Fixes #31 : Use RFC 3339 for datetimes

lexer.go

diff --git a/lexer.go b/lexer.go
index 41b8af7..7835116 100644
--- a/lexer.go
+++ b/lexer.go
@@ -192,7 +192,10 @@
 			return l.lexKey
 		}
 
-		if dateRegexp.FindString(l.input[l.pos:]) != "" {
+		dateMatch := dateRegexp.FindString(l.input[l.pos:])
+		if dateMatch != "" {
+			l.ignore()
+			l.pos += len(dateMatch)
 			return l.lexDate
 		}
 
@@ -214,8 +217,6 @@
 }
 
 func (l *tomlLexer) lexDate() tomlLexStateFn {
-	l.ignore()
-	l.pos += 20 // Fixed size of a date in TOML
 	l.emit(tokenDate)
 	return l.lexRvalue
 }
@@ -461,7 +462,7 @@
 }
 
 func init() {
-	dateRegexp = regexp.MustCompile("^\\d{1,4}-\\d{2}-\\d{2}T\\d{2}:\\d{2}:\\d{2}Z")
+	dateRegexp = regexp.MustCompile("^\\d{1,4}-\\d{2}-\\d{2}T\\d{2}:\\d{2}:\\d{2}(\\.\\d{1,9})?(Z|[+-]\\d{2}:\\d{2})")
 }
 
 // Entry point

lexer_test.go

diff --git a/lexer_test.go b/lexer_test.go
index 176abf8..cc8fb47 100644
--- a/lexer_test.go
+++ b/lexer_test.go
@@ -273,7 +273,13 @@
 
 func TestDateRegexp(t *testing.T) {
 	if dateRegexp.FindString("1979-05-27T07:32:00Z") == "" {
-		t.Fail()
+		t.Error("basic lexing")
+	}
+	if dateRegexp.FindString("1979-05-27T00:32:00-07:00") == "" {
+		t.Error("offset lexing")
+	}
+	if dateRegexp.FindString("1979-05-27T00:32:00.999999-07:00") == "" {
+		t.Error("nano precision lexing")
 	}
 }
 
@@ -284,6 +290,18 @@
 		token{Position{1, 7}, tokenDate, "1979-05-27T07:32:00Z"},
 		token{Position{1, 27}, tokenEOF, ""},
 	})
+	testFlow(t, "foo = 1979-05-27T00:32:00-07:00", []token{
+		token{Position{1, 1}, tokenKey, "foo"},
+		token{Position{1, 5}, tokenEqual, "="},
+		token{Position{1, 7}, tokenDate, "1979-05-27T00:32:00-07:00"},
+		token{Position{1, 32}, tokenEOF, ""},
+	})
+	testFlow(t, "foo = 1979-05-27T00:32:00.999999-07:00", []token{
+		token{Position{1, 1}, tokenKey, "foo"},
+		token{Position{1, 5}, tokenEqual, "="},
+		token{Position{1, 7}, tokenDate, "1979-05-27T00:32:00.999999-07:00"},
+		token{Position{1, 39}, tokenEOF, ""},
+	})
 }
 
 func TestFloatEndingWithDot(t *testing.T) {

parser.go

diff --git a/parser.go b/parser.go
index 60918cc..e83647d 100644
--- a/parser.go
+++ b/parser.go
@@ -222,7 +222,7 @@
 		}
 		return val
 	case tokenDate:
-		val, err := time.Parse(time.RFC3339, tok.val)
+		val, err := time.Parse(time.RFC3339Nano, tok.val)
 		if err != nil {
 			p.raiseError(tok, "%s", err)
 		}

parser_test.go

diff --git a/parser_test.go b/parser_test.go
index 136c795..afaabd3 100644
--- a/parser_test.go
+++ b/parser_test.go
@@ -88,6 +88,21 @@
 	})
 }
 
+func TestDateOffset(t *testing.T) {
+	tree, err := Load("a = 1979-05-27T00:32:00-07:00")
+	assertTree(t, tree, err, map[string]interface{}{
+		"a": time.Date(1979, time.May, 27, 0, 32, 0, 0, time.FixedZone("", -7 * 60 * 60)),
+	})
+}
+
+func TestDateNano(t *testing.T) {
+	tree, err := Load("a = 1979-05-27T00:32:00.999999999-07:00")
+	assertTree(t, tree, err, map[string]interface{}{
+		"a": time.Date(1979, time.May, 27, 0, 32, 0, 999999999, time.FixedZone("", -7 * 60 * 60)),
+	})
+}
+
+
 func TestSimpleString(t *testing.T) {
 	tree, err := Load("a = \"hello world\"")
 	assertTree(t, tree, err, map[string]interface{}{