Yes, lists are singly linked lists and must be iterated to the end to find out the length. That’s why list == [] is recommended over length(list) == 0.
Nicd
3
quda
JaniHur
[…] there doesn’t appear to be a modern language that has – what I would be willing to call – native support for JSON.
What do you think would Ballerina’s json type qualify?
https://ballerina.io/learn/distinctive-language-features/data/#json-type
Valid JSON is also valid Ballerina syntax.
0
smathy
No, the json type is still an internal structure that any JSON string has to be parsed into, there’s no automatic recognition of a string of JSON as JSON, ie. you still need to call: json foo = value:fromJsonString(the_string);.
0
ONeill
I dont know if you can do it with a guard but you should be able to do pattern matching in the function clause like
def func(%JSON{} = my_json), do: my_json
That way the function will only match when a JSON struct is passed in.
Edit:
defmodule Test do
defstruct hello: "world", field: 2
def func(%Test{} = my_struct) do
IO.puts("Test struct")
end
end
%Test{hello: "world", field: 2}
|>Test.func()
# Test struct
%{hello: "world", field: 2}
|> Test.func()
# ** (FunctionClauseError) no function clause matching in Test.func/1
0