def test_update(self):
st = SymbolTable()
self.assertRaises(AssertionError, st.update, "a", 1)
st.store("a", Expression(Type.int(), 1))
st.update("a", 2)
self.assertEqual(Type.int(), st.get_expression("a").type)
self.assertEqual(2, st.get_expression("a").value)
class Interpreter(Transformer):
def __init__(self, symbol_table):
super().__init__()
self.symbol_table = SymbolTable(
) if symbol_table is None else symbol_table
# def __default__(self, command, children, meta):
# logging.error("Ignoring unsupported command %s with children %s" % (command, children))
# raise Discard()
######## prog ########
def prog(self, children):
return children
######## commands ########
def commands(self, children):
return children
######## command ########
def takeoff(self, children) -> List[Command]:
return [Command.takeoff()]
def land(self, children) -> List[Command]:
return [Command.land()]
def up(self, children) -> List[Command]:
expr, = children
if expr.type != Type.int() and expr.type != Type.decimal():
raise CompileError(
"Expression {} should have type int or decimal, but is {}".
format(expr.value, expr.type))
return [Command.up(expr.value)]
def down(self, children) -> List[Command]:
expr, = children
if expr.type != Type.int() and expr.type != Type.decimal():
raise CompileError(
"Expression {} should have type int or decimal, but is {}".
format(expr.value, expr.type))
return [Command.down(expr.value)]
def left(self, children) -> List[Command]:
expr, = children
if expr.type != Type.int() and expr.type != Type.decimal():
raise CompileError(
"Expression {} should have type int or decimal, but is {}".
format(expr.value, expr.type))
return [Command.left(expr.value)]
def right(self, children) -> List[Command]:
expr, = children
if expr.type != Type.int() and expr.type != Type.decimal():
raise CompileError(
"Expression {} should have type int or decimal, but is {}".
format(expr.value, expr.type))
return [Command.right(expr.value)]
def forward(self, children) -> List[Command]:
expr, = children
if expr.type != Type.int() and expr.type != Type.decimal():
raise CompileError(
"Expression {} should have type int or decimal, but is {}".
format(expr.value, expr.type))
return [Command.forward(expr.value)]
def backward(self, children) -> List[Command]:
expr, = children
if expr.type != Type.int() and expr.type != Type.decimal():
raise CompileError(
"Expression {} should have type int or decimal, but is {}".
format(expr.value, expr.type))
return [Command.backward(expr.value)]
def rotate_left(self, children) -> List[Command]:
expr, = children
if expr.type != Type.int() and expr.type != Type.decimal():
raise CompileError(
"Expression {} should have type int or decimal, but is {}".
format(expr.value, expr.type))
return [Command.rotate_left(radians(expr.value))]
def rotate_right(self, children) -> List[Command]:
expr, = children
if expr.type != Type.int() and expr.type != Type.decimal():
raise CompileError(
"Expression {} should have type int or decimal, but is {}".
format(expr.value, expr.type))
return [Command.rotate_right(radians(expr.value))]
def wait(self, children) -> List[Command]:
expr, = children
if expr.type != Type.int() and expr.type != Type.decimal():
raise CompileError(
"Expression {} should have type int or decimal, but is {}".
format(expr.value, expr.type))
return [Command.wait(expr.value)]
def declare(self, children) -> List[Command]:
type, identifier = children
ident = identifier.ident
if ident in self.symbol_table:
raise CompileError("Identifier {} already declared".format(ident))
self.symbol_table.store(
ident, Expression(type, type.default_value, ident=ident))
return []
def declare_assign(self, children) -> List[Command]:
type, identifier, expr = children
ident = identifier.ident
if ident in self.symbol_table:
raise CompileError("Identifier {} already declared".format(ident))
if expr.type != type:
raise CompileError(
"Identifier {} has been declared as {}, but assigned as {}".
format(ident, type, expr.type))
expr_with_ident = Expression(expr.type, expr.value, ident)
self.symbol_table.store(ident, expr_with_ident)
return []
def assign_ident(self, children) -> List[Command]:
identifier, expr = children
ident = identifier.ident
if ident not in self.symbol_table:
raise CompileError(
"Identifier {} has not been declared".format(ident))
assigned_type = expr.type
declared_type = self.symbol_table.get_expression(ident).type
if assigned_type != declared_type:
raise CompileError(
"Identifier {} has been declared as {}, but assigned as {}".
format(ident, declared_type, assigned_type))
self.symbol_table.update(ident, expr.value)
return []
def _update_nested_ident(self, ident, expr, index) -> None:
if ident is not None:
if "[" in ident:
tokens = ident.split("[")
ident = tokens[0]
indices = [int(token.replace("]", "")) for token in tokens[1:]]
else:
indices = []
assert ident in self.symbol_table
new_list = self.symbol_table.get_expression(ident).value
curr = new_list
for i in indices:
curr = curr[i]
curr[index] = expr.value
self.symbol_table.update(ident, new_list)
def assign_list_elem(self, children) -> List[Command]:
list_elem, expr = children
ident = list_elem.ident
list = list_elem.container
index = list_elem.index
assigned_type = expr.type
declared_type = list.type.elem_type
if assigned_type != declared_type:
raise CompileError(
"Assigned value {} should have type {}, but is {}".format(
expr.value, declared_type, assigned_type))
self._update_nested_ident(ident, expr, index)
return []
def assign_vector_elem(self, children) -> List[Command]:
vector_elem, expr = children
ident = vector_elem.ident
vector = vector_elem.container
index = vector_elem.index
if expr.type != Type.decimal():
raise CompileError(
"Assigned value {} should have type decimal, but is {}".format(
expr.value, expr.type))
self._update_nested_ident(ident, expr, index)
return []
def repeat(self, children) -> List[Command]:
expr = children[0]
commands = children[1:]
if expr.type != Type.int():
raise CompileError(
"Expression {} should have type int, but is {}".format(
expr.value, expr.type))
times = expr.value
return commands * times
######## func ########
# TODO
######## func_command ########
# TODO
######## param_list ########
# TODO
######## func_call ########
# TODO
######## arg_list ########
# TODO
######## ident ########
def ident(self, children) -> Identifier:
ident = "".join([str(child) for child in children])
if ident in self.symbol_table:
return Identifier(str(ident),
self.symbol_table.get_expression(ident))
return Identifier(str(ident), None)
######## list_elem ########
def list_elem(self, children) -> ListElem:
expr1, expr2 = children
if not isinstance(expr1.type, ListType):
raise CompileError(
"Expression {} has type {} is not a list".format(
expr1, expr1.type))
if expr2.type != Type.int():
raise CompileError(
"Expression {} should have type int, but is {}".format(
expr2, expr2.type))
if expr2.value >= len(expr1.value):
raise CompileError(
"List {} has length {}, but has been assessed with out-of-range index {}"
.format(expr1.ident, len(expr1.value), expr2.value))
return ListElem(expr1.ident, expr1, expr2.value)
######## vector_elem ########
def vector_x(self, children) -> VectorElem:
expr, = children
if expr.type != Type.vector():
raise CompileError(
"Expression {} should have type vector, but is {}".format(
expr, expr.type))
return VectorElem(expr.ident, expr, 0)
def vector_y(self, children) -> VectorElem:
expr, = children
if expr.type != Type.vector():
raise CompileError(
"Expression {} should have type vector, but is {}".format(
expr, expr.type))
return VectorElem(expr.ident, expr, 1)
def vector_z(self, children) -> VectorElem:
expr, = children
if expr.type != Type.vector():
raise CompileError(
"Expression {} should have type vector, but is {}".format(
expr, expr.type))
return VectorElem(expr.ident, expr, 2)
######## type ########
def int_type(self, children) -> Type:
return Type.int()
def decimal_type(self, children) -> Type:
return Type.decimal()
def string_type(self, children) -> Type:
return Type.string()
def boolean_type(self, children) -> Type:
return Type.boolean()
def vector_type(self, children) -> Type:
return Type.vector()
def list_type(self, children) -> Type:
elem_type, = children
return Type.list_of(elem_type)
######## expr ########
def expr(self, children) -> Expression:
child, = children
assert isinstance(child, AbstractExpression)
if isinstance(child,
Identifier) and child.ident not in self.symbol_table:
# child.expression is None iff child.ident not in self.symbol_table
raise CompileError("Identifier {} has not been declared".format(
child.ident))
expr = child.to_expression()
assert expr is not None and isinstance(expr, Expression)
return expr
def int_expr(self, children) -> Expression:
signed_int, = children
return Expression(Type.int(), int(signed_int))
def decimal_expr(self, children) -> Expression:
signed_float, = children
return Expression(Type.decimal(), float(signed_float))
def string_expr(self, children) -> Expression:
escaped_string, = children
quotation_removed = str(escaped_string)[1:-1]
return Expression(Type.string(), quotation_removed)
def true_expr(self, children) -> Expression:
return Expression(Type.boolean(), True)
def false_expr(self, children) -> Expression:
return Expression(Type.boolean(), False)
def list(self, children) -> Expression:
exprs = children
if len(exprs) == 0:
return Expression(Type.empty_list(), [])
if not all(e.type == exprs[0].type for e in exprs):
raise CompileError(
"Elements in list {} should have the same type".format(exprs))
return Expression(Type.list_of(exprs[0].type),
[e.value for e in exprs])
def vector(self, children) -> Expression:
expr1, expr2, expr3 = children
for expr in [expr1, expr2, expr3]:
if expr.type != Type.decimal():
raise CompileError(
"Expression {} should have type decimal, but is {}".format(
expr, expr.type))
return Expression(Type.vector(),
[expr1.value, expr2.value, expr3.value])