But it doesn't close the file. And there is no way to close it after
that statement since there is no reference to the stream object. Now,
in most cases, not closing the stream is not a problem as ooRexx will do
it when the program ends. But if you need to access the same file again
later in the program, having the stream still open is problematic, no?
Gil
On 6/15/2024 8:02 PM, Rick McGuire wrote:
Um,
a = .stream~new(filename)~arrayin
is a one liner that reads into an array.
Rick
On Sat, Jun 15, 2024 at 7:50 PM Gilbert Barmwater
<gi...@bellsouth.net> wrote:
First let me offer the following way to write the contents of an
array to a stream that only requires a single line:
.stream~new(streamFileName)~~arrayOut(arr [,Lines|Chars])~close
Unfortunately, there is no corresponding "one-liner" for reading
the contents of a stream into an array. This lack of "symmetry"
has always bothered me and I have experimented over the years with
possible solutions. Not too long ago I was able to devise a way
to finally accomplish it.
Before I reveal it, let me note that the above comments are
equally applicable to charOut/charIn and lineOut/lineIn should one
wish to deal with character(s) or a single line of output/input.
My solution is to add additional instance methods to the .stream
class named arrayInto, charInto and lineInto. The difference
between them and the similar *In methods is that the first
argument is a variable reference followed by the "standard" *In
arguments. These methods perform the operation of the related *In
method and then assign the data - array, character(s) or line - to
the value of the variable reference. So the corresponding
"one-liner" for reading the contents of a stream into an array is:
.stream~new(streamFileName)~~arrayInto(>arr, [Lines|Chars] )~close
But, you might say, ooRexx doesn't allow you to "add" methods to
the pre-defined classes like .stream. That is not strictly true
and there are several ways around that. I had planned to talk
about that as part of a planned presentation at the Vienna
Symposium next May but, since the subject has come up now, it
looks like I will need to reveal it ahead of time.
On a more general, philosophical note, I prefer to find solutions
that do NOT require adding classes, methods, or functions to the
base ooRexx but that can be included with a ::requires statement,
similar to the way that, e.g. RxMath functions are handled. I
guess that goes back to the original Rexx idea of keeping the
language small but is also consistent with how other languages
provide "libraries" of added functionality.
If anyone is interested in the implementation of the arryInto
method, I will post it here and, if not, will discuss it during
the Symposium.
Gil
On 6/15/2024 2:38 PM, Rony G. Flatscher wrote:
The Stream class has the handy instance methods arrayIn and arrayOut.
To read the content of a stream into an array the following
statements are necessary:
s=.stream~new(streamFileName)
s~open( [read|both] )
arr=s~arrayIn( [Lines|Chars] )
s~close
To write the content of an array into a stream the following
statements are necessary:
s=.stream~new(streamFileName)
s~open( [write | both [append|replace]] )
s~arrayOut(arr [,Lines|Chars])
s~close
---
It would be very handy, if the Stream class also offered as class
methods arrayIn and arrayOut that would allow one single
statement to read from any stream (file) into an array or to
write an array to any stream (file).
class method arrayIn:
arr=.stream~arrayIn( streamFileName [,Lines|Chars] ) -- default: Lines
and
class method arrayOut:
.stream~arrayOut(streamFileName , arr [,append|replace] [,Lines|Chars]
) -- default: append, Lines
What do you think?
Would you see any problems and if so which ones?
---rony
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