Handle Invalid Java Identifiers

[scottschreckengaust]

Describe the feature

How might invalid java identifiers, https://docs.oracle.com/javase/specs/jls/se12/html/jls-3.html#jls-3.8, be handled?

Here is a reference for "Package Names and Module Names" https://docs.oracle.com/javase/specs/jls/se12/html/jls-6.html#jls-6.1

• If the domain name contains a hyphen, or any other special character not allowed in an identifier (§3.8), convert it into an underscore.
• If any of the resulting package name components are keywords (§3.9), append an underscore to them.
• If any of the resulting package name components start with a digit, or any other character that is not allowed as an initial character of an identifier, have an underscore prefixed to the component.

Use Case

Here is a snippet I used to correct the issue within Projen because hyphens, -, aren't legal characters for java packages:

  publishToMaven: {
  ...
    javaPackage: `io.github.${"no-hyphens".replace(/-/g, '_')}`,
  ...
  },

Proposed Solution

Two options:

1. A ERROR/FAIL message stating invalid java identifiers detected
2. A WARN message stating invalid java identifiers converted

Other Information

When using hypens, -, for example, there are tons of compilation errors and somewhat difficult to trace:

error: '(' or '[' expected
error: ';' expected
error: '{' expected
error: <identifier> expected

...
private final io.github.no-hypens.Builder props;
...

Acknowledgements

• I may be able to implement this feature request
• This feature might incur a breaking change

CDK version used

2.148.0

Environment details (OS name and version, etc.)

macOS Sonoma 14.5