[Bash] Highlight ++, -- ( in arithmetic expression) and += as operator

[zufuliu]

test case:

hello="hello, "
hello+=word
echo $hello

for ((i = 2; i > 0; i--)); do
   echo postfix dec $i
done
for ((i = 2; i > 0; --i)); do
   echo prefix dec $i
done
for ((i = 0; i < 2; i++)); do
   echo postfix inc $i
done
for ((i = 0; i < 2; ++i)); do
   echo prefix inc $i
done

[nyamatongwe]

This change uses SCE_SH_OPERATOR for ++ and -- in arithmetic expressions but does not improve += outside arithmetic expressions.

@@ -996,7 +996,7 @@ void SCI_METHOD LexerBash::Lex(Sci_PositionU startPos, Sci_Position length, int
 					}
 				}
 			} else if (setWordStart.Contains(sc.ch)) {
-				sc.SetState(SCE_SH_WORD | insideCommand);
+				sc.SetState(((cmdState == CmdState::Arithmetic) ? SCE_SH_IDENTIFIER : SCE_SH_WORD) | insideCommand);
 			} else if (sc.ch == '#') {
 				if (stylePrev != SCE_SH_WORD && stylePrev != SCE_SH_IDENTIFIER &&
 					(sc.currentPos == 0 || setMetaCharacter.Contains(sc.chPrev))) {
@@ -1045,7 +1045,11 @@ void SCI_METHOD LexerBash::Lex(Sci_PositionU startPos, Sci_Position length, int
 			} else if (sc.ch == '-' && // test operator or short and long option
 					   (IsUpperOrLowerCase(sc.chNext) || sc.chNext == '-') &&
 					   IsASpace(sc.chPrev)) {
-				sc.SetState(SCE_SH_WORD | insideCommand);
+				if (cmdState == CmdState::Arithmetic && sc.ch == '-') {
+					sc.SetState(SCE_SH_OPERATOR | insideCommand);
+				} else {
+					sc.SetState(SCE_SH_WORD | insideCommand);
+				}
 				sc.Forward();
 			} else if (setBashOperator.Contains(sc.ch)) {
 				bool isCmdDelim = false;

[zufuliu]

Try following patch?
bash-operator.patch

diff --git a/lexers/LexBash.cxx b/lexers/LexBash.cxx
index d9506690..aab2d7a7 100644
--- a/lexers/LexBash.cxx
+++ b/lexers/LexBash.cxx
@@ -647,7 +647,7 @@ void SCI_METHOD LexerBash::Lex(Sci_PositionU startPos, Sci_Position length, int
 				break;
 			case SCE_SH_WORD:
 				// "." never used in Bash variable names but used in file names
-				if (!setWord.Contains(sc.ch)) {
+				if (!setWord.Contains(sc.ch) || sc.Match('+', '=')) {
 					char s[500];
 					sc.GetCurrent(s, sizeof(s));
 					int identifierStyle = SCE_SH_IDENTIFIER | insideCommand;
@@ -996,7 +996,7 @@ void SCI_METHOD LexerBash::Lex(Sci_PositionU startPos, Sci_Position length, int
 					}
 				}
 			} else if (setWordStart.Contains(sc.ch)) {
-				sc.SetState(SCE_SH_WORD | insideCommand);
+				sc.SetState(((cmdState == CmdState::Arithmetic)? SCE_SH_IDENTIFIER : SCE_SH_WORD) | insideCommand);
 			} else if (sc.ch == '#') {
 				if (stylePrev != SCE_SH_WORD && stylePrev != SCE_SH_IDENTIFIER &&
 					(sc.currentPos == 0 || setMetaCharacter.Contains(sc.chPrev))) {
@@ -1043,6 +1043,7 @@ void SCI_METHOD LexerBash::Lex(Sci_PositionU startPos, Sci_Position length, int
 					HereDoc.Indent = false;
 				}
 			} else if (sc.ch == '-' && // test operator or short and long option
+					   cmdState != CmdState::Arithmetic &&
 					   (IsUpperOrLowerCase(sc.chNext) || sc.chNext == '-') &&
 					   IsASpace(sc.chPrev)) {
 				sc.SetState(SCE_SH_WORD | insideCommand);

[zufuliu]

Similar to issue #203, arithmetic expression can span multilines without line continuation.

echo $((2
- 1))
echo $[2
- 1]
for ((i = 0; i < 2;
	i++)); do
	echo postfix inc $i
done
for ((i = 1; i < 4;
	i<<=1)); do
	echo postfix inc $i
done

bash-operator-0906.patch

diff --git a/lexers/LexBash.cxx b/lexers/LexBash.cxx
index 647cc262..47e4a54a 100644
--- a/lexers/LexBash.cxx
+++ b/lexers/LexBash.cxx
@@ -662,7 +662,7 @@ void SCI_METHOD LexerBash::Lex(Sci_PositionU startPos, Sci_Position length, int
 		// handle line continuation, updates per-line stored state
 		if (sc.atLineStart) {
 			CmdState state = CmdState::Body;	// force backtrack while retaining cmdState
-			if (!StyleForceBacktrack(MaskCommand(sc.state))) {
+			if (!StyleForceBacktrack(MaskCommand(sc.state)) && !AnyOf(cmdState, CmdState::Arithmetic)) {
 				if (!QuoteStack.lineContinuation) {	// retain last line's state
 					cmdState = CmdState::Start;
 				}