« Return to Thread: Source.fromFile(file).getLines
RE: Source.fromFile(file).getLines
by Detering Dirk-2
::
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Sorry, I'm feeling a bit confused now ...
I thought that "\n" is a "line terminator", (at least the
one on *nix based systems).
So I would translate your sentence
> How would you tell apart a line that ends in "\n" with one
> that doesn't?
Into "How would you tell apart a line that ends in a line end
with one that doesn't?"
I now ask: How would tell that a stream of characters is a "line"
if not by the line end marker? (Beside eof/eos of course).
> The method getLines doesn't strip away any characters present in
> the file. Which, by the way, is pretty standard behavior.
So far ...
> In Perl, for instance, you need to "chomp"
> away newlines if you don't want them. Likewise, in Scala, you
> need to stripLineEnd newlines if you don't want them.
... so bad. Think of the regex pattern match problem discussed earlier
here. (You have to strip the line before matching with "^some$" or
use "(?s)^some$").
From a domain progger's view:
When reading a CSV file into excel I get the data into cells,
without the cell separator (the C in CSV).
So when calling getLine() I would expect to get the "line" without
the technical EOL detail. This may be added again if I write
"line" out to some file with write[Line|ln] or print[Line|ln],
like I get the comma again when exporting the data as CSV.
Same is true for every envelope data on underlying transport
layers. They are only present on that layer.
Looking at a stream from a char perspective I would
expect to see it.
Looking at it from a line perspective, it makes no sense to me.
Just my 2ct.
>
>
> On Thu, Jul 9, 2009 at 2:07 PM, Ricky Clarkson
> <ricky.clarkson@...> wrote:
>
>
> ricky@ricky-desktop:~$ cat test.scala
> import scala.io.Source
> import java.io.File
>
> object Main {
> def main(args: Array[String]) {
> for (line <- Source.fromFile(new
> File("test.scala")).getLines)
> print("("+line+")")
> }
> }
>
>
> ricky@ricky-desktop:~$ scalac test.scala
> ricky@ricky-desktop:~$ scala Main
> (import scala.io.Source
> )(import java.io.File
> )(
> )(object Main {
> )( def main(args: Array[String]) {
> )( for (line <- Source.fromFile(new
> File("test.scala")).getLines)
> )( print("("+line+")")
> )( }
> )(}
> )(
> )(
> )
>
> Note that I used print instead of println. I can't
> imagine it's a
> good thing to have line contain a line terminator of any kind.
>
> 2009/7/9 Daniel Sobral <dcsobral@...>:
>
> > No, not expected. I don't get that either. Try doing
> map(_ map(_ toInt)) to
> > the result of getLines. Maybe you are getting "\r\n"
> and confusing it with
> > "\n\n".
> >
> > On Thu, Jul 9, 2009 at 1:38 PM, Gilles SCOUVART
> <Gilles.SCOUVART@...>
> > wrote:
> >>
> >> Hello all,
> >>
> >> I was surprised to notice that using
> Source.fromFile(file).getLines on a
> >> file with empty lines, those were added to the
> previous non empty line.
> >> I.e. if the file contains this:
> >> ------
> >> test
> >>
> >>
> >> ------
> >> then getLines.next would return "test\n\n" (written
> java-echap-style).
> >> I expected it would iterate on three lines instead:
> "test", "", and "".
> >> This is a little bit annoying for pattern matching
> on full lines...
> >>
> >> Is this expected behaviour?
> >>
> >> Gilles Scouvart.
> >
> >
> > --
> > Daniel C. Sobral
> >
> > Something I learned in academia: there are three
> kinds of academic reviews:
> > review by name, review by reference and review by value.
> >
>
>
>
>
> --
> Ricky Clarkson
> Java Programmer, AD Holdings
> +44 1565 770804
> Skype: ricky_clarkson
> Google Talk: ricky.clarkson@...
>
>
>
>
>
> --
> Daniel C. Sobral
>
> Something I learned in academia: there are three kinds of
> academic reviews: review by name, review by reference and
> review by value.
>
>
I thought that "\n" is a "line terminator", (at least the
one on *nix based systems).
So I would translate your sentence
> How would you tell apart a line that ends in "\n" with one
> that doesn't?
Into "How would you tell apart a line that ends in a line end
with one that doesn't?"
I now ask: How would tell that a stream of characters is a "line"
if not by the line end marker? (Beside eof/eos of course).
> The method getLines doesn't strip away any characters present in
> the file. Which, by the way, is pretty standard behavior.
So far ...
> In Perl, for instance, you need to "chomp"
> away newlines if you don't want them. Likewise, in Scala, you
> need to stripLineEnd newlines if you don't want them.
... so bad. Think of the regex pattern match problem discussed earlier
here. (You have to strip the line before matching with "^some$" or
use "(?s)^some$").
From a domain progger's view:
When reading a CSV file into excel I get the data into cells,
without the cell separator (the C in CSV).
So when calling getLine() I would expect to get the "line" without
the technical EOL detail. This may be added again if I write
"line" out to some file with write[Line|ln] or print[Line|ln],
like I get the comma again when exporting the data as CSV.
Same is true for every envelope data on underlying transport
layers. They are only present on that layer.
Looking at a stream from a char perspective I would
expect to see it.
Looking at it from a line perspective, it makes no sense to me.
Just my 2ct.
>
>
> On Thu, Jul 9, 2009 at 2:07 PM, Ricky Clarkson
> <ricky.clarkson@...> wrote:
>
>
> ricky@ricky-desktop:~$ cat test.scala
> import scala.io.Source
> import java.io.File
>
> object Main {
> def main(args: Array[String]) {
> for (line <- Source.fromFile(new
> File("test.scala")).getLines)
> print("("+line+")")
> }
> }
>
>
> ricky@ricky-desktop:~$ scalac test.scala
> ricky@ricky-desktop:~$ scala Main
> (import scala.io.Source
> )(import java.io.File
> )(
> )(object Main {
> )( def main(args: Array[String]) {
> )( for (line <- Source.fromFile(new
> File("test.scala")).getLines)
> )( print("("+line+")")
> )( }
> )(}
> )(
> )(
> )
>
> Note that I used print instead of println. I can't
> imagine it's a
> good thing to have line contain a line terminator of any kind.
>
> 2009/7/9 Daniel Sobral <dcsobral@...>:
>
> > No, not expected. I don't get that either. Try doing
> map(_ map(_ toInt)) to
> > the result of getLines. Maybe you are getting "\r\n"
> and confusing it with
> > "\n\n".
> >
> > On Thu, Jul 9, 2009 at 1:38 PM, Gilles SCOUVART
> <Gilles.SCOUVART@...>
> > wrote:
> >>
> >> Hello all,
> >>
> >> I was surprised to notice that using
> Source.fromFile(file).getLines on a
> >> file with empty lines, those were added to the
> previous non empty line.
> >> I.e. if the file contains this:
> >> ------
> >> test
> >>
> >>
> >> ------
> >> then getLines.next would return "test\n\n" (written
> java-echap-style).
> >> I expected it would iterate on three lines instead:
> "test", "", and "".
> >> This is a little bit annoying for pattern matching
> on full lines...
> >>
> >> Is this expected behaviour?
> >>
> >> Gilles Scouvart.
> >
> >
> > --
> > Daniel C. Sobral
> >
> > Something I learned in academia: there are three
> kinds of academic reviews:
> > review by name, review by reference and review by value.
> >
>
>
>
>
> --
> Ricky Clarkson
> Java Programmer, AD Holdings
> +44 1565 770804
> Skype: ricky_clarkson
> Google Talk: ricky.clarkson@...
>
>
>
>
>
> --
> Daniel C. Sobral
>
> Something I learned in academia: there are three kinds of
> academic reviews: review by name, review by reference and
> review by value.
>
>
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