question about String.stripIndent method

[Chris T]

Jim, this was the information that somehow I was not able to wrap my mind
around:

"So it all comes down to the last line being blank or not blank. A blank
line becomes an empty line due to stripping of trailing blanks."

Any character inserted on the last line (ending with """) will actually
automatically make the whole string fill up with space till that character.
Thank you so much for the clarification!

All the best!
  Chris

On Sun, Jan 12, 2020 at 8:30 PM Jim Laskey <james.laskey at oracle.com> wrote:

> Chris,
>
> String::stripIndent might not be the routine you are looking for. It is
> provided to duplicate the actions performed by the compiler when processing
> a Text Block. To use String::stripIndent as a method to strip indentation
> in the way you might expect you might have to massage the input string.
>
> Note: using ····· to represent leading spaces
>
> To understand what is going on, reverse the process and image what the
> string looked like as a Text Block.
>
> The first case goes like this.
>
> String endsWithNewLine = """
> \s\s\s\s\s<- this line starts with 5 blank spaces.
> \s\s\s\s\s<- count again: 1, 2, 3, 4, 5
> ········""";
>
> String endsWithNewLineAfterStripIndent = """
> ·····<- this line starts with 5 blank spaces.
> ·····<- count again: 1, 2, 3, 4, 5
> """;
>
> In this case the first two lines start with 5 spaces and the last line has
> zero spaces because we stripped trailing spaces.
>
> So applying the rules, the last line dominates and the indentation doesn't
> change.
>
> ·····<- this line starts with 5 blank spaces.
> ·····<- count again: 1, 2, 3, 4, 5
>
>
> The last line still has zero spaces.
>
> The second case goes like this.
>
> String endsWithAsterisk = """
> ·····\s\s\s\s\s<- this line starts with 5 blank spaces.
> ·····\s\s\s\s\s<- count again: 1, 2, 3, 4, 5
> ········*""";
>
> String endsWithAsteriskAfterStripIndent = """
> <- this line starts with 5 blank spaces.
> <- count again: 1, 2, 3, 4, 5
> ···*""";
>
> Since there was no stripping of all characters on the last line, first two
> lines dominate and we get
>
> <- this line starts with 5 blank spaces.
> <- count again: 1, 2, 3, 4, 5
> ···*
>
> So it all comes down to the last line being blank or not blank. A blank
> line becomes an empty line due to stripping of trailing blanks.
>
> Cheers,
>
> -- Jim
>
>
>
> > On Jan 12, 2020, at 12:26 AM, Chris T <tech.meshter at gmail.com> wrote:
> >
> > Hi,
> >
> > I am working on an educational material about OpenJDK 14. Downloaded the
> > code, compiled it and while "playing" with the new features I found
> > something that seems to be inconsistent (maybe a bug?). So here we go:
> >
> > I defined this method:
> >  public void questionToOpenJDKPossibleBugOnStripIdent() {
> >
> >    String endsWithNewLine = """
> >        \s\s\s\s\s<- this line starts with 5 blank spaces.
> >        \s\s\s\s\s<- count again: 1, 2, 3, 4, 5
> >                """;
> >    System.out.println("The string ending with new lines looks like
> this:");
> >    System.out.println(endsWithNewLine);
> >
> >    System.out.println();
> >    System.out.println("If we call stripIndent, the white spaces are not
> > eliminated (maybe I misunderstand the concept of incidental white
> space):");
> >    System.out.println(endsWithNewLine.stripIndent());
> >
> >    String endsWithAsterisk = """
> >        \s\s\s\s\s<- this line starts with 5 blank spaces.
> >        \s\s\s\s\s<- count again: 1, 2, 3, 4, 5
> >                *""";
> >    System.out.println("The string ending with asterisk looks like
> this:");
> >    System.out.println(endsWithAsterisk);
> >
> >    System.out.println();
> >    System.out.println("If we call stripIndent, the white spaces ARE
> > eliminated (this seems to be inconsistent with the previous
> behaviour):");
> >    System.out.println(endsWithAsterisk.stripIndent());
> >  }
> >
> > If I run the code above, I get this output:
> > The string ending with new lines looks like this:
> >     <- this line starts with 5 blank spaces.
> >     <- count again: 1, 2, 3, 4, 5
> >
> >
> > If we call stripIndent, the white spaces are not eliminated (maybe I
> > misunderstand the concept of incidental white space):
> >     <- this line starts with 5 blank spaces.
> >     <- count again: 1, 2, 3, 4, 5
> >
> > The string ending with asterisk looks like this:
> >     <- this line starts with 5 blank spaces.
> >     <- count again: 1, 2, 3, 4, 5
> >        *
> >
> > If we call stripIndent, the white spaces ARE eliminated (this seems to be
> > inconsistent with the previous behaviour):
> > <- this line starts with 5 blank spaces.
> > <- count again: 1, 2, 3, 4, 5
> >   *
> >
> > I looked over the stripIdent code and found this line (which, after
> > debugging, turns out that "blocks" the entire indentation process):
> > boolean optOut = lastChar == '\n' || lastChar == '\r';
> >
> > Can somebody explain me what am I missing? Maybe there is an area din the
> > JEP documentation that clarifies this and I didn't see nor actively paid
> > attention to?
> >
> > Thanks!
> >  Chris T
>
>