Fix str split with whitespace (#182)

Author: S-YOU

runtime/str.go

@@ -590,7 +590,12 @@ func strSplit(f *Frame, args Args, kwargs KWArgs) (*Object, *BaseException) {
 	s := toStrUnsafe(args[0]).Value()
 	var parts []string
 	if sep == "" {
+		s = strings.TrimLeft(s, string(strASCIISpaces))
 		parts = whitespaceSplitRegexp.Split(s, maxSplit)
+		l := len(parts)
+		if l > 0 && strings.Trim(parts[l-1], string(strASCIISpaces)) == "" {
+			parts = parts[:l-1]
+		}
 	} else {
 		parts = strings.SplitN(s, sep, maxSplit)
 	}

runtime/str_test.go

@@ -358,6 +358,16 @@ func TestStrMethods(t *testing.T) {
 		{"split", wrapArgs("a \tb\nc", None, 1), newTestList("a", "b\nc").ToObject(), nil},
 		{"split", wrapArgs("foo", 1), nil, mustCreateException(TypeErrorType, "expected a str separator")},
 		{"split", wrapArgs("foo", ""), nil, mustCreateException(ValueErrorType, "empty separator")},
+		{"split", wrapArgs(""), newTestList().ToObject(), nil},
+		{"split", wrapArgs(" "), newTestList().ToObject(), nil},
+		{"split", wrapArgs("", "x"), newTestList("").ToObject(), nil},
+		{"split", wrapArgs(" ", " ", 1), newTestList("", "").ToObject(), nil},
+		{"split", wrapArgs("aa", "a", 2), newTestList("", "", "").ToObject(), nil},
+		{"split", wrapArgs(" a ", "a"), newTestList(" ", " ").ToObject(), nil},
+		{"split", wrapArgs("a b c d", None, 1), newTestList("a", "b c d").ToObject(), nil},
+		{"split", wrapArgs("a b c d "), newTestList("a", "b", "c", "d").ToObject(), nil},
+		{"split", wrapArgs(" a b c d ", None, 1), newTestList("a", "b c d ").ToObject(), nil},
+		{"split", wrapArgs("   a b c d ", None, 0), newTestList("a b c d ").ToObject(), nil},
 		{"splitlines", wrapArgs(""), NewList().ToObject(), nil},
 		{"splitlines", wrapArgs("\n"), newTestList("").ToObject(), nil},
 		{"splitlines", wrapArgs("foo"), newTestList("foo").ToObject(), nil},

testing/str_test.py

@@ -243,6 +243,19 @@ def __index__(self):
 except TypeError:
   pass
 
+# Test split
+assert "".split() == []
+assert " ".split() == []
+assert "".split('x') == ['']
+assert "a".split() == ['a']
+assert " ".split(" ", 1) == ['', '']
+assert "aa".split("a", 2) == ['', '', '']
+assert " a ".split() == ['a']
+assert 'a b c d'.split(None, 1) == ['a', 'b c d']
+assert 'a b c d '.split() == ['a', 'b', 'c', 'd']
+assert ' a b c d '.split(None, 1) == ['a', 'b c d ']
+assert '   a b c d'.split(None, 0) == ['a b c d']
+
 # Test zfill
 assert '123'.zfill(2) == '123'
 assert '123'.zfill(3) == '123'