as CharFA <TAccept>; result = Optional(result, accept); } break; case '[': pc.ClearCapture(); pc.Advance(); pc.Expecting(); bool not = false; if ('^' == pc.Current) { not = true; pc.Advance(); pc.Expecting(); } pc.TryReadUntil(']', '\\', false); pc.Expecting(']'); pc.Advance(); var r = (!not && "." == pc.Capture) ? new CharRange[] { new CharRange(char.MinValue, char.MaxValue) } : _ParseRanges(pc.Capture, true); if (not) { r = CharRange.NotRanges(r); } f = current.FirstAcceptingState as CharFA <TAccept>; current = Set(r, accept); switch (pc.Current) { case '*': current = Kleene(current, accept); pc.Advance(); break; case '+': current = Repeat(current, accept); pc.Advance(); break; case '?': current = Optional(current, accept); pc.Advance(); break; } f.IsAccepting = false; f.EpsilonTransitions.Add(current); break; default: ch = pc.Current; pc.Advance(); next = null; switch (pc.Current) { case '*': next = new CharFA <TAccept>(); next.Transitions.Add((char)ch, new CharFA <TAccept>(true, accept)); next = Kleene(next, accept); pc.Advance(); break; case '+': next = new CharFA <TAccept>(); next.Transitions.Add((char)ch, new CharFA <TAccept>(true, accept)); next = Repeat(next, accept); pc.Advance(); break; case '?': next = new CharFA <TAccept>(); next.Transitions.Add((char)ch, new CharFA <TAccept>(true, accept)); next = Optional(next, accept); pc.Advance(); break; default: current = current.FirstAcceptingState as CharFA <TAccept>; current.IsAccepting = false; current.Transitions.Add((char)ch, new CharFA <TAccept>(true, accept)); break; } if (null != next) { current = current.FirstAcceptingState as CharFA <TAccept>; current.IsAccepting = false; current.EpsilonTransitions.Add(next); current = next; } break; } } }
internal static RegexExpression Parse(ParseContext pc) { RegexExpression result = null, next = null; int ich; pc.EnsureStarted(); var line = pc.Line; var column = pc.Column; var position = pc.Position; while (true) { switch (pc.Current) { case -1: return(result); case '.': var nset = new RegexCharsetExpression(new RegexCharsetEntry[] { new RegexCharsetRangeEntry(char.MinValue, char.MaxValue) }, false); nset.SetLocation(line, column, position); if (null == result) { result = nset; } else { result = new RegexConcatExpression(result, nset); result.SetLocation(line, column, position); } pc.Advance(); result = _ParseModifier(result, pc); line = pc.Line; column = pc.Column; position = pc.Position; break; case '\\': if (-1 != (ich = _ParseEscape(pc))) { next = new RegexLiteralExpression((char)ich); next.SetLocation(line, column, position); next = _ParseModifier(next, pc); if (null != result) { result = new RegexConcatExpression(result, next); result.SetLocation(line, column, position); } else { result = next; } } else { pc.Expecting(); // throw an error return(null); // doesn't execute } line = pc.Line; column = pc.Column; position = pc.Position; break; case ')': return(result); case '(': pc.Advance(); pc.Expecting(); next = Parse(pc); pc.Expecting(')'); pc.Advance(); next = _ParseModifier(next, pc); if (null == result) { result = next; } else { result = new RegexConcatExpression(result, next); result.SetLocation(line, column, position); } line = pc.Line; column = pc.Column; position = pc.Position; break; case '|': if (-1 != pc.Advance()) { next = Parse(pc); result = new RegexOrExpression(result, next); result.SetLocation(line, column, position); } else { result = new RegexOrExpression(result, null); result.SetLocation(line, column, position); } line = pc.Line; column = pc.Column; position = pc.Position; break; case '[': pc.ClearCapture(); pc.Advance(); pc.Expecting(); bool not = false; if ('^' == pc.Current) { not = true; pc.Advance(); pc.Expecting(); } var ranges = _ParseRanges(pc); if (ranges.Count == 0) { System.Diagnostics.Debugger.Break(); } pc.Expecting(']'); pc.Advance(); next = new RegexCharsetExpression(ranges, not); next.SetLocation(line, column, position); next = _ParseModifier(next, pc); if (null == result) { result = next; } else { result = new RegexConcatExpression(result, next); result.SetLocation(pc.Line, pc.Column, pc.Position); } line = pc.Line; column = pc.Column; position = pc.Position; break; default: ich = pc.Current; next = new RegexLiteralExpression((char)ich); next.SetLocation(line, column, position); pc.Advance(); next = _ParseModifier(next, pc); if (null == result) { result = next; } else { result = new RegexConcatExpression(result, next); result.SetLocation(line, column, position); } line = pc.Line; column = pc.Column; position = pc.Position; break; } } }