Allow key values to be quoted

conf/lex.go

@@ -248,7 +248,7 @@ func lexTopValueEnd(lx *lexer) stateFn {
 }
 
 // lexKeyStart consumes a key name up until the first non-whitespace character.
-// lexKeyStart will ignore whitespace.
+// lexKeyStart will ignore whitespace. It will also eat enclosing quotes.
 func lexKeyStart(lx *lexer) stateFn {
 	r := lx.peek()
 	switch {
@@ -257,12 +257,27 @@ func lexKeyStart(lx *lexer) stateFn {
 	case isWhitespace(r) || isNL(r):
 		lx.next()
 		return lexSkip(lx, lexKeyStart)
+	case r == sqStringStart || r == dqStringStart:
+		lx.next()
+		return lexSkip(lx, lexQuotedKey)
 	}
 	lx.ignore()
 	lx.next()
 	return lexKey
 }
 
+// lexQuotedKey consumes the text of a key between quotes.
+func lexQuotedKey(lx *lexer) stateFn {
+	r := lx.peek()
+	if r == sqStringEnd || r == dqStringEnd {
+		lx.emit(itemKey)
+		lx.next()
+		return lexSkip(lx, lexKeyEnd)
+	}
+	lx.next()
+	return lexQuotedKey
+}
+
 // lexKey consumes the text of a key. Assumes that the first character (which
 // is not whitespace) has already been consumed.
 func lexKey(lx *lexer) stateFn {

conf/lex_test.go

@@ -246,6 +246,32 @@ func TestNestedMaps(t *testing.T) {
 	expect(t, lx, expectedItems)
 }
 
+func TestQuotedKeys(t *testing.T) {
+	expectedItems := []item{
+		{itemKey, "foo", 1},
+		{itemInteger, "123", 1},
+		{itemEOF, "", 1},
+	}
+	lx := lex("foo : 123")
+	expect(t, lx, expectedItems)
+	lx = lex("'foo' : 123")
+	expect(t, lx, expectedItems)
+	lx = lex("\"foo\" : 123")
+	expect(t, lx, expectedItems)
+}
+
+func TestQuotedKeysWithSpace(t *testing.T) {
+	expectedItems := []item{
+		{itemKey, " foo", 1},
+		{itemInteger, "123", 1},
+		{itemEOF, "", 1},
+	}
+	lx := lex("' foo' : 123")
+	expect(t, lx, expectedItems)
+	lx = lex("\" foo\" : 123")
+	expect(t, lx, expectedItems)
+}
+
 func TestColonKeySep(t *testing.T) {
 	expectedItems := []item{
 		{itemKey, "foo", 1},