Erlang lists with single numbers over 8?

In some weird way all the numbers over 8, single, in a list becomes some kind of ASCII?

[8] -> ["\b"]

Please try to help me with this one :)

String is not a data type in Erlang, it's just a list of integers. But Erlang shell try to display lists as strings if possible:

1> S = [65, 66, 67, 68, 69, 70].
"ABCDEF"
2> S = "ABCDEF".
"ABCDEF"
3> io:write(S).
[65,66,67,68,69,70]ok
4> [65, 66].
"AB"
5> [65, 66, 1].
[65,66,1]

Print it with ~w instead of ~p, and your issue should go away.

~p tries to interpret the elements in the list as ASCII. ~w does not.

From documentation: http://www.erlang.org/doc/reference_manual/data_types.html

2.11 String

Strings are enclosed in double quotes ("), but is not a data type in Erlang. Instead a string "hello" is shorthand for the list [$h,$e,$l,$l,$o], that is [104,101,108,108,111].

Two adjacent string literals are concatenated into one. This is done at compile-time and does not incur any runtime overhead. Example:

"string" "42"

is equivalent to

"string42"