Re: ooc-980713 & oo2c-1.3.8

["Eric W. Nikitin" <enikitin@apk.net>]

Ian Rae <ianrae@istar.ca> wrote:
> 1.3.8 works fine for all 3 eol types.
>
> one small gripe:
> ReadLine returns readAfterEnd on the last line of a text
> file if no eol exists for that line.  Since there is generally
> no guarantee of eol on the last line, especially for user-
> created files (it just depends whether you hit enter or not
> after typing the last line), this behaviour is a bit odd.
> Certainly gets() in C has more forgiving logic: "read until
> eol or eof".


The behavior of ReadLine that you describe matches the spec:

Method: `(R: Reader)' ReadLine `(VAR S: ARRAY OF CHAR)'
     Reads a sequence of characters into S until an end-of-line
     character is encountered, or the array S is full.  The end-of-line
     character is discarded and S is always terminated with `0X'.

     If the end of the channel is reached before encountering an
     end-of-line character, a `readAfterEnd' error occurs.

     If S is not large enough to hold the entire input, a
     `valueOutOfRange' error occurs.

(1)  Upon encountering an error, the value of S is undefined.

     *Please note:* If the channel is already positioned at an
     end-of-line character, this method returns an empty string.


However,

> This isn't a huge issue.  I can live with it since the implementation
> still returns the last line, but perhaps this issue should be put
> on a wish list and if lots of people raise it, then fix it in a later
> release.

(1) says that there is no valid way to read the last line if it is not
terminated by an EOL (even though, in the current implementation, S does
contain the value of the last line).  IMO, the spec should be changed to


Method: `(R: Reader)' ReadLine `(VAR S: ARRAY OF CHAR)'
     Reads a sequence of characters into S; reading continues until an
     end-of-line character is encountered, the array S is full, or R reaches
     the end of the channel.  The end-of-line character is discarded and S
     is always terminated with `0X'.

     If R is already positioned at an end-of-line character, 
     S returns as an empty string.

     If S is not large enough to hold the entire input, a
     `valueOutOfRange' error occurs; S returns with the sequence of
     characters that have been read so far (terminated by `0X').

     If R has already reached the end of the channel (i.e., there are no
     more characters left to read), a `readAfterEnd' error occurs and S
     returns as an empty string.



Eric