def visit_ForNode(self, node, context):
res = RTResult()
start_value = res.register(self.visit(node.start_value_node, context))
if res.error: return res
end_value = res.register(self.visit(node.end_value_node, context))
if res.error: return res
if node.step_value_node:
step_value = res.register(self.visit(node.step_value_node,
context))
if res.error: return res
else:
step_value = Number(1)
i = start_value.value
if step_value.value >= 0:
condition = lambda: i < end_value.value
else:
condition = lambda: i > end_value.value
while condition():
context.symbol_table.set(node.var_name_tok.value, Number(i))
i += step_value.value
res.register(self.visit(node.body_node, context))
if res.error: return res
return res.success(None)
def visit_WhileNode(self, node, context):
res = RTResult()
while True:
condition = res.register(self.visit(node.condition_node, context))
if res.error: return res
if not condition.is_true(): break
res.register(self.visit(node.body_node, context))
if res.error: return res
return res.success(None)
def visit_CallNode(self, node, context):
res = RTResult()
args = []
value_to_call = res.register(self.visit(node.node_to_call, context))
if res.error: return res
value_to_call = value_to_call.copy().set_pos(node.pos_start,
node.pos_end)
for arg_node in node.arg_nodes:
args.append(res.register(self.visit(arg_node, context)))
if res.error: return res
return_value = res.register(value_to_call.execute(args))
if res.error: return res
return res.success(return_value)
def visit_VarAssignNode(self, node, context):
res = RTResult()
var_name = node.var_name_tok.value
value = res.register(self.visit(node.value_node, context))
if res.error: return res
context.symbol_table.set(var_name, value)
return res.success(value)
def visit_IfNode(self, node, context):
res = RTResult()
for condition, expr in node.cases:
condition_value = res.register(self.visit(condition, context))
if res.error: return res
if condition_value.is_true():
expr_value = res.register(self.visit(expr, context))
if res.error: return res
return res.success(expr_value)
if node.else_case:
else_value = res.register(self.visit(node.else_case, context))
if res.error: return res
return res.success(else_value)
return res.success(None)
def visit_BinOpNode(self, node, context):
res = RTResult()
left = res.register(self.visit(node.left_node, context))
if res.error: return res
right = res.register(self.visit(node.right_node, context))
if res.error: return res
if node.op_tok.type == TT_PLUS:
result, error = left.added_to(right)
elif node.op_tok.type == TT_MINUS:
result, error = left.subbed_by(right)
elif node.op_tok.type == TT_MUL:
result, error = left.multed_by(right)
elif node.op_tok.type == TT_DIV:
result, error = left.dived_by(right)
elif node.op_tok.type == TT_POW:
result, error = left.powed_by(right)
elif node.op_tok.type == TT_EE:
result, error = left.get_comparison_eq(right)
elif node.op_tok.type == TT_NE:
result, error = left.get_comparison_ne(right)
elif node.op_tok.type == TT_LT:
result, error = left.get_comparison_lt(right)
elif node.op_tok.type == TT_GT:
result, error = left.get_comparison_gt(right)
elif node.op_tok.type == TT_LTE:
result, error = left.get_comparison_lte(right)
elif node.op_tok.type == TT_GTE:
result, error = left.get_comparison_gte(right)
elif node.op_tok.matches(TT_KEYWORD, 'AND'):
result, error = left.anded_by(right)
elif node.op_tok.matches(TT_KEYWORD, 'OR'):
result, error = left.ored_by(right)
if error:
return res.failure(error)
else:
return res.success(result.set_pos(node.pos_start, node.pos_end))
def visit_UnaryOpNode(self, node, context):
res = RTResult()
number = res.register(self.visit(node.node, context))
if res.error: return res
error = None
if node.op_tok.type == TT_MINUS:
number, error = number.multed_by(Number(-1))
elif node.op_tok.matches(TT_KEYWORD, 'NOT'):
number, error = number.notted()
if error:
return res.failure(error)
else:
return res.success(number.set_pos(node.pos_start, node.pos_end))