WIP Scala 3 Language Specification

This is still a work in progress. There are still Scala 3 features missing, as well as some areas that have not been updated since 2.13 yet.

First of all, the language specification is meant to be correct, precise and clear.

Second, editing, previewing and generating output for the markdown should be simple and easy.

Third, we'd like to support different output formats. An html page per chapter with MathJax seems like a good start, as it satisfies the second requirement, and enables the first one.

Editing

We are using Jekyll and Redcarpet to generate the html.

Check Gemfile for the current versions.

We aim to track the configuration GitHub Pages uses but differences may arise as GitHub Pages evolves.

Building

To preview locally, run the following commands in the docs/_spec subfolder:

env UID="$(id -u)" GID="$(id -g)" docker-compose up

and open http://0.0.0.0:4000/files/archive/spec/3.4/ to view the spec. Jekyll will rebuild as you edit the markdown, but make sure to restart it when you change _config.yml.

General Advice for editors

• All files must be saved as UTF-8: ensure your editors are configured appropriately.

• Use of the appropriate unicode characters instead of the latex modifiers for accents, etc. is necessary. For example, é instead of \'e.

• MathJAX errors will appear within the rendered DOM as span elements with class mtext and style attribute color: red applied. It is possible to search for this combination in the development tools of the browser of your choice. In chrome, CTRL+F / CMD+F within the inspect element panel allows you to do this.

• This document follows the "one sentence <=> one line" convention, with the following exceptions below.

  • A multiline code block is part of the sentence
  • An enumeration of links is long enough

• Whenever doing an enumeration of the kind "a, ..., z", follow the following conventions:

  • It should always be "separator whitespace period period period separator whitespace", for example , ..., or ,\n...,\n for multiline.
  • If in a code block, only the elements (a and z above) should be in math mode (between forward ticks)
  • If in a math expression, the whole thing should be in a single math mode
  • Look at the Tuple Types section for an example of the different cases above.

• Try to use "Note" blocks to point out logical conclusions that are not obvious, for examples, look at the Tuple Types section.

Macro replacements:

• While MathJAX just support LaTeX style command definition, it is recommended to not use this as it will likely cause issues with preparing the document for PDF or ebook distribution.
• \SS (which I could not find defined within the latex source) seems to be closest to \mathscr{S}
• \TYPE is equivalent to `\boldsymbol{type}'
• As MathJAX has no support for slanted font (latex command \sl), so in all instances this should be replaced with \mathit{}
• The macro \U{ABCD} used for unicode character references can be replaced with \uABCD.
• The macro \URange{ABCD}{DCBA} used for unicode character ranges can be replaced with \uABCD-\uDBCA.
• The macro \commadots can be replaced with , … , (But should not, see above).
• There is no adequate replacement for \textsc{...} (small caps) in pandoc markdown. While unicode contains a number of small capital letters, it is notably missing Q and X as these glyphs are intended for phonetic spelling, therefore these cannot be reliably used. For now, the best option is to use underscore emphasis and capitalise the text manually, _LIKE THIS_.

Unicode Character replacements

• The unicode left and right single quotation marks (‘ and ’ (U+2018 and U+2019, respectively)) have been used in place of ` and ', where the quotation marks are intended to be paired. These can be typed on a mac using Option+] for a left quote and Option+Shift+] for the right quote.
• Similarly for left and right double quotation marks (“ and ” (U+201C and U+201D, respectively)) in place of ". These can be typed on a mac using Option+[ and Option+Shift+].