text: // Scintilla source code edit control
  /** @file LexVB.cxx
   ** Lexer for Visual Basic and VBScript.
   **/
  // Copyright 1998-2005 by Neil Hodgson <neilh@scintilla.org>
  // 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"
  
  #ifdef SCI_NAMESPACE
  using namespace Scintilla;
  #endif
  
  // Internal state, highlighted as number
  #define SCE_B_FILENUMBER SCE_B_DEFAULT+100
  
  
  static bool IsVBComment(Accessor &styler, Sci_Position pos, Sci_Position len) {
  	return len > 0 && styler[pos] == '\'';
  }
  
  static inline bool IsTypeCharacter(int ch) {
  	return ch == '%' || ch == '&' || ch == '@' || ch == '!' || ch == '#' || ch == '$';
  }
  
  // Extended to accept accented characters
  static inline bool IsAWordChar(int ch) {
  	return ch >= 0x80 ||
  	       (isalnum(ch) || ch == '.' || ch == '_');
  }
  
  static inline bool IsAWordStart(int ch) {
  	return ch >= 0x80 ||
  	       (isalpha(ch) || ch == '_');
  }
  
  static inline bool IsANumberChar(int ch) {
  	// Not exactly following number definition (several dots are seen as OK, etc.)
  	// but probably enough in most cases.
  	return (ch < 0x80) &&
  	        (isdigit(ch) || toupper(ch) == 'E' ||
               ch == '.' || ch == '-' || ch == '+');
  }
  
  static void ColouriseVBDoc(Sci_PositionU startPos, Sci_Position length, int initStyle,
                             WordList *keywordlists[], Accessor &styler, bool vbScriptSyntax) {
  
  	WordList &keywords = *keywordlists[0];
  	WordList &keywords2 = *keywordlists[1];
  	WordList &keywords3 = *keywordlists[2];
  	WordList &keywords4 = *keywordlists[3];
  
  	styler.StartAt(startPos);
  
  	int visibleChars = 0;
  	int fileNbDigits = 0;
  
  	// Do not leak onto next line
  	if (initStyle == SCE_B_STRINGEOL || initStyle == SCE_B_COMMENT || initStyle == SCE_B_PREPROCESSOR) {
  		initStyle = SCE_B_DEFAULT;
  	}
  
  	StyleContext sc(startPos, length, initStyle, styler);
  
  	for (; sc.More(); sc.Forward()) {
  
  		if (sc.state == SCE_B_OPERATOR) {
  			sc.SetState(SCE_B_DEFAULT);
  		} else if (sc.state == SCE_B_IDENTIFIER) {
  			if (!IsAWordChar(sc.ch)) {
  				// In Basic (except VBScript), a variable name or a function name
  				// can end with a special character indicating the type of the value
  				// held or returned.
  				bool skipType = false;
  				if (!vbScriptSyntax && IsTypeCharacter(sc.ch)) {
  					sc.Forward();	// Skip it
  					skipType = true;
  				}
  				if (sc.ch == ']') {
  					sc.Forward();
  				}
  				char s[100];
  				sc.GetCurrentLowered(s, sizeof(s));
  				if (skipType) {
  					s[strlen(s) - 1] = '\0';
  				}
  				if (strcmp(s, "rem") == 0) {
  					sc.ChangeState(SCE_B_COMMENT);
  				} else {
  					if (keywords.InList(s)) {
  						sc.ChangeState(SCE_B_KEYWORD);
  					} else if (keywords2.InList(s)) {
  						sc.ChangeState(SCE_B_KEYWORD2);
  					} else if (keywords3.InList(s)) {
  						sc.ChangeState(SCE_B_KEYWORD3);
  					} else if (keywords4.InList(s)) {
  						sc.ChangeState(SCE_B_KEYWORD4);
  					}	// Else, it is really an identifier...
  					sc.SetState(SCE_B_DEFAULT);
  				}
  			}
  		} else if (sc.state == SCE_B_NUMBER) {
  			// We stop the number definition on non-numerical non-dot non-eE non-sign char
  			// Also accepts A-F for hex. numbers
  			if (!IsANumberChar(sc.ch) && !(tolower(sc.ch) >= 'a' && tolower(sc.ch) <= 'f')) {
  				sc.SetState(SCE_B_DEFAULT);
  			}
  		} else if (sc.state == SCE_B_STRING) {
  			// VB doubles quotes to preserve them, so just end this string
  			// state now as a following quote will start again
  			if (sc.ch == '\"') {
  				if (sc.chNext == '\"') {
  					sc.Forward();
  				} else {
  					if (tolower(sc.chNext) == 'c') {
  						sc.Forward();
  					}
  					sc.ForwardSetState(SCE_B_DEFAULT);
  				}
  			} else if (sc.atLineEnd) {
  				visibleChars = 0;
  				sc.ChangeState(SCE_B_STRINGEOL);
  				sc.ForwardSetState(SCE_B_DEFAULT);
  			}
  		} else if (sc.state == SCE_B_COMMENT) {
  			if (sc.atLineEnd) {
  				visibleChars = 0;
  				sc.ForwardSetState(SCE_B_DEFAULT);
  			}
  		} else if (sc.state == SCE_B_PREPROCESSOR) {
  			if (sc.atLineEnd) {
  				visibleChars = 0;
  				sc.ForwardSetState(SCE_B_DEFAULT);
  			}
  		} else if (sc.state == SCE_B_FILENUMBER) {
  			if (IsADigit(sc.ch)) {
  				fileNbDigits++;
  				if (fileNbDigits > 3) {
  					sc.ChangeState(SCE_B_DATE);
  				}
  			} else if (sc.ch == '\r' || sc.ch == '\n' || sc.ch == ',') {
  				// Regular uses: Close #1; Put #1, ...; Get #1, ... etc.
  				// Too bad if date is format #27, Oct, 2003# or something like that...
  				// Use regular number state
  				sc.ChangeState(SCE_B_NUMBER);
  				sc.SetState(SCE_B_DEFAULT);
  			} else if (sc.ch == '#') {
  				sc.ChangeState(SCE_B_DATE);
  				sc.ForwardSetState(SCE_B_DEFAULT);
  			} else {
  				sc.ChangeState(SCE_B_DATE);
  			}
  			if (sc.state != SCE_B_FILENUMBER) {
  				fileNbDigits = 0;
  			}
  		} else if (sc.state == SCE_B_DATE) {
  			if (sc.atLineEnd) {
  				visibleChars = 0;
  				sc.ChangeState(SCE_B_STRINGEOL);
  				sc.ForwardSetState(SCE_B_DEFAULT);
  			} else if (sc.ch == '#') {
  				sc.ForwardSetState(SCE_B_DEFAULT);
  			}
  		}
  
  		if (sc.state == SCE_B_DEFAULT) {
  			if (sc.ch == '\'') {
  				sc.SetState(SCE_B_COMMENT);
  			} else if (sc.ch == '\"') {
  				sc.SetState(SCE_B_STRING);
  			} else if (sc.ch == '#' && visibleChars == 0) {
  				// Preprocessor commands are alone on their line
  				sc.SetState(SCE_B_PREPROCESSOR);
  			} else if (sc.ch == '#') {
  				// It can be a date literal, ending with #, or a file number, from 1 to 511
  				// The date literal depends on the locale, so anything can go between #'s.
  				// Can be #January 1, 1993# or #1 Jan 93# or #05/11/2003#, etc.
  				// So we set the FILENUMBER state, and switch to DATE if it isn't a file number
  				sc.SetState(SCE_B_FILENUMBER);
  			} else if (sc.ch == '&' && tolower(sc.chNext) == 'h') {
  				// Hexadecimal number
  				sc.SetState(SCE_B_NUMBER);
  				sc.Forward();
  			} else if (sc.ch == '&' && tolower(sc.chNext) == 'o') {
  				// Octal number
  				sc.SetState(SCE_B_NUMBER);
  				sc.Forward();
  			} else if (IsADigit(sc.ch) || (sc.ch == '.' && IsADigit(sc.chNext))) {
  				sc.SetState(SCE_B_NUMBER);
  			} else if (IsAWordStart(sc.ch) || (sc.ch == '[')) {
  				sc.SetState(SCE_B_IDENTIFIER);
  			} else if (isoperator(static_cast<char>(sc.ch)) || (sc.ch == '\\')) {	// Integer division
  				sc.SetState(SCE_B_OPERATOR);
  			}
  		}
  
  		if (sc.atLineEnd) {
  			visibleChars = 0;
  		}
  		if (!IsASpace(sc.ch)) {
  			visibleChars++;
  		}
  	}
  
  	if (sc.state == SCE_B_IDENTIFIER && !IsAWordChar(sc.ch)) {
  		// In Basic (except VBScript), a variable name or a function name
  		// can end with a special character indicating the type of the value
  		// held or returned.
  		bool skipType = false;
  		if (!vbScriptSyntax && IsTypeCharacter(sc.ch)) {
  			sc.Forward();	// Skip it
  			skipType = true;
  		}
  		if (sc.ch == ']') {
  			sc.Forward();
  		}
  		char s[100];
  		sc.GetCurrentLowered(s, sizeof(s));
  		if (skipType) {
  			s[strlen(s) - 1] = '\0';
  		}
  		if (strcmp(s, "rem") == 0) {
  			sc.ChangeState(SCE_B_COMMENT);
  		} else {
  			if (keywords.InList(s)) {
  				sc.ChangeState(SCE_B_KEYWORD);
  			} else if (keywords2.InList(s)) {
  				sc.ChangeState(SCE_B_KEYWORD2);
  			} else if (keywords3.InList(s)) {
  				sc.ChangeState(SCE_B_KEYWORD3);
  			} else if (keywords4.InList(s)) {
  				sc.ChangeState(SCE_B_KEYWORD4);
  			}	// Else, it is really an identifier...
  			sc.SetState(SCE_B_DEFAULT);
  		}
  	}
  
  	sc.Complete();
  }
  
  static void FoldVBDoc(Sci_PositionU startPos, Sci_Position length, int,
  						   WordList *[], Accessor &styler) {
  	Sci_Position endPos = startPos + length;
  
  	// Backtrack to previous line in case need to fix its fold status
  	Sci_Position lineCurrent = styler.GetLine(startPos);
  	if (startPos > 0) {
  		if (lineCurrent > 0) {
  			lineCurrent--;
  			startPos = styler.LineStart(lineCurrent);
  		}
  	}
  	int spaceFlags = 0;
  	int indentCurrent = styler.IndentAmount(lineCurrent, &spaceFlags, IsVBComment);
  	char chNext = styler[startPos];
  	for (Sci_Position i = startPos; i < endPos; i++) {
  		char ch = chNext;
  		chNext = styler.SafeGetCharAt(i + 1);
  
  		if ((ch == '\r' && chNext != '\n') || (ch == '\n') || (i == endPos)) {
  			int lev = indentCurrent;
  			int indentNext = styler.IndentAmount(lineCurrent + 1, &spaceFlags, IsVBComment);
  			if (!(indentCurrent & SC_FOLDLEVELWHITEFLAG)) {
  				// Only non whitespace lines can be headers
  				if ((indentCurrent & SC_FOLDLEVELNUMBERMASK) < (indentNext & SC_FOLDLEVELNUMBERMASK)) {
  					lev |= SC_FOLDLEVELHEADERFLAG;
  				} else if (indentNext & SC_FOLDLEVELWHITEFLAG) {
  					// Line after is blank so check the next - maybe should continue further?
  					int spaceFlags2 = 0;
  					int indentNext2 = styler.IndentAmount(lineCurrent + 2, &spaceFlags2, IsVBComment);
  					if ((indentCurrent & SC_FOLDLEVELNUMBERMASK) < (indentNext2 & SC_FOLDLEVELNUMBERMASK)) {
  						lev |= SC_FOLDLEVELHEADERFLAG;
  					}
  				}
  			}
  			indentCurrent = indentNext;
  			styler.SetLevel(lineCurrent, lev);
  			lineCurrent++;
  		}
  	}
  }
  
  static void ColouriseVBNetDoc(Sci_PositionU startPos, Sci_Position length, int initStyle,
                             WordList *keywordlists[], Accessor &styler) {
  	ColouriseVBDoc(startPos, length, initStyle, keywordlists, styler, false);
  }
  
  static void ColouriseVBScriptDoc(Sci_PositionU startPos, Sci_Position length, int initStyle,
                             WordList *keywordlists[], Accessor &styler) {
  	ColouriseVBDoc(startPos, length, initStyle, keywordlists, styler, true);
  }
  
  static const char * const vbWordListDesc[] = {
  	"Keywords",
  	"user1",
  	"user2",
  	"user3",
  	0
  };
  
  LexerModule lmVB(SCLEX_VB, ColouriseVBNetDoc, "vb", FoldVBDoc, vbWordListDesc);
  LexerModule lmVBScript(SCLEX_VBSCRIPT, ColouriseVBScriptDoc, "vbscript", FoldVBDoc, vbWordListDesc);
  
  