def Call_if_with_a_nonnumber_is_an_error():
assert_fails(
"Only numbers may be passed to an if, but I was passed " +
"'('string', 'x')'", evald, 'if("x", {}, {});')
def assert_prog_fails(program, error, env=None):
assert_fails(error, evald, program, env)
def Calling_set_with_nonstring_is_an_error():
assert_fails(
"set() takes a string as its first argument, but was: " +
"('number', 3.0)", evald, "x = 3; set(x, 4);")
def assert_prog_fails(program, error, env=None):
assert_fails(error, evald, program, env)