diff --git a/querylexer.go b/querylexer.go
index 61153cb..960681d 100644
--- a/querylexer.go
+++ b/querylexer.go
@@ -272,6 +272,23 @@
 				return l.errorf("invalid unicode escape: \\u" + code)
 			}
 			growingString += string(rune(intcode))
+		} else if l.follow("\\U") {
+			l.pos += 2
+			code := ""
+			for i := 0; i < 8; i++ {
+				c := l.peek()
+				l.pos++
+				if !isHexDigit(c) {
+					return l.errorf("unfinished unicode escape")
+				}
+				code = code + string(c)
+			}
+			l.pos--
+			intcode, err := strconv.ParseInt(code, 16, 32)
+			if err != nil {
+				return l.errorf("invalid unicode escape: \\u" + code)
+			}
+			growingString += string(rune(intcode))
 		} else if l.follow("\\") {
 			l.pos++
 			return l.errorf("invalid escape sequence: \\" + string(l.peek()))
diff --git a/querylexer_test.go b/querylexer_test.go
index a9bd674..48338e5 100644
--- a/querylexer_test.go
+++ b/querylexer_test.go
@@ -10,11 +10,13 @@
 		token := <-ch
 		if token != expected {
 			t.Log("While testing #", idx, ":", input)
+			t.Log("compared (got)", token, "to (expected)", expected)
+			t.Log("\tvalue:", token.val, "<->", expected.val)
+			t.Log("\tvalue as bytes:", []byte(token.val), "<->", []byte(expected.val))
+			t.Log("\ttype:", token.typ.String(), "<->", expected.typ.String())
+			t.Log("\tline:", token.Line, "<->", expected.Line)
+			t.Log("\tcolumn:", token.Col, "<->", expected.Col)
 			t.Log("compared", token, "to", expected)
-			t.Log(token.val, "<->", expected.val)
-			t.Log(token.typ, "<->", expected.typ)
-			t.Log(token.Line, "<->", expected.Line)
-			t.Log(token.Col, "<->", expected.Col)
 			t.FailNow()
 		}
 	}
@@ -48,9 +50,9 @@
 }
 
 func TestLexString(t *testing.T) {
-	testQLFlow(t, "'foo'", []token{
-		token{Position{1, 2}, tokenString, "foo"},
-		token{Position{1, 6}, tokenEOF, ""},
+	testQLFlow(t, "'foo\n'", []token{
+		token{Position{1, 2}, tokenString, "foo\n"},
+		token{Position{2, 2}, tokenEOF, ""},
 	})
 }
 
@@ -61,6 +63,37 @@
 	})
 }
 
+func TestLexStringEscapes(t *testing.T) {
+	testQLFlow(t, `"foo \" \' \b \f \/ \t \r \\ \u03A9 \U00012345 \n bar"`, []token{
+		token{Position{1, 2}, tokenString, "foo \" ' \b \f / \t \r \\ \u03A9 \U00012345 \n bar"},
+		token{Position{1, 55}, tokenEOF, ""},
+	})
+}
+
+func TestLexStringUnfinishedUnicode4(t *testing.T) {
+	testQLFlow(t, `"\u000"`, []token{
+		token{Position{1, 2}, tokenError, "unfinished unicode escape"},
+	})
+}
+
+func TestLexStringUnfinishedUnicode8(t *testing.T) {
+	testQLFlow(t, `"\U0000"`, []token{
+		token{Position{1, 2}, tokenError, "unfinished unicode escape"},
+	})
+}
+
+func TestLexStringInvalidEscape(t *testing.T) {
+	testQLFlow(t, `"\x"`, []token{
+		token{Position{1, 2}, tokenError, "invalid escape sequence: \\x"},
+	})
+}
+
+func TestLexStringUnfinished(t *testing.T) {
+	testQLFlow(t, `"bar`, []token{
+		token{Position{1, 2}, tokenError, "unclosed string"},
+	})
+}
+
 func TestLexKey(t *testing.T) {
 	testQLFlow(t, "foo", []token{
 		token{Position{1, 1}, tokenKey, "foo"},
@@ -95,3 +128,51 @@
 		token{Position{1, 12}, tokenEOF, ""},
 	})
 }
+
+func TestLexInteger(t *testing.T) {
+	testQLFlow(t, "100 +200 -300", []token{
+		token{Position{1, 1}, tokenInteger, "100"},
+		token{Position{1, 5}, tokenInteger, "+200"},
+		token{Position{1, 10}, tokenInteger, "-300"},
+		token{Position{1, 14}, tokenEOF, ""},
+	})
+}
+
+func TestLexFloat(t *testing.T) {
+	testQLFlow(t, "100.0 +200.0 -300.0", []token{
+		token{Position{1, 1}, tokenFloat, "100.0"},
+		token{Position{1, 7}, tokenFloat, "+200.0"},
+		token{Position{1, 14}, tokenFloat, "-300.0"},
+		token{Position{1, 20}, tokenEOF, ""},
+	})
+}
+
+func TestLexFloatWithMultipleDots(t *testing.T) {
+	testQLFlow(t, "4.2.", []token{
+		token{Position{1, 1}, tokenError, "cannot have two dots in one float"},
+	})
+}
+
+func TestLexFloatLeadingDot(t *testing.T) {
+	testQLFlow(t, "+.1", []token{
+		token{Position{1, 1}, tokenError, "cannot start float with a dot"},
+	})
+}
+
+func TestLexFloatWithTrailingDot(t *testing.T) {
+	testQLFlow(t, "42.", []token{
+		token{Position{1, 1}, tokenError, "float cannot end with a dot"},
+	})
+}
+
+func TestLexNumberWithoutDigit(t *testing.T) {
+	testQLFlow(t, "+", []token{
+		token{Position{1, 1}, tokenError, "no digit in that number"},
+	})
+}
+
+func TestLexUnknown(t *testing.T) {
+	testQLFlow(t, "^", []token{
+		token{Position{1, 1}, tokenError, "unexpected char: '94'"},
+	})
+}