stdlib/builtin: add quit and exit

In CPython's REPL, there are other ways to `quit` or `exit` the REPL without calling a function (by simply typing `quit` or `exit`). These names are injected via `site.py`. Since GPython does not have a site.py, this REPL usage is not implemented.

Fixes #140.

Author: aisk

stdlib/builtin/builtin.go

@@ -40,6 +40,7 @@ func init() {
 		py.MustNewMethod("divmod", builtin_divmod, 0, divmod_doc),
 		py.MustNewMethod("eval", py.InternalMethodEval, 0, eval_doc),
 		py.MustNewMethod("exec", py.InternalMethodExec, 0, exec_doc),
+		py.MustNewMethod("exit", builtin_exit, 0, exit_doc),
 		// py.MustNewMethod("format", builtin_format, 0, format_doc),
 		py.MustNewMethod("getattr", builtin_getattr, 0, getattr_doc),
 		py.MustNewMethod("globals", py.InternalMethodGlobals, 0, globals_doc),
@@ -61,6 +62,7 @@ func init() {
 		py.MustNewMethod("ord", builtin_ord, 0, ord_doc),
 		py.MustNewMethod("pow", builtin_pow, 0, pow_doc),
 		py.MustNewMethod("print", builtin_print, 0, print_doc),
+		py.MustNewMethod("quit", builtin_quit, 0, quit_doc),
 		py.MustNewMethod("repr", builtin_repr, 0, repr_doc),
 		py.MustNewMethod("round", builtin_round, 0, round_doc),
 		py.MustNewMethod("setattr", builtin_setattr, 0, setattr_doc),
@@ -1262,6 +1264,35 @@ func builtin_input(self py.Object, args py.Tuple) (py.Object, error) {
 	return line, nil
 }
 
+const exit_doc = `exit([status])
+
+Exit the interpreter by raising SystemExit(status).`
+
+const quit_doc = `quit([status])
+
+Alias for exit().`
+
+func builtin_exit(self py.Object, args py.Tuple) (py.Object, error) {
+	return builtinExit("exit", args)
+}
+
+func builtin_quit(self py.Object, args py.Tuple) (py.Object, error) {
+	return builtinExit("quit", args)
+}
+
+func builtinExit(name string, args py.Tuple) (py.Object, error) {
+	var exitCode py.Object
+	err := py.UnpackTuple(args, nil, name, 0, 1, &exitCode)
+	if err != nil {
+		return nil, err
+	}
+	exc, err := py.ExceptionNew(py.SystemExit, args, nil)
+	if err != nil {
+		return nil, err
+	}
+	return nil, exc.(*py.Exception)
+}
+
 const locals_doc = `locals() -> dictionary
 
 Update and return a dictionary containing the current scope's local variables.`

stdlib/builtin/tests/builtin.py

@@ -79,6 +79,15 @@
 assert exec("b = a+100", glob) == None
 assert glob["b"] == 200
 
+doc="exit/quit"
+assertRaises(SystemExit, exit)
+assertRaises(SystemExit, exit, 0)
+assertRaises(SystemExit, exit, 3)
+assertRaises(SystemExit, quit)
+assertRaises(SystemExit, quit, "bye")
+assertRaises(TypeError, exit, 1, 2)
+assertRaises(TypeError, quit, 1, 2)
+
 doc="getattr"
 class C:
     def __init__(self):