Re: [Chicken-users] Fwd: Peeking N characters in string ports

[Jörg F . Wittenberger]

Hi David,

On Jan 11 2019, David Ireland wrote:

> Hi there,
>
> I'm reading from a (string) port and have a need to peek 2 characters
> inside without actually reading off the port (read-char).
>
> I believe procedures such as unread-char seen in other Schemes would solve
> my problem however, this isn't available in Chicken it seems.

I do not recall that I ever used unread-char ever. I roughly recall that it 
usually can only "un-read" a single character. But that might be wrong.

> Would anyone have any suggestions?

If you really need such a thing, my only suggestion would be to look into
http://wiki.call-cc.org/man/5/Module%20(chicken%20port)

make-input-port combined with make-concatenated-port and some tricks could 
do the trick.

Best

/Jörg