String reboot - (1a) incidental whitespace

[Jim Laskey]

I pushed changes to http://hg.openjdk.java.net/amber/amber <http://hg.openjdk.java.net/amber/amber> string-tapas branch to reflect the incidental whitespace discussion. What is implemented is what Brian described as 

Version 2 of the algorithm — the “significant closing delimiter” version — is:
 - Strip leading and trailing blanks (perhaps limited to one each only)
 - Compute the maximal common whitespace prefix of the remaining lines, _including the stripped trailing blank line from above, if any_, and trim that off
 - If a blank last line was trimmed, add back a newline

With strip leading and trailing blanks limited to one each.

I also added a "super escape" \~ to opt out of auto align.


Example:

        String l = """\~
                       +--------+
                       |  text  |
                       +--------+
                   """; // what opt out might look like

Actual:

\n
.......................+--------+\n
.......................|  text  |\n
.......................+--------+\n
...................


Note that the String#align needs tweaking to reflect the algorithm (needs to add closing delimiter influence).

There is a sampler at http://cr.openjdk.java.net/~jlaskey/Strings/AutoAlign.java <http://cr.openjdk.java.net/~jlaskey/Strings/AutoAlign.java> (included below as well) that shows the examples from my original (1a) incidental whitespace e-mail.

Cheers,

-- Jim

_____________________________________________________________________________________________________________

public class AutoAlign {
    public static void report(String label, String result) {
        System.out.format("Result of variable %s%n", label);
        String formatted = result.replaceAll(" ", ".")
                                 .replaceAll("\n", "\\\\n\n");
        System.out.format("%s%n%n", formatted);
    }

    public static void main(String... args) throws Exception {
        String a = """
                   +--------+
                   |  text  |
                   +--------+
                   """; // first characters in first column?

        String b = """
                       +--------+
                       |  text  |
                       +--------+
                   """; // first characters in first column or indented four spaces?

        String c = """
                       +--------+
                       |  text  |
                       +--------+
        """; // first characters in first column or indented several?

        String d = """
            +--------+
            |  text  |
            +--------+
        """; // first characters in first column or indented four?

        String e =
        """
        +--------+
        |  text  |
        +--------+
        """; // heredoc?

        String f = """


                       +--------+
                       |  text  |
                       +--------+


                   """; // one or all leading or trailing blank lines stripped?

        String g = """
                      +--------+
                      |  text  |
                      +--------+"""; // Last \n dropped

        String h = """+--------+
                      |  text  |
                      +--------+"""; // determine indent of first line using scanner knowledge?

        String i = """  "nested"  """; // strip leading/trailing space?

        String name = " methodName";
        String j = ("""
                         public static void """ + name + """(String... args) {
                             System.out.println(String.join(args));
                         }
                   """).align(); // how do we handle expressions with multi-line strings?

        String k = String.format("""
                         public static void %s(String... args) {
                             System.out.println(String.join(args));
                         }
                   """, name); // is this the answer to  multi-line string expressions?

        String l = """\~
                       +--------+
                       |  text  |
                       +--------+
                   """; // what opt out might look like

        report("a", a);
        report("b", b);
        report("c", c);
        report("d", d);
        report("e", e);
        report("f", f);
        report("g", g);
        report("h", h);
        report("i", i);
        report("j", j);
        report("k", k);
        report("l", l);
    }
}

_____________________________________________________________________________________________________________

Result of variable a
+--------+\n
|..text..|\n
+--------+\n


Result of variable b
....+--------+\n
....|..text..|\n
....+--------+\n


Result of variable c
...............+--------+\n
...............|..text..|\n
...............+--------+\n


Result of variable d
....+--------+\n
....|..text..|\n
....+--------+\n


Result of variable e
+--------+\n
|..text..|\n
+--------+\n


Result of variable f
\n
\n
....+--------+\n
....|..text..|\n
....+--------+\n
\n
\n


Result of variable g
+--------+\n
|..text..|\n
+--------+

Result of variable h
+--------+\n
|..text..|\n
+--------+

Result of variable i
"nested"

Result of variable j
public.static.void.methodName(String....args).{\n
..........System.out.println(String.join(args));\n
......}\n


Result of variable k
......public.static.void..methodName(String....args).{\n
..........System.out.println(String.join(args));\n
......}\n


Result of variable l
\n
.......................+--------+\n
.......................|..text..|\n
.......................+--------+\n
...................





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