def eval(self, context):
if self.expression is None:
return js.Completion(js.RETURN, js.UNDEFINED, js.EMPTY)
else:
return js.Completion(js.RETURN,
js.get_value(self.expression.eval(context)),
js.EMPTY)
def eval(self, context):
if self.expression is None:
return js.Completion(js.RETURN, js.UNDEFINED, js.EMPTY)
else:
item = self.expression.eval(context)
if type(item) is js.Completion:
item = item.value
return js.Completion(js.RETURN, item, js.EMPTY)
def eval(self, context):
result_value = js.EMPTY
while True:
condition_value = js.get_value(self.condition.eval(context))
if not condition_value:
return js.Completion(js.NORMAL, result_value, js.EMPTY)
stmt = self.statement.eval(context)
if stmt.value is not js.EMPTY:
result_value = stmt.value
if stmt.type is js.BREAK:
return js.Completion(js.NORMAL, result_value, js.EMPTY)
elif js.is_abrupt(stmt) and stmt.type is not js.CONTINUE:
return stmt
def test_closure(self):
program = """var fibgen = function () {
var a = 0, b = 1;
return function () {
var old = a;
a = b;
b = b + old;
return old;
};
};
var fib = fibgen();
var f1 = fib();
var f2 = fib();
fib(); fib(); fib(); fib();
var f7 = fib();
fib(); fib(); fib(); fib();
var fib2 = fibgen();
fib2(); fib2(); fib2(); fib2();
var f5 = fib2();
fib(); // f12
"""
context = js.ExecutionContext({})
self.assertEqual(self.eval(program, context),
js.Completion(js.NORMAL, 89, js.EMPTY))
self.assertEqual(context['f1'], 0)
self.assertEqual(context['f2'], 1)
self.assertEqual(context['f5'], 3)
self.assertEqual(context['f7'], 8)
def test_modify_global_variable(self):
program = """var x = 1, incrementX = function () { x += 1; };
incrementX();
incrementX();
x;"""
self.assertEqual(self.eval(program),
js.Completion(js.NORMAL, 3, js.EMPTY))
def eval(self, context):
cntx = js.ExecutionContext(dict(), parent=context)
result_value = js.EMPTY
firstst = self.first.eval(cntx)
while True:
condition_value = js.get_value(self.condition.eval(cntx))
#print("COND",condition_value)
if not condition_value:
return js.Completion(js.NORMAL, result_value, js.EMPTY)
stmt = self.statement.eval(cntx)
if stmt.value is not js.EMPTY:
result_value = stmt.value
if stmt.type is js.BREAK:
return js.Completion(js.NORMAL, result_value, js.EMPTY)
elif js.is_abrupt(stmt) and stmt.type is not js.CONTINUE:
return stmt
nextst = self.then.eval(cntx)
def test_shadowing(self):
program = """var x = 1;
var shadow = function () {
var x = 3; x += 1; return x;
};
shadow();"""
context = js.ExecutionContext({})
self.assertEqual(self.eval(program, context), js.Completion(js.NORMAL, 4, js.EMPTY))
self.assertEqual(context['x'], 1)
def test_dangling_else(self):
stmt = """if (false)
if (true) 3;
else 5;"""
self.assertEqual(self.eval(stmt), js.EMPTY_COMPLETION)
stmt = """if (true)
if (true) 3;
else 5;"""
self.assertEqual(self.eval(stmt), js.Completion(js.NORMAL, 3, js.EMPTY))
def test_continue_statement(self):
stmt = """while (x < 10) {
++x;
if (x % 2 == 0)
continue;
++y;
}"""
context = js.ExecutionContext({'x': 0, 'y': 0})
self.assertEqual(self.eval(stmt, context), js.Completion(js.NORMAL, 5, js.EMPTY))
self.assertEqual(context['x'], 10)
self.assertEqual(context['y'], 5)
def test_console_object(self):
program = """var i = 0;
while (i < 10) {
console.log(i);
i++;
}
"""
out = StringIO()
context = js.ExecutionContext({'console': js.Console(out=out)})
self.assertEqual(self.eval(program, context), js.Completion(js.NORMAL, 9, js.EMPTY))
self.assertEqual(out.getvalue(), "0.0\n1.0\n2.0\n3.0\n4.0\n5.0\n6.0\n7.0\n8.0\n9.0\n")
def test_break_statement(self):
stmt = """while (x < 10) {
++x;
if (x % 3 == 0)
break;
++y;
}"""
context = js.ExecutionContext({'x': 0, 'y': 0})
self.assertEqual(self.eval(stmt, context), js.Completion(js.NORMAL, 2, js.EMPTY))
self.assertEqual(context['x'], 3)
self.assertEqual(context['y'], 2)
def eval(self, context):
return js.Completion(js.NORMAL,
js.get_value(self.expression.eval(context)),
js.EMPTY)
def eval(self, context):
ref = self.identifier.eval(context)
value = js.get_value(self.initialiser.eval(context))
js.put_value(ref, value)
return js.Completion(js.NORMAL, ref.name, js.EMPTY)
def test_block(self):
self.assertEqual(self.eval('{ 1; 3; }'),
js.Completion(js.NORMAL, 3, js.EMPTY))
def test_expression_statement(self):
self.assertEqual(self.eval('1 + 2 * 7;'),
js.Completion(js.NORMAL, 15, js.EMPTY))
def test_if_statement(self):
self.assertEqual(self.eval('if (2 + 2 == 4) 3;'),
js.Completion(js.NORMAL, 3, js.EMPTY))
self.assertEqual(self.eval('if (false) 3;'), js.EMPTY_COMPLETION)
def eval(self, context):
return js.Completion(js.BREAK, js.EMPTY, js.EMPTY)
def test_arguments(self):
program = """var sqr = function (x) { return x * x; };
sqr(7);"""
self.assertEqual(self.eval(program),
js.Completion(js.NORMAL, 49, js.EMPTY))
def test_function_as_variable(self):
program = """var f = function () { return 42; };
f();"""
self.assertEqual(self.eval(program),
js.Completion(js.NORMAL, 42, js.EMPTY))
def test_while_statement(self):
context = js.ExecutionContext({'x': 3})
self.assertEqual(self.eval('while (x < 5) ++x;', context),
js.Completion(js.NORMAL, 5, js.EMPTY))
self.assertEqual(context['x'], 5)
def test_do_while_statement(self):
context = js.ExecutionContext({'x': 3})
self.assertEqual(self.eval('do ++x; while (x < 3);', context),
js.Completion(js.NORMAL, 4, js.EMPTY))
self.assertEqual(context['x'], 4)
def test_if_else_statement(self):
self.assertEqual(self.eval('if (false) 3; else 5;'),
js.Completion(js.NORMAL, 5, js.EMPTY))
def test_function_as_argument(self):
program = """var double = function (f, x) { return f(f(x)); };
double(function (x) { return x * x; }, 2);"""
self.assertEqual(self.eval(program),
js.Completion(js.NORMAL, 16, js.EMPTY))
def eval(self, context):
return js.Completion(js.CONTINUE, js.EMPTY, js.EMPTY)
def test_nested_blocks(self):
self.assertEqual(self.eval('{ 1; {3; 2;}}'),
js.Completion(js.NORMAL, 2, js.EMPTY))
def test_return_statement(self):
program = """function () { return 4; 7; } ();"""
self.assertEqual(self.eval(program),
js.Completion(js.NORMAL, 4, js.EMPTY))
def test_block_with_empty_statements(self):
self.assertEqual(self.eval('{7;;}'),
js.Completion(js.NORMAL, 7, js.EMPTY))
