From 3b00596b2e9ee541bbd72dc50cc0c60e2b46c69c Mon Sep 17 00:00:00 2001
From: Cameron Moore <moorereason@gmail.com>
Date: Mon, 13 Mar 2017 22:04:08 -0500
Subject: [PATCH] Support lowercase unicode escape sequences (#140)

---
 lexer_test.go | 24 ++++++++++++++++++++++++
 token.go      |  3 ++-
 2 files changed, 26 insertions(+), 1 deletion(-)

diff --git a/lexer_test.go b/lexer_test.go
index 676cdb0..6b324ea 100644
--- a/lexer_test.go
+++ b/lexer_test.go
@@ -531,6 +531,30 @@ func TestKeyEqualStringUnicodeEscape(t *testing.T) {
 		{Position{1, 8}, tokenString, "hello δ"},
 		{Position{1, 25}, tokenEOF, ""},
 	})
+	testFlow(t, `foo = "\uabcd"`, []token{
+		{Position{1, 1}, tokenKey, "foo"},
+		{Position{1, 5}, tokenEqual, "="},
+		{Position{1, 8}, tokenString, "\uabcd"},
+		{Position{1, 15}, tokenEOF, ""},
+	})
+	testFlow(t, `foo = "\uABCD"`, []token{
+		{Position{1, 1}, tokenKey, "foo"},
+		{Position{1, 5}, tokenEqual, "="},
+		{Position{1, 8}, tokenString, "\uABCD"},
+		{Position{1, 15}, tokenEOF, ""},
+	})
+	testFlow(t, `foo = "\U000bcdef"`, []token{
+		{Position{1, 1}, tokenKey, "foo"},
+		{Position{1, 5}, tokenEqual, "="},
+		{Position{1, 8}, tokenString, "\U000bcdef"},
+		{Position{1, 19}, tokenEOF, ""},
+	})
+	testFlow(t, `foo = "\U000BCDEF"`, []token{
+		{Position{1, 1}, tokenKey, "foo"},
+		{Position{1, 5}, tokenEqual, "="},
+		{Position{1, 8}, tokenString, "\U000BCDEF"},
+		{Position{1, 19}, tokenEOF, ""},
+	})
 	testFlow(t, `foo = "\u2"`, []token{
 		{Position{1, 1}, tokenKey, "foo"},
 		{Position{1, 5}, tokenEqual, "="},
diff --git a/token.go b/token.go
index e598cf9..5581fe0 100644
--- a/token.go
+++ b/token.go
@@ -135,5 +135,6 @@ func isDigit(r rune) bool {
 
 func isHexDigit(r rune) bool {
 	return isDigit(r) ||
-		r == 'A' || r == 'B' || r == 'C' || r == 'D' || r == 'E' || r == 'F'
+		(r >= 'a' && r <= 'f') ||
+		(r >= 'A' && r <= 'F')
 }