v0.2.0

[jngls]

This is a complete re-write of the proc macro code and addition of specific impls to address the Display blanket impl code gen explosion.

It contains breaking changes so be sure to check the migration notes.

Summary

• Complete proc macro rewrite
• Reduced blanket implementation sprawl
• Better Rust compatibility
  • Relaxed edition to 2021
  • Relaxed MSRV to 1.70
• Docs update
• Readme update
• Version bump to 0.2.0
• Split prefix and suffix args
  • pre for specifying prefix, eg pre = "prefix_"
  • suf for specifying suffix, eg suf = "_suffix"
  • The old format string was not a real format string in the vein of format!(...), nor did it reduce character counts in syntax attribute arguments, so it was removed
• Content replacement
  • cont allows for field or type content replacement and accepts any value that implements SyntaxFmt
  • cont_with allows for field or type content replacement using functions or closures
• Automatic layout control
  • ind for specifying indent regions. Actually writing the indentation is now automatic as long as you use the new nl argument.
  • nl for writing newlines to various locations beg (beginning), pre (after prefix), cont (after field or type content), suf (after suffix).
  • Multiple inserted newlines are possible via array syntax, eg nl = [beg, suf]
  • newline builder method of SyntaxDisplay for setting newline character sequences, eg syntax_fmt(&...).newline(["", "\r\n"])
  • indent builder method of SyntaxDisplay now takes array parameter, eg syntax_fmt(&...).indent(["", "\t"])
• Most args can now take optional array syntax for modal customisation (to distinguish between normal and pretty)
  • delim can now optionally take array syntax, eg delim = ["::", " :: "]
  • pre can optionally take array syntax, eg pre = ["normal_prefix_", "pretty_prefix_"]
  • suf can optionally take array syntax, eg suf = ["_normal_suffix", "_pretty_suffix"]
  • cont can optionally take array syntax, eg cont = ["normal", "***pretty***"]
• Better conditional field evaluation
  • eval allows for conditional field evaluation logic using direct field access
  • eval_with allows for conditional field evaluation logic using functions or closures
  • #[syntax_else(...)] attribute allows for full formatting of eval and eval_with "else" case
• Better control over state types
  • bound specifies the trait bound to be passed through for custom formatters and explicit SyntaxFmt implementations
  • state specifies the concrete state type to be passed through for custom formatters and explicit SyntaxFmt implementations

Breaking Changes and Migration Notes

• Attribute argument changes
  • In cases where you used format, use pre = "prefix_" and/or suf = "_suffix" or to define different prefixes and suffixes depending on mode (normal or pretty), use pre = ["normal_prefix_", "pretty_prefix_"] and/or suf = ["_normal_suffix", "_pretty_suffix"] (see Adding Decorations)
  • In cases where you used pretty_format, use pre and/or suf as explained above for format
  • In cases where you used pretty_delim, use delim = ["normal", "pretty"] instead (see Collections and Delimiters)
  • In cases where you used empty_suffix, use eval = xyz followed by the new attribute #[syntax_else(...)] on a new line (see Conditional Formatting and Fallback Format)
  • In cases where you used indent, remove it (indentation is now automatic as long as you use the new nl arg) (see Indentation and Layout)
  • In cases where you used indent_region, use ind (see Indentation and Layout)
  • In cases where you used state_bound, use bound (see Additional State Examples)
• Newlines and indentation
  • Previously, it was required to place newlines inline in format or delim strings. You can still inline newlines in pre, suf, and delim strings, but you should try to instead use the new nl attribute arg as it deals with automatic indentation (see Indentation and Layout)
  • Previously, it was required to manually specify the indent attribute on every field or type. Now, all newlines triggered by the nl attribute arg are automatically indented (see Indentation and Layout)

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This discussion was created from the release v0.2.0.