def test_A_native_function_can_edit_the_environment():
def mx3(env):
env.set("x", NumberValue(3))
env = make_env()
env.set("make_x_three", NativeFunctionValue(mx3))
assert (evald("x=1 make_x_three() x", env) == NumberValue(3))
def test_A_closure_holds_updateable_values():
def dumb_set(env, sym, val):
env.parent().parent().parent().set(sym.value, val)
def dumb_if_equal(env, val1, val2, then_fn, else_fn):
if val1 == val2:
ret = then_fn
else:
ret = else_fn
return eval_cell_list([FunctionCallTree(ret, [])], env)
env = make_env()
env.set("dumb_set", NativeFunctionValue(dumb_set))
env.set("dumb_if_equal", NativeFunctionValue(dumb_if_equal))
assert (evald(
"""
counter={
x=0
{:(meth)
dumb_if_equal(
meth,
"get",
{x},
{dumb_set("x",x+1)}
)
}
}()
counter("inc")
counter("inc")
counter("get")
""", env) == NumberValue(2))
def test_Native_function_gets_called():
def native_fn(_env, x, y):
return NumberValue(x.value + y.value)
env = make_env()
env.set("native_fn", NativeFunctionValue(native_fn))
assert evald("native_fn(2,8)", env) == NumberValue(10)
def r(nv):
return NumberValue(round(nv.value))
def test_Get_wraps_around():
assert evald("Get([0,1,2,3,4],-1)") == NumberValue(4)
assert evald("Get([0,1,2,3,4],-2)") == NumberValue(3)
assert evald("Get([0,1,2,3,4],5)") == NumberValue(0)
assert evald("Get([0,1,2,3,4],6.1)") == NumberValue(1)
assert evald("Get([0,1,2,3,4],11)") == NumberValue(1)
def test_Calling_a_function_returns_its_last_value():
assert (evald("{10 11}()") == NumberValue(11))
def test_Negating_a_symbol():
assert evald("x=30 x=10 -x") == NumberValue(-10)
def test_Undefined_variables_are_equal_to_0():
assert evald("foo") == NumberValue(0)
def TODO_FAILS_test_Can_define_a_value_as_a_negative():
assert evald("x=-30 x") == NumberValue(-30)
def TODO_FAILS_test_Modifying_by_negative_numbers_comes_out_correct():
assert evald("r=3 r+=-4 r") == NumberValue(-1)
assert evald("r=3 r*=-4 r") == NumberValue(-12)
def test_Modifying_arithmetic_expressions_come_out_correct():
assert evald("r=3 r+=4 r") == NumberValue(7)
assert evald("r=3 r-=4 r") == NumberValue(-1)
assert evald("r=3 r*=4 r") == NumberValue(12)
assert evald("r=3 r/=4 r") == NumberValue(0.75)
def test_Evaluating_a_primitive_returns_itself():
assert evald("3") == NumberValue(3)
assert evald("3.1") == NumberValue(3.1)
assert evald("-3.1") == NumberValue(-3.1)
assert evald("'foo'") == StringValue("foo")
def native_fn3(_env, _x, _y, _z):
return NumberValue(12)
def native_fn0(_env):
return NumberValue(12)
def native_fn(_env, x, y):
return NumberValue(x.value + y.value)
def test_A_symbol_within_a_function_has_the_local_value():
assert (evald("""
foo=3
bar={foo=77 foo}()
bar
""") == NumberValue(77))
def test_Can_hold_a_reference_to_a_function_and_call_it():
assert (evald("""
add={:(x,y)x+y}
add(20,2.2)
""") == NumberValue(22.2))
def test_Body_of_a_function_can_use_arg_values():
assert (evald("{:(x,y)x+y}(100,1)") == NumberValue(101))
def test_Arithmetic_expressions_come_out_correct():
assert evald("3+4") == NumberValue(7)
assert evald("3-4") == NumberValue(-1)
assert evald("3*4") == NumberValue(12)
assert evald("3*-4") == NumberValue(-12)
assert evald("3/4") == NumberValue(0.75)
def mx3(env):
env.set("x", NumberValue(3))
def test_Modifying_uninitialised_variables_comes_out_correct():
assert evald("d+=4 d") == NumberValue(4)
def test_Array_literal():
assert (evald("[3,4]") == ArrayValue([NumberValue(3), NumberValue(4)]))
def test_Referring_to_an_unknown_symbol_yields_0():
assert evald("unkn") == NumberValue(0.0)
def test_Get_from_array():
assert evald("x=[3,4] Get(x,0)") == NumberValue(3)
def test_Can_define_a_value_and_retrieve_it():
assert evald("x=30 x ") == NumberValue(30)
assert evald("y='foo' y") == StringValue("foo")
def test_Get_from_array_literal():
assert evald("Get([3,4],1)") == NumberValue(4)
def test_Modifying_a_value_is_allowed():
assert evald("x=30 x=10 x") == NumberValue(10)
def test_Add_to_array_literal():
assert (evald("Add([3,4],1)") == ArrayValue([
NumberValue(3),
NumberValue(4),
NumberValue(1),
]))
def test_Value_of_an_assignment_is_the_value_assigned():
assert evald("x=31") == NumberValue(31)
def test_Negative_assignment():
assert evald("x=-31") == NumberValue(-31)