@jesscss/fns

@jesscss/fns

The built-in Less/Sass style-function library — color, math, string, and list helpers, split per-file for tree-shaking.

@jesscss/fns is the standard function library for Jess. It provides the built-in functions the language exposes: color operations (lighten, darken, mix, saturate, …), math (round, floor, sqrt, pow, …), unit and type helpers, string helpers, and list/map utilities.

Functions live in their own files and are re-exported from a barrel, so bundlers can tree-shake down to only the helpers you actually use.

@jesscss/fns          → the Less function set (the alpha surface)
@jesscss/fns/builtins → the canonical AST-v2 value-function registry

Only the two entry points above are published in the current alpha. The src/less, src/shared, and src/sass folders are implementation ownership boundaries, not package subpaths: their declaration-only build artifacts are not runtime modules and must not be imported by consumers. Future dialect module entry points will be added only together with a real runtime build and an explicit export contract.

The Sass-side helpers exist in the source tree as part of the roadmap Sass+ work, but SCSS is not the focus of the Less-focused alpha — treat that surface as experimental.

Who uses it

This is an internal engine package. The functions are primarily invoked by the compiler during evaluation, and several expect a Jess evaluation context on this — they are not yet a general-purpose, standalone JavaScript API. Most people should install jess and use the jess CLI. The JavaScript/TypeScript API is not yet stabilized.

Status

Alpha. Published to npm under both the latest and alpha dist-tags. Please report bugs.

Links

• Repository: https://github.com/jesscss/jess
• Documentation: https://jesscss.github.io/ (currently pre-alpha content)

License

MIT