🚀 go-pugleaf

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From the reply of Constantine Rasmussen at Pixel Computer Incorporated:

>>It seems that job of read is not to keep you out of the control 
>>characters but to only give you a printable char for whatever it was
>>that you did read, ie, a blank.

Read and the other Pascal I/O routines should NOT suppress control (i.e.,
non-printable) characters. The only exception to this is if end of line
is represented on your processor by such a character (or sequence of
characters). Some systems use an "invisible" count to specify how many
characters are in each line (and therefore where the end of line is).

One of the few differences between the ANSI/IEEE and ISO Pascal Standards is
that the former allows the end of line to be represented by a value of type
char, while the ISO standard prohibits this.

>>                ...  As I understand Pascal, if you want to get past
>>eoln the classic way is "readln;" without any arguments. ...

True, if you actually don't want to read anything further on the current
input line. Otherwise, readln can take arguments just like read.

>>Likewise, if you're interested in reading the real chars in a line,
>>don't use read but just "get" from the file pointer.

There should be absolutely no difference between doing "read(f, ch)" and
"ch := f^; get(f)". Again, control characters should not be suppressed
(although many file systems suppress ASCII nuls and many text editors make it
nearly impossible to enter most of the control characters).

                                              Bob Dietrich
                                              Tektronix, Inc.
                                              (503) 629-1727
{ucb or dec}vax!tektronix!robertd             uucp address
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robertd.tektronix@rand-relay                  arpa address