text: // Scintilla source code edit control
  /** @file LexRebol.cxx
   ** Lexer for REBOL.
   ** Written by Pascal Hurni, inspired from LexLua by Paul Winwood & Marcos E. Wurzius & Philippe Lhoste
   **
   ** History:
   **		2005-04-07	First release.
   **		2005-04-10	Closing parens and brackets go now in default style
   **					String and comment nesting should be more safe
   **/
  // Copyright 2005 by Pascal Hurni <pascal_hurni@fastmail.fm>
  // The License.txt file describes the conditions under which this software may be distributed.
  
  #include <stdlib.h>
  #include <string.h>
  #include <stdio.h>
  #include <stdarg.h>
  #include <assert.h>
  #include <ctype.h>
  
  #include "ILexer.h"
  #include "Scintilla.h"
  #include "SciLexer.h"
  
  #include "WordList.h"
  #include "LexAccessor.h"
  #include "Accessor.h"
  #include "StyleContext.h"
  #include "CharacterSet.h"
  #include "LexerModule.h"
  
  using namespace Scintilla;
  
  static inline bool IsAWordChar(const int ch) {
  	return (isalnum(ch) || ch == '?' || ch == '!' || ch == '.' || ch == '\'' || ch == '+' || ch == '-' || ch == '*' || ch == '&' || ch == '|' || ch == '=' || ch == '_' || ch == '~');
  }
  
  static inline bool IsAWordStart(const int ch, const int ch2) {
  	return ((ch == '+' || ch == '-' || ch == '.') && !isdigit(ch2)) ||
  		(isalpha(ch) || ch == '?' || ch == '!' || ch == '\'' || ch == '*' || ch == '&' || ch == '|' || ch == '=' || ch == '_' || ch == '~');
  }
  
  static inline bool IsAnOperator(const int ch, const int ch2, const int ch3) {
  	// One char operators
  	if (IsASpaceOrTab(ch2)) {
  		return ch == '+' || ch == '-' || ch == '*' || ch == '/' || ch == '<' || ch == '>' || ch == '=' || ch == '?';
  	}
  
  	// Two char operators
  	if (IsASpaceOrTab(ch3)) {
  		return (ch == '*' && ch2 == '*') ||
  			   (ch == '/' && ch2 == '/') ||
  			   (ch == '<' && (ch2 == '=' || ch2 == '>')) ||
  			   (ch == '>' && ch2 == '=') ||
  			   (ch == '=' && (ch2 == '=' || ch2 == '?')) ||
  			   (ch == '?' && ch2 == '?');
  	}
  
  	return false;
  }
  
  static inline bool IsBinaryStart(const int ch, const int ch2, const int ch3, const int ch4) {
  	return (ch == '#' && ch2 == '{') ||
  		   (IsADigit(ch) && ch2 == '#' && ch3 == '{' ) ||
  		   (IsADigit(ch) && IsADigit(ch2) && ch3 == '#' && ch4 == '{' );
  }
  
  
  static void ColouriseRebolDoc(Sci_PositionU startPos, Sci_Position length, int initStyle, WordList *keywordlists[], Accessor &styler) {
  
  	WordList &keywords = *keywordlists[0];
  	WordList &keywords2 = *keywordlists[1];
  	WordList &keywords3 = *keywordlists[2];
  	WordList &keywords4 = *keywordlists[3];
  	WordList &keywords5 = *keywordlists[4];
  	WordList &keywords6 = *keywordlists[5];
  	WordList &keywords7 = *keywordlists[6];
  	WordList &keywords8 = *keywordlists[7];
  
  	Sci_Position currentLine = styler.GetLine(startPos);
  	// Initialize the braced string {.. { ... } ..} nesting level, if we are inside such a string.
  	int stringLevel = 0;
  	if (initStyle == SCE_REBOL_BRACEDSTRING || initStyle == SCE_REBOL_COMMENTBLOCK) {
  		stringLevel = styler.GetLineState(currentLine - 1);
  	}
  
  	bool blockComment = initStyle == SCE_REBOL_COMMENTBLOCK;
  	int dotCount = 0;
  
  	// Do not leak onto next line
  	if (initStyle == SCE_REBOL_COMMENTLINE) {
  		initStyle = SCE_REBOL_DEFAULT;
  	}
  
  	StyleContext sc(startPos, length, initStyle, styler);
  	if (startPos == 0) {
  		sc.SetState(SCE_REBOL_PREFACE);
  	}
  	for (; sc.More(); sc.Forward()) {
  
  		//--- What to do at line end ?
  		if (sc.atLineEnd) {
  			// Can be either inside a {} string or simply at eol
  			if (sc.state != SCE_REBOL_BRACEDSTRING && sc.state != SCE_REBOL_COMMENTBLOCK &&
  				sc.state != SCE_REBOL_BINARY && sc.state != SCE_REBOL_PREFACE)
  				sc.SetState(SCE_REBOL_DEFAULT);
  
  			// Update the line state, so it can be seen by next line
  			currentLine = styler.GetLine(sc.currentPos);
  			switch (sc.state) {
  			case SCE_REBOL_BRACEDSTRING:
  			case SCE_REBOL_COMMENTBLOCK:
  				// Inside a braced string, we set the line state
  				styler.SetLineState(currentLine, stringLevel);
  				break;
  			default:
  				// Reset the line state
  				styler.SetLineState(currentLine, 0);
  				break;
  			}
  
  			// continue with next char
  			continue;
  		}
  
  		//--- What to do on white-space ?
  		if (IsASpaceOrTab(sc.ch))
  		{
  			// Return to default if any of these states
  			if (sc.state == SCE_REBOL_OPERATOR || sc.state == SCE_REBOL_CHARACTER ||
  				sc.state == SCE_REBOL_NUMBER || sc.state == SCE_REBOL_PAIR ||
  				sc.state == SCE_REBOL_TUPLE || sc.state == SCE_REBOL_FILE ||
  				sc.state == SCE_REBOL_DATE || sc.state == SCE_REBOL_TIME ||
  				sc.state == SCE_REBOL_MONEY || sc.state == SCE_REBOL_ISSUE ||
  				sc.state == SCE_REBOL_URL || sc.state == SCE_REBOL_EMAIL) {
  				sc.SetState(SCE_REBOL_DEFAULT);
  			}
  		}
  
  		//--- Specialize state ?
  		// URL, Email look like identifier
  		if (sc.state == SCE_REBOL_IDENTIFIER)
  		{
  			if (sc.ch == ':' && !IsASpace(sc.chNext)) {
  				sc.ChangeState(SCE_REBOL_URL);
  			} else if (sc.ch == '@') {
  				sc.ChangeState(SCE_REBOL_EMAIL);
  			} else if (sc.ch == '$') {
  				sc.ChangeState(SCE_REBOL_MONEY);
  			}
  		}
  		// Words look like identifiers
  		if (sc.state == SCE_REBOL_IDENTIFIER || (sc.state >= SCE_REBOL_WORD && sc.state <= SCE_REBOL_WORD8)) {
  			// Keywords ?
  			if (!IsAWordChar(sc.ch) || sc.Match('/')) {
  				char s[100];
  				sc.GetCurrentLowered(s, sizeof(s));
  				blockComment = strcmp(s, "comment") == 0;
  				if (keywords8.InList(s)) {
  					sc.ChangeState(SCE_REBOL_WORD8);
  				} else if (keywords7.InList(s)) {
  					sc.ChangeState(SCE_REBOL_WORD7);
  				} else if (keywords6.InList(s)) {
  					sc.ChangeState(SCE_REBOL_WORD6);
  				} else if (keywords5.InList(s)) {
  					sc.ChangeState(SCE_REBOL_WORD5);
  				} else if (keywords4.InList(s)) {
  					sc.ChangeState(SCE_REBOL_WORD4);
  				} else if (keywords3.InList(s)) {
  					sc.ChangeState(SCE_REBOL_WORD3);
  				} else if (keywords2.InList(s)) {
  					sc.ChangeState(SCE_REBOL_WORD2);
  				} else if (keywords.InList(s)) {
  					sc.ChangeState(SCE_REBOL_WORD);
  				}
  				// Keep same style if there are refinements
  				if (!sc.Match('/')) {
  					sc.SetState(SCE_REBOL_DEFAULT);
  				}
  			}
  		// special numbers
  		} else if (sc.state == SCE_REBOL_NUMBER) {
  			switch (sc.ch) {
  			case 'x':	sc.ChangeState(SCE_REBOL_PAIR);
  						break;
  			case ':':	sc.ChangeState(SCE_REBOL_TIME);
  						break;
  			case '-':
  			case '/':	sc.ChangeState(SCE_REBOL_DATE);
  						break;
  			case '.':	if (++dotCount >= 2) sc.ChangeState(SCE_REBOL_TUPLE);
  						break;
  			}
  		}
  
  		//--- Determine if the current state should terminate
  		if (sc.state == SCE_REBOL_QUOTEDSTRING || sc.state == SCE_REBOL_CHARACTER) {
  			if (sc.ch == '^' && sc.chNext == '\"') {
  				sc.Forward();
  			} else if (sc.ch == '\"') {
  				sc.ForwardSetState(SCE_REBOL_DEFAULT);
  			}
  		} else if (sc.state == SCE_REBOL_BRACEDSTRING || sc.state == SCE_REBOL_COMMENTBLOCK) {
  			if (sc.ch == '}') {
  				if (--stringLevel == 0) {
  					sc.ForwardSetState(SCE_REBOL_DEFAULT);
  				}
  			} else if (sc.ch == '{') {
  				stringLevel++;
  			}
  		} else if (sc.state == SCE_REBOL_BINARY) {
  			if (sc.ch == '}') {
  				sc.ForwardSetState(SCE_REBOL_DEFAULT);
  			}
  		} else if (sc.state == SCE_REBOL_TAG) {
  			if (sc.ch == '>') {
  				sc.ForwardSetState(SCE_REBOL_DEFAULT);
  			}
  		} else if (sc.state == SCE_REBOL_PREFACE) {
  			if (sc.MatchIgnoreCase("rebol"))
  			{
  				int i;
  				for (i=5; IsASpaceOrTab(styler.SafeGetCharAt(sc.currentPos+i, 0)); i++);
  				if (sc.GetRelative(i) == '[')
  					sc.SetState(SCE_REBOL_DEFAULT);
  			}
  		}
  
  		//--- Parens and bracket changes to default style when the current is a number
  		if (sc.state == SCE_REBOL_NUMBER || sc.state == SCE_REBOL_PAIR || sc.state == SCE_REBOL_TUPLE ||
  			sc.state == SCE_REBOL_MONEY || sc.state == SCE_REBOL_ISSUE || sc.state == SCE_REBOL_EMAIL ||
  			sc.state == SCE_REBOL_URL || sc.state == SCE_REBOL_DATE || sc.state == SCE_REBOL_TIME) {
  			if (sc.ch == '(' || sc.ch == '[' || sc.ch == ')' || sc.ch == ']') {
  				sc.SetState(SCE_REBOL_DEFAULT);
  			}
  		}
  
  		//--- Determine if a new state should be entered.
  		if (sc.state == SCE_REBOL_DEFAULT) {
  			if (IsAnOperator(sc.ch, sc.chNext, sc.GetRelative(2))) {
  				sc.SetState(SCE_REBOL_OPERATOR);
  			} else if (IsBinaryStart(sc.ch, sc.chNext, sc.GetRelative(2), sc.GetRelative(3))) {
  				sc.SetState(SCE_REBOL_BINARY);
  			} else if (IsAWordStart(sc.ch, sc.chNext)) {
  				sc.SetState(SCE_REBOL_IDENTIFIER);
  			} else if (IsADigit(sc.ch) || sc.ch == '+' || sc.ch == '-' || /*Decimal*/ sc.ch == '.' || sc.ch == ',') {
  				dotCount = 0;
  				sc.SetState(SCE_REBOL_NUMBER);
  			} else if (sc.ch == '\"') {
  				sc.SetState(SCE_REBOL_QUOTEDSTRING);
  			} else if (sc.ch == '{') {
  				sc.SetState(blockComment ? SCE_REBOL_COMMENTBLOCK : SCE_REBOL_BRACEDSTRING);
  				++stringLevel;
  			} else if (sc.ch == ';') {
  				sc.SetState(SCE_REBOL_COMMENTLINE);
  			} else if (sc.ch == '$') {
  				sc.SetState(SCE_REBOL_MONEY);
  			} else if (sc.ch == '%') {
  				sc.SetState(SCE_REBOL_FILE);
  			} else if (sc.ch == '<') {
  				sc.SetState(SCE_REBOL_TAG);
  			} else if (sc.ch == '#' && sc.chNext == '"') {
  				sc.SetState(SCE_REBOL_CHARACTER);
  				sc.Forward();
  			} else if (sc.ch == '#' && sc.chNext != '"' && sc.chNext != '{' ) {
  				sc.SetState(SCE_REBOL_ISSUE);
  			}
  		}
  	}
  	sc.Complete();
  }
  
  
  static void FoldRebolDoc(Sci_PositionU startPos, Sci_Position length, int /* initStyle */, WordList *[],
                              Accessor &styler) {
  	Sci_PositionU lengthDoc = startPos + length;
  	int visibleChars = 0;
  	Sci_Position lineCurrent = styler.GetLine(startPos);
  	int levelPrev = styler.LevelAt(lineCurrent) & SC_FOLDLEVELNUMBERMASK;
  	int levelCurrent = levelPrev;
  	char chNext = styler[startPos];
  	int styleNext = styler.StyleAt(startPos);
  	for (Sci_PositionU i = startPos; i < lengthDoc; i++) {
  		char ch = chNext;
  		chNext = styler.SafeGetCharAt(i + 1);
  		int style = styleNext;
  		styleNext = styler.StyleAt(i + 1);
  		bool atEOL = (ch == '\r' && chNext != '\n') || (ch == '\n');
  		if (style == SCE_REBOL_DEFAULT) {
  			if (ch == '[') {
  				levelCurrent++;
  			} else if (ch == ']') {
  				levelCurrent--;
  			}
  		}
  		if (atEOL) {
  			int lev = levelPrev;
  			if (visibleChars == 0)
  				lev |= SC_FOLDLEVELWHITEFLAG;
  			if ((levelCurrent > levelPrev) && (visibleChars > 0))
  				lev |= SC_FOLDLEVELHEADERFLAG;
  			if (lev != styler.LevelAt(lineCurrent)) {
  				styler.SetLevel(lineCurrent, lev);
  			}
  			lineCurrent++;
  			levelPrev = levelCurrent;
  			visibleChars = 0;
  		}
  		if (!isspacechar(ch))
  			visibleChars++;
  	}
  	// Fill in the real level of the next line, keeping the current flags as they will be filled in later
  	int flagsNext = styler.LevelAt(lineCurrent) & ~SC_FOLDLEVELNUMBERMASK;
  	styler.SetLevel(lineCurrent, levelPrev | flagsNext);
  }
  
  static const char * const rebolWordListDesc[] = {
  	"Keywords",
  	0
  };
  
  LexerModule lmREBOL(SCLEX_REBOL, ColouriseRebolDoc, "rebol", FoldRebolDoc, rebolWordListDesc);
  
  