🚀 go-pugleaf

In article <EIVERSON.91Apr19200202@aigyptos.nmsu.edu> eiverson@nmsu.edu (Eric Iverson) writes:
>Can you think of a way to do this which does not involve writing to,
>reading from, and then removing a file?  The current routine is rather
>slow.  Is there some way that I could just open up a stream, write
>things to it, and then read from it?

The string streams available in Sepia have proven to be a very useful
feature to implement such types of algorithms. They basically allow the user to
write data into a string and read it back or modify. It then looks like

	:- open(S, string, s),		% open the stream s into the string S
	   write(s, Data),		% write Data there
	   seek(s, 0),			% start reading from the beginning
	   read(s, NewData),		% read the written stuff back
	   close(s).			% get rid of the string stream

Sepia has also a built-in predicate term_string(?Term, ?String) which
makes the conversion between any term and its string form, which is
implemented using string streams. The advantage of using string streams
over pipes is that the string streams are completely processed withing the
Prolog system, without system calls, and the current form of the string
can be always obtained with :- current_stream(String, string, s).
Note that although one can also write into a given string, e.g. with
	:- open("abcdef", string, s),
	   put(s, 0'b).
the original string is not destructed, and so the logical semantics
is preserved.

--Micha
--
E-MAIL  micha@ecrc.de            	MAIL	Micha Meier
						ECRC, Arabellastr. 17
                     				8000 Munich 81
						Germany