Hide implementation of EscapeSequence and use const. Add tests for escape

sequences.

3 files changed, 26 insertions, 13 deletions

diff --git a/lexers/LexCPP.cxx b/lexers/LexCPP.cxx
index af60dce3a..09e5b1cb4 100644
--- a/lexers/LexCPP.cxx
+++ b/lexers/LexCPP.cxx
@@ -163,18 +163,14 @@ void highlightTaskMarker(StyleContext &sc, LexAccessor &styler,
 	}
 }
 
-struct EscapeSequence {
-	int digitsLeft;
-	CharacterSet setHexDigits;
-	CharacterSet setOctDigits;
-	CharacterSet setNoneNumeric;
-	CharacterSet *escapeSetValid;
-	EscapeSequence() {
-		digitsLeft = 0;
-		escapeSetValid = nullptr;
-		setHexDigits = CharacterSet(CharacterSet::setDigits, "ABCDEFabcdef");
-		setOctDigits = CharacterSet(CharacterSet::setNone, "01234567");
-	}
+class EscapeSequence {
+	const CharacterSet setHexDigits = CharacterSet(CharacterSet::setDigits, "ABCDEFabcdef");
+	const CharacterSet setOctDigits = CharacterSet(CharacterSet::setNone, "01234567");
+	const CharacterSet setNoneNumeric;
+	const CharacterSet *escapeSetValid = nullptr;
+	int digitsLeft = 0;
+public:
+	EscapeSequence() = default;
 	void resetEscapeState(int nextChar) {
 		digitsLeft = 0;
 		escapeSetValid = &setNoneNumeric;
@@ -195,6 +191,9 @@ struct EscapeSequence {
 	bool atEscapeEnd(int currChar) const {
 		return (digitsLeft <= 0) || !escapeSetValid->Contains(currChar);
 	}
+	void consumeDigit() noexcept {
+		digitsLeft--;
+	}
 };
 
 std::string GetRestOfLine(LexAccessor &styler, Sci_Position start, bool allowSpace) {
@@ -1107,7 +1106,7 @@ void SCI_METHOD LexerCPP::Lex(Sci_PositionU startPos, Sci_Position length, int i
 				}
 				break;
 			case SCE_C_ESCAPESEQUENCE:
-				escapeSeq.digitsLeft--;
+				escapeSeq.consumeDigit();
 				if (!escapeSeq.atEscapeEnd(sc.ch)) {
 					break;
 				}
diff --git a/lexilla/test/examples/cpp/x.cxx b/lexilla/test/examples/cpp/x.cxx
index 8e42167b2..c1f052882 100644
--- a/lexilla/test/examples/cpp/x.cxx
+++ b/lexilla/test/examples/cpp/x.cxx
@@ -17,4 +17,11 @@ int main() {
 	// JavaScript regular expression (14) tests
 	let a = /a/;
 	let b = /[a-z]+/gi;
+
+	// Escape sequence (27) tests
+	printf("\'\"\?\\\a\b\f\n\r\t\v \P");
+	printf("\0a \013a \019");
+	printf("\x013ac \xdz");
+	printf("\ua34df \uz");
+	printf("\Ua34df7833 \Uz");
 }
diff --git a/lexilla/test/examples/cpp/x.cxx.styled b/lexilla/test/examples/cpp/x.cxx.styled
index c269ed1b4..e4241eba2 100644
--- a/lexilla/test/examples/cpp/x.cxx.styled
+++ b/lexilla/test/examples/cpp/x.cxx.styled
@@ -17,4 +17,11 @@
 	{2}// JavaScript regular expression (14) tests
 {0}	{5}let{0} {11}a{0} {10}={0} {14}/a/{10};{0}
 	{5}let{0} {11}b{0} {10}={0} {14}/[a-z]+/gi{10};{0}
+
+	{2}// Escape sequence (27) tests
+{0}	{11}printf{10}({6}"{27}\'\"\?\\\a\b\f\n\r\t\v{6} {27}\P{6}"{10});{0}
+	{11}printf{10}({6}"{27}\0{6}a {27}\013{6}a {27}\01{6}9"{10});{0}
+	{11}printf{10}({6}"{27}\x013a{6}c {27}\xd{6}z"{10});{0}
+	{11}printf{10}({6}"{27}\ua34d{6}f {27}\u{6}z"{10});{0}
+	{11}printf{10}({6}"{27}\Ua34df783{6}3 {27}\U{6}z"{10});{0}
 {10}}{0}