[erlang-questions] How to detect \. in Markdown string

[Richard A. O'Keefe]

> On 21/06/2017, at 5:03 PM, <lloyd@REDACTED> <lloyd@REDACTED> wrote:
> 
> But darned if I can find an Erlang function to distinguish these two cases:
> 
> 2> S = "1986\. What a great season.".
> "1986. What a great season."

\. is just dot.  If you want a \ in there, you need \\.

T = "1986\\. What a great season."


> 3> 
> 3> string:chr(S, "\.").

As the name suggests, string:chr wants a *character* as
its second argument.  You have given it a *string*.

1> T = "1986\\. What a great season.".
"1986\\. What a great season."
2> string:chr(T, $.).                
6
3> string:str(T, "\\.").
5

The Erlang reference manual, section 3.15, lists all the
defined character escape sequences.  Anything NOT in
that list is NOT a defined escape sequence and you use
it at your peril.  It is a pity that sequences like \.
and \E are not reported as errors or at least warnings.