tvl-depot/tvix/eval/docs/builtins.md
Ryan Lahfa e7af8e0d62 feat(tvix/eval): implement appendContext
`appendContext s ctx` will just append a user-crafted context attrs to `s`.

The most important part of this builtin is to perform all the relevant invariant validations
to avoid letting the user craft invalid contexts which can never be built, e.g. invalid store paths,
inexistent derivations, etc.

This version is incomplete and full of TODOs, but passes all the Nix's
context strings tests, so we turn them on.

Change-Id: I625dc5e7c4f5b784f078b390f04b0ee5a8d65a7c
Signed-off-by: Ryan Lahfa <tvl@lahfa.xyz>
Reviewed-on: https://cl.tvl.fyi/c/depot/+/11263
Reviewed-by: flokli <flokli@flokli.de>
Tested-by: BuildkiteCI
2024-04-04 17:24:26 +00:00

138 lines
8.4 KiB
Markdown

Nix builtins
============
Nix has a lot of built-in functions, some of which are accessible in
the global scope, and some of which are only accessible through the
global `builtins` attribute set.
This document is an attempt to track all of these builtins, but
without documenting their functionality.
See also https://nixos.org/manual/nix/stable/expressions/builtins.html
The `impl` column indicates implementation status in tvix:
- implemented: "" (empty cell)
- not yet implemented, but not blocked: `todo`
- not yet implemented, but blocked by other prerequisites:
- `store`: awaiting eval<->store api(s)
- `context`: awaiting support for string contexts
| name | global | arity | pure | impl |
|-------------------------------|--------|-------|-------|---------|
| abort | true | 1 | | |
| add | false | 2 | true | |
| addErrorContext | false | ? | | context |
| all | false | 2 | true | |
| any | false | 2 | true | |
| appendContext | false | ? | | |
| attrNames | false | 1 | true | |
| attrValues | false | | true | |
| baseNameOf | true | | | |
| bitAnd | false | | | |
| bitOr | false | | | |
| bitXor | false | | | |
| builtins | true | | | |
| catAttrs | false | | | |
| compareVersions | false | | | |
| concatLists | false | | | |
| concatMap | false | | | |
| concatStringsSep | false | | | |
| currentSystem | false | | | |
| currentTime | false | | false | |
| deepSeq | false | | | |
| derivation | true | | | store |
| derivationStrict | true | | | store |
| dirOf | true | | | |
| div | false | | | |
| elem | false | | | |
| elemAt | false | | | |
| false | true | | | |
| fetchGit | true | | | store |
| fetchMercurial | true | | | store |
| fetchTarball | true | | | store |
| fetchurl | false | | | store |
| filter | false | | | |
| filterSource | false | | | store |
| findFile | false | | false | todo |
| foldl' | false | | | |
| fromJSON | false | | | |
| fromTOML | true | | | |
| functionArgs | false | | | |
| genList | false | | | |
| genericClosure | false | | | todo |
| getAttr | false | | | |
| getContext | false | | | |
| getEnv | false | | false | |
| hasAttr | false | | | |
| hasContext | false | | | |
| hashFile | false | | false | |
| hashString | false | | | |
| head | false | | | |
| import | true | | | |
| intersectAttrs | false | | | |
| isAttrs | false | | | |
| isBool | false | | | |
| isFloat | false | | | |
| isFunction | false | | | |
| isInt | false | | | |
| isList | false | | | |
| isNull | true | | | |
| isPath | false | | | |
| isString | false | | | |
| langVersion | false | | | |
| length | false | | | |
| lessThan | false | | | |
| listToAttrs | false | | | |
| map | true | | | |
| mapAttrs | false | | | |
| match | false | | | |
| mul | false | | | |
| nixPath | false | | | todo |
| nixVersion | false | | | todo |
| null | true | | | |
| parseDrvName | false | | | |
| partition | false | | | |
| path | false | | sometimes | store |
| pathExists | false | | false | |
| placeholder | true | | | context |
| readDir | false | | false | |
| readFile | false | | false | |
| removeAttrs | true | | | |
| replaceStrings | false | | | |
| scopedImport | true | | | |
| seq | false | | | |
| sort | false | | | |
| split | false | | | |
| splitVersion | false | | | |
| storeDir | false | | | store |
| storePath | false | | | store |
| stringLength | false | | | |
| sub | false | | | |
| substring | false | | | |
| tail | false | | | |
| throw | true | | | |
| toFile | false | | | store |
| toJSON | false | | | |
| toPath | false | | | |
| toString | true | | | |
| toXML | true | | | |
| trace | false | | | |
| true | true | | | |
| tryEval | false | | | |
| typeOf | false | | | |
| unsafeDiscardOutputDependency | false | | | |
| unsafeDiscardStringContext | false | | | |
| unsafeGetAttrPos | false | | | todo |
| valueSize | false | | | todo |
## Added after C++ Nix 2.3 (without Flakes enabled)
| name | global | arity | pure | impl |
|---------------|--------|-------|-------|-------|
| break | false | 1 | | todo |
| ceil | false | 1 | true | |
| fetchTree | true | 1 | | todo |
| floor | false | 1 | true | |
| groupBy | false | 2 | true | |
| traceVerbose | false | 2 | | todo |
| zipAttrsWith | false | 2 | true | todo |