Backtrack

Backtrack is a simple and performant Typst library that determines the current
compiler version and provides an API for comparing, displaying, and observing
versions.

Unlike the built-in version API which is only available on
Typst 0.9.0+, Backtrack works on any* Typst version. It uses
the built-in API when available so that it'll continue to work on all future
Typst versions without modification.

Additionally, it:

doesn't noticeably impact compilation time. All version checks are extremely
simple, and newer versions are checked first to avoid overhead from supporting
old versions.
is automatically tested on every supported Typst version to ensure
reliability.
can be downloaded and installed manually in addition to being available as a
package.

Example

#import "@preview/backtrack:1.0.0": current-version, versions

You are using Typst #current-version.displayable!
#{
  if current-version.cmpable <= versions.v2023-03-28.cmpable [
    That is ancient.
  ] else if current-version.cmpable < versions.v0-5-0.cmpable [
    That is old.
  ] else [
    That is modern.
  ]
}

Installation

There are two ways to install the library:

Use the package on Typst 0.6.0+. This is as simple as adding the following
line to your document:
```
#import "@preview/backtrack:1.0.0"
```
Download and install the library manually:
1. Download and extract the latest release.
2. Rename src/lib.typ to src/backtrack.typ.
3. Move/copy COPYING into src/.
4. Rename the src/ directory to backtrack/.
5. Move/copy the newly-renamed backtrack/ directory into your project.
6. Add the following line to your document:
```
#import "[path/to/]backtrack/backtrack.typ"
```

Documentation

See DOCS.md. It's quite short. 😀

Version Support

Backtrack compiles on and can detect these versions:

Version	Status	Notes
0.6.0+	✅	Also available as a package
March 28, 2023–0.5.0	✅
March 21, 2023	✅	Initial public/standalone Typst release
February 25, 2023	🟡	Detects as February 15, 2023
February 12–15, 2023	✅
February 2, 2023	🟡	Detects as January 30, 2023
January 30, 2023	✅

The partially-supported versions may be possible to detect, but they're tricky
since most of their changes are content-related. Content values were opaque up
until the March 21, 2023 release, making it difficult to automatically check for
the presence of these changes.

Copying

Backtrack is licensed under the Apache License, Version 2.0. You can find a copy
of the license in COPYING or online at
https://www.apache.org/licenses/LICENSE-2.0.

backtrack

Package Information

1. Get the package

2. Import in your Typst file