1 files changed, 74 insertions, 0 deletions
diff --git a/src/mongo/gotools/common/json/single_quoted.go b/src/mongo/gotools/common/json/single_quoted.go
new file mode 100644
index 00000000000..ca465ee04f2
--- /dev/null
+++ b/src/mongo/gotools/common/json/single_quoted.go
@@ -0,0 +1,74 @@
+package json
+
+// Transition functions for recognizing single-quoted strings.
+// Adapted from encoding/json/scanner.go.
+
+// stateInSingleQuotedString is the state after reading `'`.
+func stateInSingleQuotedString(s *scanner, c int) int {
+	if c == '\'' {
+		s.step = stateEndValue
+		return scanContinue
+	}
+	if c == '\\' {
+		s.step = stateInSingleQuotedStringEsc
+		return scanContinue
+	}
+	if c < 0x20 {
+		return s.error(c, "in string literal")
+	}
+	return scanContinue
+}
+
+// stateInSingleQuotedStringEsc is the state after reading `'\` during a quoted string.
+func stateInSingleQuotedStringEsc(s *scanner, c int) int {
+	switch c {
+	case 'b', 'f', 'n', 'r', 't', '\\', '/', '\'':
+		s.step = stateInSingleQuotedString
+		return scanContinue
+	}
+	if c == 'u' {
+		s.step = stateInSingleQuotedStringEscU
+		return scanContinue
+	}
+	return s.error(c, "in string escape code")
+}
+
+// stateInSingleQuotedStringEscU is the state after reading `'\u` during a quoted string.
+func stateInSingleQuotedStringEscU(s *scanner, c int) int {
+	if '0' <= c && c <= '9' || 'a' <= c && c <= 'f' || 'A' <= c && c <= 'F' {
+		s.step = stateInSingleQuotedStringEscU1
+		return scanContinue
+	}
+	// numbers
+	return s.error(c, "in \\u hexadecimal character escape")
+}
+
+// stateInSingleQuotedStringEscU1 is the state after reading `'\u1` during a quoted string.
+func stateInSingleQuotedStringEscU1(s *scanner, c int) int {
+	if '0' <= c && c <= '9' || 'a' <= c && c <= 'f' || 'A' <= c && c <= 'F' {
+		s.step = stateInSingleQuotedStringEscU12
+		return scanContinue
+	}
+	// numbers
+	return s.error(c, "in \\u hexadecimal character escape")
+}
+
+// stateInSingleQuotedStringEscU12 is the state after reading `'\u12` during a quoted string.
+func stateInSingleQuotedStringEscU12(s *scanner, c int) int {
+	if '0' <= c && c <= '9' || 'a' <= c && c <= 'f' || 'A' <= c && c <= 'F' {
+		s.step = stateInSingleQuotedStringEscU123
+		return scanContinue
+	}
+	// numbers
+	return s.error(c, "in \\u hexadecimal character escape")
+}
+
+// stateInSingleQuotedStringEscU123 is the state after reading `'\u123` during a quoted string.
+func stateInSingleQuotedStringEscU123(s *scanner, c int) int {
+	if '0' <= c && c <= '9' || 'a' <= c && c <= 'f' || 'A' <= c && c <= 'F' {
+		s.step = stateInSingleQuotedString
+		return scanContinue
+	}
+	// numbers
+	return s.error(c, "in \\u hexadecimal character escape")
+}