# SuperbChemistry

This is an extension for [OpenOffice](https://www.openoffice.org/) and
[LibreOffice](https://www.libreoffice.org/) that applies superscript and
subscript formatting to chemical formulas in bulk in Writer documents.  See [the
web page](https://mattmccutchen.net/superbchemistry/) for user documentation.

The rest of this document refers to LibreOffice, but the same remarks apply to
OpenOffice.

## Development

Run `make clean all` to generate `SuperbChemistry.oxt`, which you can install in
LibreOffice via "Tools" -> "Extension Manager".

By default, the library is installed read-only to prevent users from making
changes that would be lost without warning if they uninstall the extension.  For
development, you can change `library:readonly="true"` to
`library:readonly="false"` in `extension/SuperbChemistry/*.xlb` so you can edit
the library in LibreOffice.  Then you can copy the edited `Main.xba` from your
profile (a typical location is
`~/.config/libreoffice/4/user/uno_packages/cache/uno_packages/*.tmp_/SuperbChemistry.oxt/SuperbChemistry/Main.xba`,
but this will depend on your operating system and application version) back to
this working tree.

`SuperbChemistry-test.odt` is a test suite that exercises most cases of the
formatting rules.

## Formatting rules

- An _item_ is an element symbol (`[A-Z][a-z]?`) or text that starts or ends
  with a group symbol `()[]{}` (depending on which side of the item we're
  looking at).
- A _charge symbol_ is `+`, `-` (U+002D hyphen-minus), or `−` (U+2212 minus
  sign).
- We recognize the following sequences:
  - An item followed by one or more digits and one of the following: another
    item, space or tab, closing group symbol `)]}`, sentence punctuation
    `.,:;?!'"`, or end of line.
  - An item followed by zero or more digits, a charge symbol, and any of the
    things allowed in the previous case except for another item (to avoid
    matching compound words like `A-B`).  This means we won't match something
    like `Na+Cl-` , but formulas are rarely written that way.
- A recognized charge symbol of `-` is replaced with `−`.
- In a recognized sequence with no charge symbol, all of the digits are treated
  as a quantity.
- In a recognized sequence with a charge symbol, the last digit is treated as a
  charge amount and the rest are treated as a quantity.  For example, in `Fe3+`,
  the digit should be a charge amount.  Exception: if there is only one digit,
  it is treated as a quantity in two cases:
  - If the item is `H`, `O`, `F`, `Cl`, `Br`, or `I`, because these elements
    often occur in quantities greater than 1 and rarely have a charge greater
    than 1.
  - If the item ends in a closing group symbol, because it probably wouldn't
    have been enclosed in group symbols if its quantity were 1.

## License

I, Matt McCutchen, the sole author of SuperbChemistry, waive my copyright to it,
placing it in the public domain.  SuperbChemistry comes with absolutely no
warranty.