Print parse tree from CLI to terminal

[romani]

this this good task for new contributors.

in connection with Javadoc tree #652 we need a option to main CLI to print parse tree to output.
That will help a lot .

right now we are forced to use Swing gui for this.

it is not clear for now in what format to print a tree, need to be discussed.

[Vladlis]

I suggest to use the same format which is used in JavadocTreePrinter.
Example file:

package pack.test;

class A extends B {
    final static String CONSTANT = "This is constant";

    private void foo(String x) { // comment
        foo(x);
    }
}

Result:

PACKAGE_DEF : [package]
|--ANNOTATIONS : [ANNOTATIONS]
|--DOT : [.]
    |--IDENT : [pack]
    |--IDENT : [test]
|--SEMI : [;]
CLASS_DEF : [CLASS_DEF]
|--MODIFIERS : [MODIFIERS]
|--LITERAL_CLASS : [class]
|--IDENT : [A]
|--EXTENDS_CLAUSE : [extends]
    |--IDENT : [B]
|--OBJBLOCK : [OBJBLOCK]
    |--LCURLY : [{]
    |--VARIABLE_DEF : [VARIABLE_DEF]
        |--MODIFIERS : [MODIFIERS]
            |--FINAL : [final]
            |--LITERAL_STATIC : [static]
        |--TYPE : [TYPE]
            |--IDENT : [String]
        |--IDENT : [CONSTANT]
        |--ASSIGN : [=]
            |--EXPR : [EXPR]
                |--STRING_LITERAL : ["This is constant"]
        |--SEMI : [;]
    |--METHOD_DEF : [METHOD_DEF]
        |--MODIFIERS : [MODIFIERS]
            |--LITERAL_PRIVATE : [private]
        |--TYPE : [TYPE]
            |--LITERAL_VOID : [void]
        |--IDENT : [foo]
        |--LPAREN : [(]
        |--PARAMETERS : [PARAMETERS]
            |--PARAMETER_DEF : [PARAMETER_DEF]
                |--MODIFIERS : [MODIFIERS]
                |--TYPE : [TYPE]
                    |--IDENT : [String]
                |--IDENT : [x]
        |--RPAREN : [)]
        |--SLIST : [{]
            |--EXPR : [EXPR]
                |--METHOD_CALL : [(]
                    |--IDENT : [foo]
                    |--ELIST : [ELIST]
                        |--EXPR : [EXPR]
                            |--IDENT : [x]
                    |--RPAREN : [)]
            |--SEMI : [;]
            |--RCURLY : [}]
    |--RCURLY : [}]

[romani]

We need line number and column number, please put them in "[]".

[romani]

What if we draw a tree as tool http://lintut.com/use-tree-command-in-linux/ do this ? That tool is famous so we could reuse its experience in drawing a tree.

[Vladlis]

OK
Please, pay attention on how line breaks are displayed.
Source:

class A {
    public static final String CONSTANT = "This
           is
           constant";
}

Result:

CLASS_DEF -> CLASS_DEF [1:0]
|--MODIFIERS -> MODIFIERS [1:0]
|--LITERAL_CLASS -> class [1:0]
|--IDENT -> A [1:6]
`--OBJBLOCK -> OBJBLOCK [1:8]
    |--LCURLY -> { [1:8]
    |--VARIABLE_DEF -> VARIABLE_DEF [2:4]
    |   |--MODIFIERS -> MODIFIERS [2:4]
    |   |   |--LITERAL_PUBLIC -> public [2:4]
    |   |   |--LITERAL_STATIC -> static [2:11]
    |   |   `--FINAL -> final [2:18]
    |   |--TYPE -> TYPE [2:24]
    |   |   `--IDENT -> String [2:24]
    |   |--IDENT -> CONSTANT [2:31]
    |   |--ASSIGN -> = [2:40]
    |   |   `--EXPR -> EXPR [2:42]
    |   |       `--STRING_LITERAL -> "This\n           is\n           constant" [2:42]
    |   `--SEMI -> ; [2:82]
    `--RCURLY -> } [3:0]

[romani]

looks good, but I still do not see a reason to use simple symbols "`" instead pseudo graphics "└" (extended ascii symbols) http://www.asciitable.com/

~/.../checkstyle/checks [master|✔] $ tree
├── AbstractDeclarationCollector.java
├── AbstractFormatCheck.java
├── AbstractOptionCheck.java
├── AbstractTypeAwareCheck.java
├── annotation
│   ├── AnnotationLocationCheck.java
│   ├── AnnotationUseStyleCheck.java
│   ├── MissingDeprecatedCheck.java
│   ├── MissingOverrideCheck.java
│   ├── PackageAnnotationCheck.java
│   ├── package-info.java
│   └── SuppressWarningsCheck.java
├── ArrayTypeStyleCheck.java
├── AvoidEscapedUnicodeCharactersCheck.java
├── blocks
│   ├── AvoidNestedBlocksCheck.java
│   ├── BlockOption.java
│   ├── EmptyBlockCheck.java

[Vladlis]

When I try to print such a symbol right from IntelliJ IDEA under Windows I get в”” .
Even though it works OK, when I use jar, it makes development platform- or locale- or smth else- dependent.

[romani]

@Vladlis , if that is a problems with output in IntelijIdea+windows only and it does not brake UTs execution in such IDE - we could ignore that problem. I doubt that smb will run this from IDE.

[Vladlis]

when I say "from IDE" I mean while running tests too

[romani]

@Vladlis , are UTs failing when extended ascii symbols are used (in code and in UT test method) ?

[Vladlis]

@romani
Yes: https://ci.appveyor.com/project/Checkstyle/checkstyle/build/3469/job/q6d2d6f65b63y24p#L706
And the same commit is has passed Travis https://travis-ci.org/checkstyle/checkstyle/jobs/106084053

[Vladlis]

Well, looks like pseudo graphics is not the reason of the failure:
https://ci.appveyor.com/project/Checkstyle/checkstyle/build/3470/job/a1evc16n02prai9c#L706

[Vladlis]

I've solved the problem locally by fixing line endings, but it still did not pass Appveyor until I replaced non-ASCII symbols.

[romani]

do you mean "ASCII extended" by "non-ASCII" ?

Different behaviour likely relate to different locales and charsets. Some pain is shared at http://stackoverflow.com/questions/388490/unicode-characters-in-windows-command-line-how , there more other links to problem.
Please confirm that after changing a charset it works. If it works we leave it as comment and stay with simple ASCII codes.

[Vladlis]

Changing charset does not work for Appveyor:
https://ci.appveyor.com/project/Checkstyle/checkstyle/build/3491/job/si1rx5hpciltraof#L50
https://ci.appveyor.com/project/Checkstyle/checkstyle/build/3491/job/si1rx5hpciltraof#L703

And test suddenly failed on my local machine, so usage of such symbols seems to be unstable for Windows:

I'll use an ASCII symbol and put a comment in code.

[romani]

Due to unstable behaviour of different instances of Windows, we will not use ascii extended symbols.
Code should be be compilable and run out of the box on all OS.

but some Windows do show symbols correctly:

Microsoft Windows [Version 6.1.7601]
Copyright (c) 2009 Microsoft Corporation.  All rights reserved.

C:\Users\rivanov>java -version
java version "1.8.0_71"
Java(TM) SE Runtime Environment (build 1.8.0_71-b15)
Java HotSpot(TM) Client VM (build 25.71-b15, mixed mode, sharing)

C:\Users\rivanov>cd
C:\Users\rivanov

C:\Users\rivanov>cd C:\Users\rivanov\Downloads

C:\Users\rivanov\Downloads>java -jar checkstyle-6.16-SNAPSHOT-all.jar -t MyClass
.java
CLASS_DEF -> CLASS_DEF [1:0]
|--MODIFIERS -> MODIFIERS [1:0]
|--LITERAL_CLASS -> class [1:0]
|--IDENT -> MyClass [1:6]
└--OBJBLOCK -> OBJBLOCK [1:14]
    |--LCURLY -> { [1:14]
    |--VARIABLE_DEF -> VARIABLE_DEF [2:1]
    |   |--MODIFIERS -> MODIFIERS [2:1]
    |   |   └--LITERAL_PRIVATE -> private [2:1]
    |   |--TYPE -> TYPE [2:9]
    |   |   └--LITERAL_INT -> int [2:9]
    |   |--IDENT -> value [2:13]
    |   └--SEMI -> ; [2:18]
    └--RCURLY -> } [3:0]

C:\Users\rivanov\Downloads>chcp
Active code page: 437

C:\Users\rivanov\Downloads>

[romani]

code is merged, issue is closed.