ANTLR parsing failures are not explained properly in error reports

[volodya-lombrozo]

I have the following program:

# Comment here.
[args] > app
  seq > @
   *
     "a" > a
     QQ.io.stdout
       a

I run the following command:

eoc dataize app --parser=0.38.4 --home-tag=0.38.4

I get:

EO objects registered in .eoc/eo-foreign.json
Assembling into .eoc
[ERROR] Failed to parse '/Users/lombrozo/Workspace/Playground/eo/hello/app.eo:4': [4:2] no viable alternative at input '# Comment here.\n[args] > app\n  INTseq > @\n   ': "   *"
[ERROR] Failed to parse '/Users/lombrozo/Workspace/Playground/eo/hello/.eoc/4-pull/org/eolang/io/stdin.eo:29': Comment must be at least 64 characters long
[ERROR] Failed to parse '/Users/lombrozo/Workspace/Playground/eo/hello/.eoc/4-pull/org/eolang/io/stdout.eo:29': Comment must end with dot
[ERROR] Failed to parse '/Users/lombrozo/Workspace/Playground/eo/hello/.eoc/4-pull/org/eolang/malloc.eo:29': Comment must end with dot
[ERROR] Failed to parse '/Users/lombrozo/Workspace/Playground/eo/hello/.eoc/4-pull/org/eolang/false.eo:29': Comment must be at least 64 characters long
[ERROR] Failed to parse '/Users/lombrozo/Workspace/Playground/eo/hello/.eoc/4-pull/org/eolang/io/stdin.eo:35': Comment must be at least 64 characters long
[ERROR] Failed to parse '/Users/lombrozo/Workspace/Playground/eo/hello/.eoc/4-pull/org/eolang/false.eo:38': Comment must be at least 64 characters long
[ERROR] Failed to parse '/Users/lombrozo/Workspace/Playground/eo/hello/.eoc/4-pull/org/eolang/rust.eo:29': Comment must be at least 64 characters long
[ERROR] Failed to parse '/Users/lombrozo/Workspace/Playground/eo/hello/.eoc/4-pull/org/eolang/int.eo:34': Comment must be at least 64 characters long
[ERROR] Failed to parse '/Users/lombrozo/Workspace/Playground/eo/hello/.eoc/4-pull/org/eolang/malloc.eo:108': Comment must be at least 64 characters long
[ERROR] Failed to parse '/Users/lombrozo/Workspace/Playground/eo/hello/.eoc/4-pull/org/eolang/int.eo:40': Comment must be at least 64 characters long
[ERROR] Failed to parse '/Users/lombrozo/Workspace/Playground/eo/hello/.eoc/4-pull/org/eolang/false.eo:41': Comment must be at least 64 characters long
[ERROR] Failed to parse '/Users/lombrozo/Workspace/Playground/eo/hello/.eoc/4-pull/org/eolang/int.eo:47': Comment must be at least 64 characters long
[ERROR] Failed to parse '/Users/lombrozo/Workspace/Playground/eo/hello/.eoc/4-pull/org/eolang/int.eo:53': Comment must be at least 64 characters long
[ERROR] Failed to parse '/Users/lombrozo/Workspace/Playground/eo/hello/.eoc/4-pull/org/eolang/while.eo:36': Comment must be at least 64 characters long
[ERROR] Failed to parse '/Users/lombrozo/Workspace/Playground/eo/hello/.eoc/4-pull/org/eolang/int.eo:56': Comment must be at least 64 characters long
[ERROR] Failed to parse '/Users/lombrozo/Workspace/Playground/eo/hello/.eoc/4-pull/org/eolang/malloc.eo:111': Comment must be at least 64 characters long
[ERROR] Failed to parse '/Users/lombrozo/Workspace/Playground/eo/hello/.eoc/4-pull/org/eolang/int.eo:62': Comment must be at least 64 characters long
[ERROR] Failed to parse '/Users/lombrozo/Workspace/Playground/eo/hello/.eoc/4-pull/org/eolang/int.eo:65': Comment must be at least 64 characters long
[ERROR] Failed to parse '/Users/lombrozo/Workspace/Playground/eo/hello/.eoc/4-pull/org/eolang/true.eo:29': Comment must be at least 64 characters long
[ERROR] Failed to parse '/Users/lombrozo/Workspace/Playground/eo/hello/.eoc/4-pull/org/eolang/int.eo:68': Comment must be at least 64 characters long
[ERROR] Failed to parse '/Users/lombrozo/Workspace/Playground/eo/hello/.eoc/4-pull/org/eolang/true.eo:38': Comment must be at least 64 characters long
[ERROR] Failed to parse '/Users/lombrozo/Workspace/Playground/eo/hello/.eoc/4-pull/org/eolang/tuple.eo:29': Comment must be at least 64 characters long
[ERROR] Failed to parse '/Users/lombrozo/Workspace/Playground/eo/hello/.eoc/4-pull/org/eolang/int.eo:71': Comment must be at least 64 characters long
[ERROR] Failed to parse '/Users/lombrozo/Workspace/Playground/eo/hello/.eoc/4-pull/org/eolang/true.eo:41': Comment must be at least 64 characters long
[ERROR] Failed to parse '/Users/lombrozo/Workspace/Playground/eo/hello/.eoc/4-pull/org/eolang/tuple.eo:31': Comment must be at least 64 characters long
[ERROR] Failed to parse '/Users/lombrozo/Workspace/Playground/eo/hello/.eoc/4-pull/org/eolang/int.eo:74': Comment must be at least 64 characters long
[ERROR] Failed to parse '/Users/lombrozo/Workspace/Playground/eo/hello/.eoc/4-pull/org/eolang/float.eo:34': Comment must be at least 64 characters long
[ERROR] Failed to parse '/Users/lombrozo/Workspace/Playground/eo/hello/.eoc/4-pull/org/eolang/tuple.eo:43': Comment must be at least 64 characters long
[ERROR] Failed to parse '/Users/lombrozo/Workspace/Playground/eo/hello/.eoc/4-pull/org/eolang/string.eo:34': Comment must be at least 64 characters long
[ERROR] Failed to parse '/Users/lombrozo/Workspace/Playground/eo/hello/.eoc/4-pull/org/eolang/float.eo:70': Comment must be at least 64 characters long
[ERROR] Failed to parse '/Users/lombrozo/Workspace/Playground/eo/hello/.eoc/4-pull/org/eolang/tuple.eo:48': Comment must be at least 64 characters long
[ERROR] Failed to parse '/Users/lombrozo/Workspace/Playground/eo/hello/.eoc/4-pull/org/eolang/string.eo:40': Comment must be at least 64 characters long
[ERROR] Failed to parse '/Users/lombrozo/Workspace/Playground/eo/hello/.eoc/4-pull/org/eolang/float.eo:77': Comment must be at least 64 characters long
[ERROR] Failed to parse '/Users/lombrozo/Workspace/Playground/eo/hello/.eoc/4-pull/org/eolang/tuple.eo:71': Comment must be at least 64 characters long
[ERROR] Failed to parse '/Users/lombrozo/Workspace/Playground/eo/hello/.eoc/4-pull/org/eolang/string.eo:43': Comment must be at least 64 characters long
[ERROR] Failed to parse '/Users/lombrozo/Workspace/Playground/eo/hello/.eoc/4-pull/org/eolang/float.eo:77': Comment must contain only ASCII printable characters: 0x20-0x7f
[ERROR] Failed to parse '/Users/lombrozo/Workspace/Playground/eo/hello/.eoc/4-pull/org/eolang/cage.eo:42': Comment must be at least 64 characters long
[ERROR] Failed to parse '/Users/lombrozo/Workspace/Playground/eo/hello/.eoc/4-pull/org/eolang/float.eo:84': Comment must be at least 64 characters long
[ERROR] Failed to parse '/Users/lombrozo/Workspace/Playground/eo/hello/.eoc/4-pull/org/eolang/cage.eo:45': Comment must be at least 64 characters long
[ERROR] Failed to parse '/Users/lombrozo/Workspace/Playground/eo/hello/.eoc/4-pull/org/eolang/float.eo:87': Comment must be at least 64 characters long
[ERROR] Failed to parse '/Users/lombrozo/Workspace/Playground/eo/hello/.eoc/4-pull/org/eolang/cage.eo:50': Comment must be at least 64 characters long
[ERROR] Failed to parse '/Users/lombrozo/Workspace/Playground/eo/hello/.eoc/4-pull/org/eolang/float.eo:87': Comment must contain only ASCII printable characters: 0x20-0x7f
[ERROR] Failed to parse '/Users/lombrozo/Workspace/Playground/eo/hello/.eoc/4-pull/org/eolang/float.eo:94': Comment must be at least 64 characters long
[ERROR] Failed to parse '/Users/lombrozo/Workspace/Playground/eo/hello/.eoc/4-pull/org/eolang/positive-infinity.eo:29': Comment must be at least 64 characters long
[ERROR] Failed to parse '/Users/lombrozo/Workspace/Playground/eo/hello/.eoc/4-pull/org/eolang/float.eo:97': Comment must be at least 64 characters long
[ERROR] Failed to parse '/Users/lombrozo/Workspace/Playground/eo/hello/.eoc/4-pull/org/eolang/nan.eo:29': Comment must be at least 64 characters long
[ERROR] Failed to parse '/Users/lombrozo/Workspace/Playground/eo/hello/.eoc/4-pull/org/eolang/positive-infinity.eo:33': Comment must be at least 64 characters long
[ERROR] Failed to parse '/Users/lombrozo/Workspace/Playground/eo/hello/.eoc/4-pull/org/eolang/float.eo:100': Comment must be at least 64 characters long
[ERROR] Failed to parse '/Users/lombrozo/Workspace/Playground/eo/hello/.eoc/4-pull/org/eolang/bytes.eo:33': Comment must be at least 64 characters long
[ERROR] Failed to parse '/Users/lombrozo/Workspace/Playground/eo/hello/.eoc/4-pull/org/eolang/nan.eo:33': Comment must be at least 64 characters long
[ERROR] Failed to parse '/Users/lombrozo/Workspace/Playground/eo/hello/.eoc/4-pull/org/eolang/positive-infinity.eo:39': Comment must be at least 64 characters long
[ERROR] Failed to parse '/Users/lombrozo/Workspace/Playground/eo/hello/.eoc/4-pull/org/eolang/float.eo:103': Comment must be at least 64 characters long
[ERROR] Failed to parse '/Users/lombrozo/Workspace/Playground/eo/hello/.eoc/4-pull/org/eolang/bytes.eo:36': Comment must be at least 64 characters long
[ERROR] Failed to parse '/Users/lombrozo/Workspace/Playground/eo/hello/.eoc/4-pull/org/eolang/nan.eo:36': Comment must be at least 64 characters long
[ERROR] Failed to parse '/Users/lombrozo/Workspace/Playground/eo/hello/.eoc/4-pull/org/eolang/float.eo:106': Comment must be at least 64 characters long
[ERROR] Failed to parse '/Users/lombrozo/Workspace/Playground/eo/hello/.eoc/4-pull/org/eolang/positive-infinity.eo:43': Comment must be at least 64 characters long
[ERROR] Failed to parse '/Users/lombrozo/Workspace/Playground/eo/hello/.eoc/4-pull/org/eolang/bytes.eo:39': Comment must be at least 64 characters long
[ERROR] Failed to parse '/Users/lombrozo/Workspace/Playground/eo/hello/.eoc/4-pull/org/eolang/negative-infinity.eo:29': Comment must be at least 64 characters long
[ERROR] Failed to parse '/Users/lombrozo/Workspace/Playground/eo/hello/.eoc/4-pull/org/eolang/nan.eo:39': Comment must be at least 64 characters long
[ERROR] Failed to parse '/Users/lombrozo/Workspace/Playground/eo/hello/.eoc/4-pull/org/eolang/positive-infinity.eo:43': Comment must contain only ASCII printable characters: 0x20-0x7f
[ERROR] Failed to parse '/Users/lombrozo/Workspace/Playground/eo/hello/.eoc/4-pull/org/eolang/bytes.eo:42': Comment must be at least 64 characters long
[ERROR] Failed to parse '/Users/lombrozo/Workspace/Playground/eo/hello/.eoc/4-pull/org/eolang/negative-infinity.eo:33': Comment must be at least 64 characters long
[ERROR] Failed to parse '/Users/lombrozo/Workspace/Playground/eo/hello/.eoc/4-pull/org/eolang/nan.eo:39': Comment must contain only ASCII printable characters: 0x20-0x7f
[ERROR] Failed to parse '/Users/lombrozo/Workspace/Playground/eo/hello/.eoc/4-pull/org/eolang/bytes.eo:45': Comment must be at least 64 characters long
[ERROR] Failed to parse '/Users/lombrozo/Workspace/Playground/eo/hello/.eoc/4-pull/org/eolang/negative-infinity.eo:39': Comment must be at least 64 characters long
[ERROR] Failed to parse '/Users/lombrozo/Workspace/Playground/eo/hello/.eoc/4-pull/org/eolang/positive-infinity.eo:47': Comment must be at least 64 characters long
[ERROR] Failed to parse '/Users/lombrozo/Workspace/Playground/eo/hello/.eoc/4-pull/org/eolang/nan.eo:42': Comment must be at least 64 characters long
[ERROR] Failed to parse '/Users/lombrozo/Workspace/Playground/eo/hello/.eoc/4-pull/org/eolang/negative-infinity.eo:47': Comment must be at least 64 characters long
[ERROR] Failed to parse '/Users/lombrozo/Workspace/Playground/eo/hello/.eoc/4-pull/org/eolang/bytes.eo:66': Comment must be at least 64 characters long
[ERROR] Failed to parse '/Users/lombrozo/Workspace/Playground/eo/hello/.eoc/4-pull/org/eolang/nan.eo:45': Comment must be at least 64 characters long
[ERROR] Failed to parse '/Users/lombrozo/Workspace/Playground/eo/hello/.eoc/4-pull/org/eolang/positive-infinity.eo:55': Comment must be at least 64 characters long
[ERROR] Failed to parse '/Users/lombrozo/Workspace/Playground/eo/hello/.eoc/4-pull/org/eolang/negative-infinity.eo:47': Comment must contain only ASCII printable characters: 0x20-0x7f
[ERROR] Failed to parse '/Users/lombrozo/Workspace/Playground/eo/hello/.eoc/4-pull/org/eolang/bytes.eo:69': Comment must be at least 64 characters long
[ERROR] Failed to parse '/Users/lombrozo/Workspace/Playground/eo/hello/.eoc/4-pull/org/eolang/positive-infinity.eo:55': Comment must contain only ASCII printable characters: 0x20-0x7f
[ERROR] Failed to parse '/Users/lombrozo/Workspace/Playground/eo/hello/.eoc/4-pull/org/eolang/nan.eo:45': Comment must contain only ASCII printable characters: 0x20-0x7f
[ERROR] Failed to parse '/Users/lombrozo/Workspace/Playground/eo/hello/.eoc/4-pull/org/eolang/negative-infinity.eo:54': Comment must be at least 64 characters long
[ERROR] Failed to parse '/Users/lombrozo/Workspace/Playground/eo/hello/.eoc/4-pull/org/eolang/bytes.eo:72': Comment must be at least 64 characters long
[ERROR] Failed to parse '/Users/lombrozo/Workspace/Playground/eo/hello/.eoc/4-pull/org/eolang/positive-infinity.eo:62': Comment must be at least 64 characters long
[ERROR] Failed to parse '/Users/lombrozo/Workspace/Playground/eo/hello/.eoc/4-pull/org/eolang/nan.eo:48': Comment must be at least 64 characters long
[ERROR] Failed to parse '/Users/lombrozo/Workspace/Playground/eo/hello/.eoc/4-pull/org/eolang/bytes.eo:75': Comment must be at least 64 characters long
[ERROR] Failed to parse '/Users/lombrozo/Workspace/Playground/eo/hello/.eoc/4-pull/org/eolang/negative-infinity.eo:58': Comment must be at least 64 characters long
[ERROR] Failed to parse '/Users/lombrozo/Workspace/Playground/eo/hello/.eoc/4-pull/org/eolang/positive-infinity.eo:91': Comment must be at least 64 characters long
[ERROR] Failed to parse '/Users/lombrozo/Workspace/Playground/eo/hello/.eoc/4-pull/org/eolang/nan.eo:51': Comment must be at least 64 characters long
[ERROR] Failed to parse '/Users/lombrozo/Workspace/Playground/eo/hello/.eoc/4-pull/org/eolang/bytes.eo:78': Comment must be at least 64 characters long
[ERROR] Failed to parse '/Users/lombrozo/Workspace/Playground/eo/hello/.eoc/4-pull/org/eolang/positive-infinity.eo:105': Comment must be at least 64 characters long
[ERROR] Failed to parse '/Users/lombrozo/Workspace/Playground/eo/hello/.eoc/4-pull/org/eolang/nan.eo:54': Comment must be at least 64 characters long
[ERROR] Failed to parse '/Users/lombrozo/Workspace/Playground/eo/hello/.eoc/4-pull/org/eolang/bytes.eo:81': Comment must be at least 64 characters long
[ERROR] Failed to parse '/Users/lombrozo/Workspace/Playground/eo/hello/.eoc/4-pull/org/eolang/negative-infinity.eo:58': Comment must contain only ASCII printable characters: 0x20-0x7f
[ERROR] Failed to parse '/Users/lombrozo/Workspace/Playground/eo/hello/.eoc/4-pull/org/eolang/positive-infinity.eo:119': Comment must be at least 64 characters long
[ERROR] Failed to parse '/Users/lombrozo/Workspace/Playground/eo/hello/.eoc/4-pull/org/eolang/nan.eo:57': Comment must be at least 64 characters long
[ERROR] Failed to parse '/Users/lombrozo/Workspace/Playground/eo/hello/.eoc/4-pull/org/eolang/bytes.eo:84': Comment must be at least 64 characters long
[ERROR] Failed to parse '/Users/lombrozo/Workspace/Playground/eo/hello/.eoc/4-pull/org/eolang/negative-infinity.eo:62': Comment must be at least 64 characters long
[ERROR] Failed to parse '/Users/lombrozo/Workspace/Playground/eo/hello/.eoc/4-pull/org/eolang/nan.eo:60': Comment must be at least 64 characters long
[ERROR] Failed to parse '/Users/lombrozo/Workspace/Playground/eo/hello/.eoc/4-pull/org/eolang/negative-infinity.eo:91': Comment must be at least 64 characters long
[ERROR] Failed to parse '/Users/lombrozo/Workspace/Playground/eo/hello/.eoc/4-pull/org/eolang/negative-infinity.eo:105': Comment must be at least 64 characters long
[ERROR] Failed to parse '/Users/lombrozo/Workspace/Playground/eo/hello/.eoc/4-pull/org/eolang/negative-infinity.eo:119': Comment must be at least 64 characters long
[ERROR] Failed to parse '/Users/lombrozo/Workspace/Playground/eo/hello/.eoc/4-pull/org/eolang/negative-infinity.eo:119': Comment must end with dot
EO program assembled in .eoc
[ERROR] /Users/lombrozo/Workspace/Playground/eo/hello/app.eo, line 4: [4:2] no viable alternative at input '# Comment here.\n[args] > app\n  INTseq > @\n   ': "   *"
[ERROR] net.sf.saxon.style.XSLMessage@5441ce1d: Critical error identified:
  /Users/lombrozo/Workspace/Playground/eo/hello/app.eo, 4: [4:2] no viable alternative at input '# Comment here.\n[args] > app\n  INTseq > @\n   ': "   *";
[ERROR] #fatalError(): Processing terminated by xsl:message at line 31 in fail-on-critical.xsl; SystemID: file:///org/eolang/parser/fail-on-critical.xsl; Line#: 31; Column#: 34
[ERROR] Processing terminated by xsl:message at line 31 in fail-on-critical.xsl
[ERROR] Failed to execute goal org.eolang:eo-maven-plugin:0.38.4:verify (default-cli) on project eoc: 'org.eolang.maven.VerifyMojo@52d6d273' execution failed: java.io.UncheckedIOException: java.io.IOException: java.util.concurrent.ExecutionException: java.lang.IllegalArgumentException: Failed to transform by net.sf.saxon.jaxp.TransformerImpl: ; Processing terminated by xsl:message at line 31 in fail-on-critical.xsl; SystemID: file:///org/eolang/parser/fail-on-critical.xsl; Line#: 31; Column#: 34 -> [Help 1]
[ERROR] 
[ERROR] To see the full stack trace of the errors, re-run Maven with the -e switch.
[ERROR] Re-run Maven using the -X switch to enable full debug logging.
[ERROR] 
[ERROR] For more information about the errors and possible solutions, please read the following articles:
[ERROR] [Help 1] http://cwiki.apache.org/confluence/display/MAVEN/MojoFailureException
The command "/usr/local/lib/node_modules/eolang/mvnw/mvnw eo:verify -Deo.version=0.38.4 -Deo.tag=0.38.4 --quiet -Deo.sourcesDir=/Users/lombrozo/Workspace/Playground/eo/hello -Deo.targetDir=/Users/lombrozo/Workspace/Playground/eo/hello/.eoc -Deo.outputDir=/Users/lombrozo/Workspace/Playground/eo/hello/.eoc/classes -Deo.generatedDir=/Users/lombrozo/Workspace/Playground/eo/hello/.eoc/generated-sources -Deo.placed=/Users/lombrozo/Workspace/Playground/eo/hello/.eoc/eo-placed.csv -Deo.placedFormat=csv --batch-mode --color=never --update-snapshots --fail-fast --strict-checksums" exited with #1 code

What does this message mean?

 no viable alternative at input '# Comment here.\n[args] > app\n  INTseq > @\n   ': "   *";

What should I do to be able to compile simple program with the use of variable?

[volodya-lombrozo]

@maxonfjvipon Could you help here, please?

[maxonfjvipon]

@volodya-lombrozo 2 spaces are required here:

[volodya-lombrozo]

@maxonfjvipon Maybe we can add a more human-readable message for this kind of mistakes? What do you think?

[volodya-lombrozo]

@maxonfjvipon it helped, thank you.

[maxonfjvipon]

@volodya-lombrozo it's a default antl4 parsing error message, I'll check what I can do

[yegor256]

@volodya-lombrozo I believe, it's fixed

[volodya-lombrozo]

@yegor256 How?

[yegor256]

@volodya-lombrozo @maxonfjvipon I suggest closing this one in favor of #3370 (they are very close to each other and once the first one is fixed, the second one will most definitely be fixed too)

[volodya-lombrozo]

@yegor256 I suggest to wait until #3370 is fixed. If it solves the current issue as well, we will close this ticket. Closing the issue now is not safe: If #3370 won't fix this issue, we will just loose this ticket in the history.