[Runtime] Implement str.isalpha(), str.isdigit(), str.isalnum() (#239)

runtime/str.go

@@ -335,6 +335,54 @@ func strHash(f *Frame, o *Object) (*Object, *BaseException) {
 	return h.ToObject(), nil
 }
 
+func strIsAlNum(f *Frame, args Args, kwargs KWArgs) (*Object, *BaseException) {
+	if raised := checkMethodArgs(f, "isalnum", args, StrType); raised != nil {
+		return nil, raised
+	}
+	s := toStrUnsafe(args[0]).Value()
+	if len(s) == 0 {
+		return False.ToObject(), nil
+	}
+	for i := range s {
+		if !isAlNum(s[i]) {
+			return False.ToObject(), nil
+		}
+	}
+	return True.ToObject(), nil
+}
+
+func strIsAlpha(f *Frame, args Args, kwargs KWArgs) (*Object, *BaseException) {
+	if raised := checkMethodArgs(f, "isalpha", args, StrType); raised != nil {
+		return nil, raised
+	}
+	s := toStrUnsafe(args[0]).Value()
+	if len(s) == 0 {
+		return False.ToObject(), nil
+	}
+	for i := range s {
+		if !isAlpha(s[i]) {
+			return False.ToObject(), nil
+		}
+	}
+	return True.ToObject(), nil
+}
+
+func strIsDigit(f *Frame, args Args, kwargs KWArgs) (*Object, *BaseException) {
+	if raised := checkMethodArgs(f, "isdigit", args, StrType); raised != nil {
+		return nil, raised
+	}
+	s := toStrUnsafe(args[0]).Value()
+	if len(s) == 0 {
+		return False.ToObject(), nil
+	}
+	for i := range s {
+		if !isDigit(s[i]) {
+			return False.ToObject(), nil
+		}
+	}
+	return True.ToObject(), nil
+}
+
 func strJoin(f *Frame, args Args, _ KWArgs) (*Object, *BaseException) {
 	if raised := checkMethodArgs(f, "join", args, StrType, ObjectType); raised != nil {
 		return nil, raised
@@ -777,6 +825,9 @@ func initStrType(dict map[string]*Object) {
 	dict["decode"] = newBuiltinFunction("decode", strDecode).ToObject()
 	dict["endswith"] = newBuiltinFunction("endswith", strEndsWith).ToObject()
 	dict["find"] = newBuiltinFunction("find", strFind).ToObject()
+	dict["isalnum"] = newBuiltinFunction("isalnum", strIsAlNum).ToObject()
+	dict["isalpha"] = newBuiltinFunction("isalpha", strIsAlpha).ToObject()
+	dict["isdigit"] = newBuiltinFunction("isdigit", strIsDigit).ToObject()
 	dict["join"] = newBuiltinFunction("join", strJoin).ToObject()
 	dict["lower"] = newBuiltinFunction("lower", strLower).ToObject()
 	dict["lstrip"] = newBuiltinFunction("lstrip", strLStrip).ToObject()
@@ -1136,6 +1187,18 @@ func toUpper(b byte) byte {
 	return b
 }
 
+func isAlNum(c byte) bool {
+	return isAlpha(c) || isDigit(c)
+}
+
+func isAlpha(c byte) bool {
+	return 'A' <= c && c <= 'Z' || 'a' <= c && c <= 'z'
+}
+
+func isDigit(c byte) bool {
+	return '0' <= c && c <= '9'
+}
+
 // strLeftPad returns s padded with fillchar so that its length is at least width.
 // Fillchar must be a single character. When fillchar is "0", s starting with a
 // sign are handled correctly.

runtime/str_test.go

@@ -356,6 +356,21 @@ func TestStrMethods(t *testing.T) {
 		{"find", wrapArgs("bar", "a", 0, -1), NewInt(1).ToObject(), nil},
 		{"find", wrapArgs("foo", newTestTuple("barfoo", "oo").ToObject()), nil, mustCreateException(TypeErrorType, "'find/index' requires a 'str' object but received a 'tuple'")},
 		{"find", wrapArgs("foo", 123), nil, mustCreateException(TypeErrorType, "'find/index' requires a 'str' object but received a 'int'")},
+		{"isalnum", wrapArgs("123abc"), True.ToObject(), nil},
+		{"isalnum", wrapArgs(""), False.ToObject(), nil},
+		{"isalnum", wrapArgs("#$%"), False.ToObject(), nil},
+		{"isalnum", wrapArgs("abc#123"), False.ToObject(), nil},
+		{"isalnum", wrapArgs("123abc", "efg"), nil, mustCreateException(TypeErrorType, "'isalnum' of 'str' requires 1 arguments")},
+		{"isalpha", wrapArgs("xyz"), True.ToObject(), nil},
+		{"isalpha", wrapArgs(""), False.ToObject(), nil},
+		{"isalpha", wrapArgs("#$%"), False.ToObject(), nil},
+		{"isalpha", wrapArgs("abc#123"), False.ToObject(), nil},
+		{"isalpha", wrapArgs("absd", "efg"), nil, mustCreateException(TypeErrorType, "'isalpha' of 'str' requires 1 arguments")},
+		{"isdigit", wrapArgs("abc"), False.ToObject(), nil},
+		{"isdigit", wrapArgs("123"), True.ToObject(), nil},
+		{"isdigit", wrapArgs(""), False.ToObject(), nil},
+		{"isdigit", wrapArgs("abc#123"), False.ToObject(), nil},
+		{"isdigit", wrapArgs("123", "456"), nil, mustCreateException(TypeErrorType, "'isdigit' of 'str' requires 1 arguments")},
 		{"join", wrapArgs(",", newTestList("foo", "bar")), NewStr("foo,bar").ToObject(), nil},
 		{"join", wrapArgs(":", newTestList("foo", "bar", NewUnicode("baz"))), NewUnicode("foo:bar:baz").ToObject(), nil},
 		{"join", wrapArgs("nope", NewTuple()), NewStr("").ToObject(), nil},