Folding features added by Udo Lechner.

Explicit fold points which can be set to arbitrary strings and occur anywhere.
Can choose whether to have syntax based folding and multiline comment folding.

5 files changed, 296 insertions, 23 deletions

diff --git a/include/SciLexer.h b/include/SciLexer.h
index 118e3927e..627e6014e 100644
--- a/include/SciLexer.h
+++ b/include/SciLexer.h
@@ -604,6 +604,7 @@
 #define SCE_ASM_CHARACTER 12
 #define SCE_ASM_STRINGEOL 13
 #define SCE_ASM_EXTINSTRUCTION 14
+#define SCE_ASM_COMMENTDIRECTIVE 15
 #define SCE_F_DEFAULT 0
 #define SCE_F_COMMENT 1
 #define SCE_F_NUMBER 2
diff --git a/include/Scintilla.iface b/include/Scintilla.iface
index c78a0e6e5..d4cf22770 100644
--- a/include/Scintilla.iface
+++ b/include/Scintilla.iface
@@ -2917,6 +2917,7 @@ val SCE_ASM_COMMENTBLOCK=11
 val SCE_ASM_CHARACTER=12
 val SCE_ASM_STRINGEOL=13
 val SCE_ASM_EXTINSTRUCTION=14
+val SCE_ASM_COMMENTDIRECTIVE=15
 # Lexical states for SCLEX_FORTRAN
 lex Fortran=SCLEX_FORTRAN SCE_F_
 lex F77=SCLEX_F77 SCE_F_
diff --git a/lexers/LexAsm.cxx b/lexers/LexAsm.cxx
index b00420945..47ed4bb86 100644
--- a/lexers/LexAsm.cxx
+++ b/lexers/LexAsm.cxx
@@ -4,17 +4,17 @@
  ** Written by The Black Horus
  ** Enhancements and NASM stuff by Kein-Hong Man, 2003-10
  ** SCE_ASM_COMMENTBLOCK and SCE_ASM_CHARACTER are for future GNU as colouring
- ** Converted to lexer object by "Udo Lechner" <dlchnr(at)gmx(dot)net>
+ ** Converted to lexer object and added further folding features/properties by "Udo Lechner" <dlchnr(at)gmx(dot)net>
  **/
 // Copyright 1998-2003 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 <ctype.h>
 #include <stdio.h>
 #include <stdarg.h>
 #include <assert.h>
+#include <ctype.h>
 
 #ifdef _MSC_VER
 #pragma warning(disable: 4786)
@@ -22,6 +22,7 @@
 
 #include <string>
 #include <map>
+#include <set>
 
 #include "ILexer.h"
 #include "Scintilla.h"
@@ -29,7 +30,6 @@
 
 #include "WordList.h"
 #include "LexAccessor.h"
-#include "Accessor.h"
 #include "StyleContext.h"
 #include "CharacterSet.h"
 #include "LexerModule.h"
@@ -62,11 +62,39 @@ static inline bool IsAsmOperator(const int ch) {
 	return false;
 }
 
+static bool IsStreamCommentStyle(int style) {
+	return style == SCE_ASM_COMMENTDIRECTIVE || style == SCE_ASM_COMMENTBLOCK;
+}
+
+static inline int LowerCase(int c) {
+	if (c >= 'A' && c <= 'Z')
+		return 'a' + c - 'A';
+	return c;
+}
+
 // An individual named option for use in an OptionSet
 
 // Options used for LexerAsm
 struct OptionsAsm {
+	std::string delimiter;
+	bool fold;
+	bool foldSyntaxBased;
+	bool foldCommentMultiline;
+	bool foldCommentExplicit;
+	std::string foldExplicitStart;
+	std::string foldExplicitEnd;
+	bool foldExplicitAnywhere;
+	bool foldCompact;
 	OptionsAsm() {
+		delimiter = "";
+		fold = false;
+		foldSyntaxBased = true;
+		foldCommentMultiline = false;
+		foldCommentExplicit = false;
+		foldExplicitStart = "";
+		foldExplicitEnd   = "";
+		foldExplicitAnywhere = false;
+		foldCompact = true;
 	}
 };
 
@@ -77,11 +105,40 @@ static const char * const asmWordListDesc[] = {
 	"Directives",
 	"Directive operands",
 	"Extended instructions",
+	"Directives4Foldstart",
+	"Directives4Foldend",
 	0
 };
 
 struct OptionSetAsm : public OptionSet<OptionsAsm> {
 	OptionSetAsm() {
+		DefineProperty("lexer.asm.comment.delimiter", &OptionsAsm::delimiter,
+			"Character used for COMMENT directive's delimiter, replacing the standard \"~\".");
+
+		DefineProperty("fold", &OptionsAsm::fold);
+
+		DefineProperty("fold.asm.syntax.based", &OptionsAsm::foldSyntaxBased,
+			"Set this property to 0 to disable syntax based folding.");
+
+		DefineProperty("fold.asm.comment.multiline", &OptionsAsm::foldCommentMultiline,
+			"Set this property to 1 to enable folding multi-line comments.");
+
+		DefineProperty("fold.asm.comment.explicit", &OptionsAsm::foldCommentExplicit,
+			"This option enables folding explicit fold points when using the Asm lexer. "
+			"Explicit fold points allows adding extra folding by placing a ;{ comment at the start and a ;} "
+			"at the end of a section that should fold.");
+
+		DefineProperty("fold.asm.explicit.start", &OptionsAsm::foldExplicitStart,
+			"The string to use for explicit fold start points, replacing the standard ;{.");
+
+		DefineProperty("fold.asm.explicit.end", &OptionsAsm::foldExplicitEnd,
+			"The string to use for explicit fold end points, replacing the standard ;}.");
+
+		DefineProperty("fold.asm.explicit.anywhere", &OptionsAsm::foldExplicitAnywhere,
+			"Set this property to 1 to enable explicit fold points anywhere, not just in line comments.");
+
+		DefineProperty("fold.compact", &OptionsAsm::foldCompact);
+
 		DefineWordListSets(asmWordListDesc);
 	}
 };
@@ -93,6 +150,8 @@ class LexerAsm : public ILexer {
 	WordList directive;
 	WordList directiveOperand;
 	WordList extInstruction;
+	WordList directives4foldstart;
+	WordList directives4foldend;
 	OptionsAsm options;
 	OptionSetAsm osAsm;
 public:
@@ -160,6 +219,12 @@ int SCI_METHOD LexerAsm::WordListSet(int n, const char *wl) {
 	case 5:
 		wordListN = &extInstruction;
 		break;
+	case 6:
+		wordListN = &directives4foldstart;
+		break;
+	case 7:
+		wordListN = &directives4foldend;
+		break;
 	}
 	int firstModification = -1;
 	if (wordListN) {
@@ -208,7 +273,7 @@ void SCI_METHOD LexerAsm::Lex(unsigned int startPos, int length, int initStyle,
 			if (!IsAsmOperator(sc.ch)) {
 			    sc.SetState(SCE_ASM_DEFAULT);
 			}
-		}else if (sc.state == SCE_ASM_NUMBER) {
+		} else if (sc.state == SCE_ASM_NUMBER) {
 			if (!IsAWordChar(sc.ch)) {
 				sc.SetState(SCE_ASM_DEFAULT);
 			}
@@ -216,6 +281,7 @@ void SCI_METHOD LexerAsm::Lex(unsigned int startPos, int length, int initStyle,
 			if (!IsAWordChar(sc.ch) ) {
 				char s[100];
 				sc.GetCurrentLowered(s, sizeof(s));
+				bool IsDirective = false;
 
 				if (cpuInstruction.InList(s)) {
 					sc.ChangeState(SCE_ASM_CPUINSTRUCTION);
@@ -225,15 +291,32 @@ void SCI_METHOD LexerAsm::Lex(unsigned int startPos, int length, int initStyle,
 					sc.ChangeState(SCE_ASM_REGISTER);
 				}  else if (directive.InList(s)) {
 					sc.ChangeState(SCE_ASM_DIRECTIVE);
+					IsDirective = true;
 				} else if (directiveOperand.InList(s)) {
 					sc.ChangeState(SCE_ASM_DIRECTIVEOPERAND);
 				} else if (extInstruction.InList(s)) {
 					sc.ChangeState(SCE_ASM_EXTINSTRUCTION);
 				}
 				sc.SetState(SCE_ASM_DEFAULT);
+				if (IsDirective && !strcmp(s, "comment")) {
+					char delimiter = options.delimiter.empty() ? '~' : options.delimiter.c_str()[0];
+					while (IsASpaceOrTab(sc.ch) && !sc.atLineEnd) {
+						sc.ForwardSetState(SCE_ASM_DEFAULT);
+					}
+					if (sc.ch == delimiter) {
+						sc.SetState(SCE_ASM_COMMENTDIRECTIVE);
+					}
+				}
 			}
-		}
-		else if (sc.state == SCE_ASM_COMMENT ) {
+		} else if (sc.state == SCE_ASM_COMMENTDIRECTIVE) {
+			char delimiter = options.delimiter.empty() ? '~' : options.delimiter.c_str()[0];
+			if (sc.ch == delimiter) {
+				while (!sc.atLineEnd) {
+					sc.Forward();
+				}
+				sc.SetState(SCE_ASM_DEFAULT);
+			}
+		} else if (sc.state == SCE_ASM_COMMENT ) {
 			if (sc.atLineEnd) {
 				sc.SetState(SCE_ASM_DEFAULT);
 			}
@@ -282,9 +365,101 @@ void SCI_METHOD LexerAsm::Lex(unsigned int startPos, int length, int initStyle,
 	sc.Complete();
 }
 
-void SCI_METHOD LexerAsm::Fold(unsigned int /* startPos */, int /* length */, int /* initStyle */, IDocument* /* pAccess */) {
+// Store both the current line's fold level and the next lines in the
+// level store to make it easy to pick up with each increment
+// and to make it possible to fiddle the current level for "else".
+
+void SCI_METHOD LexerAsm::Fold(unsigned int startPos, int length, int initStyle, IDocument *pAccess) {
 
-	return;
+	if (!options.fold)
+		return;
+
+	LexAccessor styler(pAccess);
+
+	unsigned int endPos = startPos + length;
+	int visibleChars = 0;
+	int lineCurrent = styler.GetLine(startPos);
+	int levelCurrent = SC_FOLDLEVELBASE;
+	if (lineCurrent > 0)
+		levelCurrent = styler.LevelAt(lineCurrent-1) >> 16;
+	int levelMinCurrent = levelCurrent;
+	int levelNext = levelCurrent;
+	char chNext = styler[startPos];
+	int styleNext = styler.StyleAt(startPos);
+	int style = initStyle;
+	char word[100];
+	int wordlen = 0;
+	const bool userDefinedFoldMarkers = !options.foldExplicitStart.empty() && !options.foldExplicitEnd.empty();
+	for (unsigned int i = startPos; i < endPos; i++) {
+		char ch = chNext;
+		chNext = styler.SafeGetCharAt(i + 1);
+		int stylePrev = style;
+		style = styleNext;
+		styleNext = styler.StyleAt(i + 1);
+		bool atEOL = (ch == '\r' && chNext != '\n') || (ch == '\n');
+		if (options.foldCommentMultiline && IsStreamCommentStyle(style)) {
+			if (!IsStreamCommentStyle(stylePrev)) {
+				levelNext++;
+			} else if (!IsStreamCommentStyle(styleNext) && !atEOL) {
+				// Comments don't end at end of line and the next character may be unstyled.
+				levelNext--;
+			}
+		}
+		if (options.foldCommentExplicit && ((style == SCE_ASM_COMMENT) || options.foldExplicitAnywhere)) {
+			if (userDefinedFoldMarkers) {
+				if (styler.Match(i, options.foldExplicitStart.c_str())) {
+ 					levelNext++;
+				} else if (styler.Match(i, options.foldExplicitEnd.c_str())) {
+ 					levelNext--;
+ 				}
+			} else {
+				if (ch == ';') {
+					if (chNext == '{') {
+						levelNext++;
+					} else if (chNext == '}') {
+						levelNext--;
+					}
+				}
+ 			}
+ 		}
+		if (options.foldSyntaxBased && (style == SCE_ASM_DIRECTIVE)) {
+			word[wordlen++] = static_cast<char>(LowerCase(ch));
+			if (wordlen == 100) {                   // prevent overflow  
+				word[0] = '\0';
+				wordlen = 1;
+			}
+			if (styleNext != SCE_ASM_DIRECTIVE) {   // reading directive ready
+				word[wordlen] = '\0';
+				wordlen = 0;
+				if (directives4foldstart.InList(word)) {
+					levelNext++;
+				} else if (directives4foldend.InList(word)){
+					levelNext--;
+				}    
+			}
+		}
+		if (!IsASpace(ch))
+			visibleChars++;
+		if (atEOL || (i == endPos-1)) {
+			int levelUse = levelCurrent;
+			int lev = levelUse | levelNext << 16;
+			if (visibleChars == 0 && options.foldCompact)
+				lev |= SC_FOLDLEVELWHITEFLAG;
+			if (levelUse < levelNext)
+				lev |= SC_FOLDLEVELHEADERFLAG;
+			if (lev != styler.LevelAt(lineCurrent)) {
+				styler.SetLevel(lineCurrent, lev);
+			}
+			lineCurrent++;
+			levelCurrent = levelNext;
+			levelMinCurrent = levelCurrent;
+			if (atEOL && (i == static_cast<unsigned int>(styler.Length()-1))) {
+				// There is an empty line at end of file so give it same level and empty
+				styler.SetLevel(lineCurrent, (levelCurrent | levelCurrent << 16) | SC_FOLDLEVELWHITEFLAG);
+			}
+			visibleChars = 0;
+		}
+	}
 }
 
 LexerModule lmAsm(SCLEX_ASM, LexerAsm::LexerFactoryAsm, "asm", asmWordListDesc);
diff --git a/lexers/LexBasic.cxx b/lexers/LexBasic.cxx
index 057afed65..55641edc1 100644
--- a/lexers/LexBasic.cxx
+++ b/lexers/LexBasic.cxx
@@ -1,7 +1,7 @@
 // Scintilla source code edit control
 /** @file LexBasic.cxx
  ** Lexer for BlitzBasic and PureBasic.
- ** Converted to lexer object by "Udo Lechner" <dlchnr(at)gmx(dot)net>
+ ** Converted to lexer object and added further folding features/properties by "Udo Lechner" <dlchnr(at)gmx(dot)net>
  **/
 // Copyright 1998-2003 by Neil Hodgson <neilh@scintilla.org>
 // The License.txt file describes the conditions under which this software may be distributed.
@@ -22,6 +22,7 @@
 #include <stdio.h>
 #include <stdarg.h>
 #include <assert.h>
+#include <ctype.h>
 
 #ifdef _MSC_VER
 #pragma warning(disable: 4786)
@@ -36,7 +37,6 @@
 
 #include "WordList.h"
 #include "LexAccessor.h"
-#include "Accessor.h"
 #include "StyleContext.h"
 #include "CharacterSet.h"
 #include "LexerModule.h"
@@ -147,9 +147,19 @@ static int CheckFreeFoldPoint(char const *token, int &level) {
 // Options used for LexerBasic
 struct OptionsBasic {
 	bool fold;
+	bool foldSyntaxBased;
+	bool foldCommentExplicit;
+	std::string foldExplicitStart;
+	std::string foldExplicitEnd;
+	bool foldExplicitAnywhere;
 	bool foldCompact;
 	OptionsBasic() {
 		fold = false;
+		foldSyntaxBased = true;
+		foldCommentExplicit = false;
+		foldExplicitStart = "";
+		foldExplicitEnd   = "";
+		foldExplicitAnywhere = false;
 		foldCompact = true;
 	}
 };
@@ -182,6 +192,23 @@ struct OptionSetBasic : public OptionSet<OptionsBasic> {
 	OptionSetBasic(const char * const wordListDescriptions[]) {
 		DefineProperty("fold", &OptionsBasic::fold);
 
+		DefineProperty("fold.basic.syntax.based", &OptionsBasic::foldSyntaxBased,
+			"Set this property to 0 to disable syntax based folding.");
+
+		DefineProperty("fold.basic.comment.explicit", &OptionsBasic::foldCommentExplicit,
+			"This option enables folding explicit fold points when using the Basic lexer. "
+			"Explicit fold points allows adding extra folding by placing a ;{ (BB/PB) or '{ (FB) comment at the start "
+			"and a ;} (BB/PB) or '} (FB) at the end of a section that should be folded.");
+
+		DefineProperty("fold.basic.explicit.start", &OptionsBasic::foldExplicitStart,
+			"The string to use for explicit fold start points, replacing the standard ;{ (BB/PB) or '{ (FB).");
+
+		DefineProperty("fold.basic.explicit.end", &OptionsBasic::foldExplicitEnd,
+			"The string to use for explicit fold end points, replacing the standard ;} (BB/PB) or '} (FB).");
+
+		DefineProperty("fold.basic.explicit.anywhere", &OptionsBasic::foldExplicitAnywhere,
+			"Set this property to 1 to enable explicit fold points anywhere, not just in line comments.");
+
 		DefineProperty("fold.compact", &OptionsBasic::foldCompact);
 
 		DefineWordListSets(wordListDescriptions);
@@ -235,7 +262,7 @@ public:
 		return new LexerBasic(';', CheckPureFoldPoint, purebasicWordListDesc);
 	}
 	static ILexer *LexerFactoryFreeBasic() {
-		return new LexerBasic('\'', CheckFreeFoldPoint, freebasicWordListDesc);
+		return new LexerBasic('\'', CheckFreeFoldPoint, freebasicWordListDesc );
 	}
 };
 
@@ -397,7 +424,6 @@ void SCI_METHOD LexerBasic::Fold(unsigned int startPos, int length, int /* initS
 	if (!options.fold)
 		return;
 
-
 	LexAccessor styler(pAccess);
 
 	int line = styler.GetLine(startPos);
@@ -406,12 +432,16 @@ void SCI_METHOD LexerBasic::Fold(unsigned int startPos, int length, int /* initS
 	int endPos = startPos + length;
 	char word[256];
 	int wordlen = 0;
+	const bool userDefinedFoldMarkers = !options.foldExplicitStart.empty() && !options.foldExplicitEnd.empty();
+	int cNext = styler[startPos];
 
 	// Scan for tokens at the start of the line (they may include
 	// whitespace, for tokens like "End Function"
 	for (int i = startPos; i < endPos; i++) {
-		int c = styler.SafeGetCharAt(i);
-		if (!done && !go) {
+		int c = cNext;
+		cNext = styler.SafeGetCharAt(i + 1);
+		bool atEOL = (c == '\r' && cNext != '\n') || (c == '\n');
+		if (options.foldSyntaxBased && !done && !go) {
 			if (wordlen) { // are we scanning a token already?
 				word[wordlen] = static_cast<char>(LowerCase(c));
 				if (!IsIdentifier(c)) { // done with token
@@ -441,7 +471,26 @@ void SCI_METHOD LexerBasic::Fold(unsigned int startPos, int length, int /* initS
 				}
 			}
 		}
-		if (c == '\n') { // line end
+		if (options.foldCommentExplicit && ((styler.StyleAt(i) == SCE_B_COMMENT) || options.foldExplicitAnywhere)) {
+			if (userDefinedFoldMarkers) {
+				if (styler.Match(i, options.foldExplicitStart.c_str())) {
+ 					level |= SC_FOLDLEVELHEADERFLAG;
+					go = 1;
+				} else if (styler.Match(i, options.foldExplicitEnd.c_str())) {
+ 					go = -1;
+ 				}
+			} else {
+				if (c == comment_char) {
+					if (cNext == '{') {
+						level |= SC_FOLDLEVELHEADERFLAG;
+						go = 1;
+					} else if (cNext == '}') {
+						go = -1;
+					}
+				}
+ 			}
+ 		}
+		if (atEOL) { // line end
 			if (!done && wordlen == 0 && options.foldCompact) // line was only space
 				level |= SC_FOLDLEVELWHITEFLAG;
 			if (level != styler.LevelAt(line))
diff --git a/lexers/LexD.cxx b/lexers/LexD.cxx
index 4b7d08daf..5b8f9e723 100644
--- a/lexers/LexD.cxx
+++ b/lexers/LexD.cxx
@@ -2,17 +2,17 @@
  ** Lexer for D.
  **
  ** Copyright (c) 2006 by Waldemar Augustyn <waldemar@wdmsys.com>
- ** Converted to lexer object by "Udo Lechner" <dlchnr(at)gmx(dot)net>
+ ** Converted to lexer object and added further folding features/properties by "Udo Lechner" <dlchnr(at)gmx(dot)net>
  **/
 // 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 <ctype.h>
 #include <stdio.h>
 #include <stdarg.h>
 #include <assert.h>
+#include <ctype.h>
 
 #ifdef _MSC_VER
 #pragma warning(disable: 4786)
@@ -27,7 +27,6 @@
 
 #include "WordList.h"
 #include "LexAccessor.h"
-#include "Accessor.h"
 #include "StyleContext.h"
 #include "CharacterSet.h"
 #include "LexerModule.h"
@@ -79,13 +78,25 @@ static bool IsStreamCommentStyle(int style) {
 // Options used for LexerD
 struct OptionsD {
 	bool fold;
+	bool foldSyntaxBased;
 	bool foldComment;
+	bool foldCommentMultiline;
+	bool foldCommentExplicit;
+	std::string foldExplicitStart;
+	std::string foldExplicitEnd;
+	bool foldExplicitAnywhere;
 	bool foldCompact;
 	int  foldAtElseInt;
 	bool foldAtElse;
 	OptionsD() {
 		fold = false;
+		foldSyntaxBased = true;
 		foldComment = false;
+		foldCommentMultiline = true;
+		foldCommentExplicit = true;
+		foldExplicitStart = "";
+		foldExplicitEnd   = "";
+		foldExplicitAnywhere = false;
 		foldCompact = true;
 		foldAtElseInt = -1;
 		foldAtElse = false;
@@ -107,8 +118,26 @@ struct OptionSetD : public OptionSet<OptionsD> {
 	OptionSetD() {
 		DefineProperty("fold", &OptionsD::fold);
 
+		DefineProperty("fold.d.syntax.based", &OptionsD::foldSyntaxBased,
+			"Set this property to 0 to disable syntax based folding.");
+
 		DefineProperty("fold.comment", &OptionsD::foldComment);
 
+		DefineProperty("fold.d.comment.multiline", &OptionsD::foldCommentMultiline,
+			"Set this property to 0 to disable folding multi-line comments when fold.comment=1.");
+
+		DefineProperty("fold.d.comment.explicit", &OptionsD::foldCommentExplicit,
+			"Set this property to 0 to disable folding explicit fold points when fold.comment=1.");
+
+		DefineProperty("fold.d.explicit.start", &OptionsD::foldExplicitStart,
+			"The string to use for explicit fold start points, replacing the standard //{.");
+
+		DefineProperty("fold.d.explicit.end", &OptionsD::foldExplicitEnd,
+			"The string to use for explicit fold end points, replacing the standard //}.");
+
+		DefineProperty("fold.d.explicit.anywhere", &OptionsD::foldExplicitAnywhere,
+			"Set this property to 1 to enable explicit fold points anywhere, not just in line comments.");
+
 		DefineProperty("fold.compact", &OptionsD::foldCompact);
 
 		DefineProperty("lexer.d.fold.at.else", &OptionsD::foldAtElseInt,
@@ -448,7 +477,6 @@ void SCI_METHOD LexerD::Lex(unsigned int startPos, int length, int initStyle, ID
 
 void SCI_METHOD LexerD::Fold(unsigned int startPos, int length, int initStyle, IDocument *pAccess) {
 
-
 	if (!options.fold)
 		return;
 
@@ -466,6 +494,7 @@ void SCI_METHOD LexerD::Fold(unsigned int startPos, int length, int initStyle, I
 	int styleNext = styler.StyleAt(startPos);
 	int style = initStyle;
 	bool foldAtElse = options.foldAtElseInt >= 0 ? options.foldAtElseInt != 0 : options.foldAtElse;
+	const bool userDefinedFoldMarkers = !options.foldExplicitStart.empty() && !options.foldExplicitEnd.empty();
 	for (unsigned int i = startPos; i < endPos; i++) {
 		char ch = chNext;
 		chNext = styler.SafeGetCharAt(i + 1);
@@ -473,7 +502,7 @@ void SCI_METHOD LexerD::Fold(unsigned int startPos, int length, int initStyle, I
 		style = styleNext;
 		styleNext = styler.StyleAt(i + 1);
 		bool atEOL = (ch == '\r' && chNext != '\n') || (ch == '\n');
-		if (options.foldComment && IsStreamCommentStyle(style)) {
+		if (options.foldComment && options.foldCommentMultiline && IsStreamCommentStyle(style)) {
 			if (!IsStreamCommentStyle(stylePrev)) {
 				levelNext++;
 			} else if (!IsStreamCommentStyle(styleNext) && !atEOL) {
@@ -481,7 +510,25 @@ void SCI_METHOD LexerD::Fold(unsigned int startPos, int length, int initStyle, I
 				levelNext--;
 			}
 		}
-		if (style == SCE_D_OPERATOR) {
+		if (options.foldComment && options.foldCommentExplicit && ((style == SCE_D_COMMENTLINE) || options.foldExplicitAnywhere)) {
+			if (userDefinedFoldMarkers) {
+				if (styler.Match(i, options.foldExplicitStart.c_str())) {
+ 					levelNext++;
+				} else if (styler.Match(i, options.foldExplicitEnd.c_str())) {
+ 					levelNext--;
+ 				}
+			} else {
+				if ((ch == '/') && (chNext == '/')) {
+					char chNext2 = styler.SafeGetCharAt(i + 2);
+					if (chNext2 == '{') {
+						levelNext++;
+					} else if (chNext2 == '}') {
+						levelNext--;
+					}
+				}
+ 			}
+ 		}
+		if (options.foldSyntaxBased && (style == SCE_D_OPERATOR)) {
 			if (ch == '{') {
 				// Measure the minimum before a '{' to allow
 				// folding on "} else {"
@@ -494,14 +541,14 @@ void SCI_METHOD LexerD::Fold(unsigned int startPos, int length, int initStyle, I
 			}
 		}
 		if (atEOL || (i == endPos-1)) {
-			if (options.foldComment) {  // Handle nested comments
+			if (options.foldComment && options.foldCommentMultiline) {  // Handle nested comments
 				int nc;
 				nc =  styler.GetLineState(lineCurrent);
 				nc -= lineCurrent>0? styler.GetLineState(lineCurrent-1): 0;
 				levelNext += nc;
 			}
 			int levelUse = levelCurrent;
-			if (foldAtElse) {
+			if (options.foldSyntaxBased && foldAtElse) {
 				levelUse = levelMinCurrent;
 			}
 			int lev = levelUse | levelNext << 16;